From 3380bd1ed372ed645521137b1f3695d342db1c0f Mon Sep 17 00:00:00 2001 From: Jan Eitzinger Date: Wed, 18 Mar 2026 06:14:15 +0100 Subject: [PATCH] Checkpoint: 7e68050cab59 Entire-Session: 5eb20a94-f8df-4979-a0ae-2aa99bfad884 Entire-Strategy: manual-commit Entire-Agent: Claude Code Ephemeral-branch: entire/33bc19c-e3b0c4 --- 7e/68050cab59/0/content_hash.txt | 1 + 7e/68050cab59/0/full.jsonl | 88 ++++++++++++++++++++++++++++++++ 7e/68050cab59/0/metadata.json | 35 +++++++++++++ 7e/68050cab59/0/prompt.txt | 5 ++ 7e/68050cab59/metadata.json | 27 ++++++++++ 5 files changed, 156 insertions(+) create mode 100644 7e/68050cab59/0/content_hash.txt create mode 100644 7e/68050cab59/0/full.jsonl create mode 100644 7e/68050cab59/0/metadata.json create mode 100644 7e/68050cab59/0/prompt.txt create mode 100644 7e/68050cab59/metadata.json diff --git a/7e/68050cab59/0/content_hash.txt b/7e/68050cab59/0/content_hash.txt new file mode 100644 index 00000000..a98006c4 --- /dev/null +++ b/7e/68050cab59/0/content_hash.txt @@ -0,0 +1 @@ +sha256:d57ab76f7a9216dc8c93731c7dec75954b8a9916bafe9dc8817e34bc1f341ce2 \ No newline at end of file diff --git a/7e/68050cab59/0/full.jsonl b/7e/68050cab59/0/full.jsonl new file mode 100644 index 00000000..adba1cf1 --- /dev/null +++ b/7e/68050cab59/0/full.jsonl @@ -0,0 +1,88 @@ +{"type":"file-history-snapshot","messageId":"dc9d1865-6087-4cef-b483-1acd956b7f10","snapshot":{"messageId":"dc9d1865-6087-4cef-b483-1acd956b7f10","trackedFileBackups":{},"timestamp":"2026-03-18T05:08:42.902Z"},"isSnapshotUpdate":false} +{"parentUuid":null,"isSidechain":false,"type":"progress","data":{"type":"hook_progress","hookEvent":"SessionStart","hookName":"SessionStart:clear","command":"entire hooks claude-code session-start"},"parentToolUseID":"af31666f-203f-4717-988b-2be9f38c41b4","toolUseID":"af31666f-203f-4717-988b-2be9f38c41b4","timestamp":"2026-03-18T05:08:42.853Z","uuid":"9c8b439d-4acb-4774-bd8c-1ada92272058","userType":"external","entrypoint":"cli","cwd":"/Users/jan/prg/ClusterCockpit/cc-backend","sessionId":"5eb20a94-f8df-4979-a0ae-2aa99bfad884","version":"2.1.78","gitBranch":"hotfix","slug":"bright-wandering-flurry"} +{"parentUuid":"9c8b439d-4acb-4774-bd8c-1ada92272058","isSidechain":false,"promptId":"6e6c2140-4cee-4dea-b053-88ef3746e514","type":"user","message":{"role":"user","content":"Implement the following plan:\n\n# Metricstore NATS Slow Consumer Analysis & Improvements\n\n## Context\n\nThe metricstore NATS subscription triggers \"slow consumer, messages dropped\" warnings under load. The root cause is that the NATS message callback blocks for too long, causing the nats.go client to detect a slow consumer and drop messages from its internal pending buffer.\n\n## Root Cause Analysis\n\nThere are **three compounding bottlenecks** in the ingestion path:\n\n### 1. Single-threaded inline decoding (primary cause)\n- `metricstore.go:187` calls `ReceiveNats(ms, 1, ctx)` — **workers=1**\n- With workers=1, `DecodeLine()` runs **directly inside the NATS callback** (`lineprotocol.go:82-87`)\n- The NATS client cannot deliver the next message until the callback returns\n- Each `DecodeLine` call parses line protocol, acquires locks on the level tree, and may block on the WAL channel\n\n### 2. Blocking WAL channel send\n- `lineprotocol.go:351`: `WALMessages <- &WALMessage{...}` is a **blocking send**\n- The `WALMessages` channel has a buffer of only 4096 (`walCheckpoint.go:85`)\n- If the single WALStaging goroutine can't drain fast enough (file I/O), this blocks `DecodeLine`, which blocks the NATS callback\n- Under sustained load, the WAL channel fills up and becomes the dominant bottleneck\n\n### 3. Single WALStaging goroutine with per-message I/O\n- `WALStaging()` (`walCheckpoint.go:118-234`) runs as a **single goroutine**\n- It processes messages sequentially: open/lookup file handle → serialize → write via bufio\n- While bufio batches actual syscalls, the goroutine still handles one message at a time\n- File handle lookups (map access) and potential `MkdirAll` calls add latency\n\n### How nats.go detects slow consumers\nThe nats.go library maintains an internal per-subscription message queue. When the callback blocks, messages accumulate. Once the pending count/bytes exceed limits (default: 65536 messages / 64MB), it drops messages and reports \"slow consumer\".\n\n## Proposed Improvements\n\n### Change 1: Increase worker count and channel buffer\n**File:** `pkg/metricstore/metricstore.go:187` and `pkg/metricstore/lineprotocol.go:56`\n\n- Pass `Keys.NumWorkers` (or a dedicated config field) instead of hardcoded `1`\n- Increase the `msgs` channel buffer from `workers*2` to `workers*256` or a dedicated configurable value (default 16384)\n- This parallelizes `DecodeLine()` across multiple goroutines and decouples the NATS callback from processing\n\n```go\n// metricstore.go — change workers from 1 to NumWorkers\nerr = ReceiveNats(ms, Keys.NumWorkers, ctx)\n```\n\n```go\n// lineprotocol.go — larger channel buffer\nmsgs := make(chan []byte, max(workers*256, 8192))\n```\n\n### Change 2: Increase WAL channel buffer\n**File:** `pkg/metricstore/walCheckpoint.go:85`\n\n- Increase from 4096 to 65536 or higher\n- This gives the WAL staging goroutine more headroom during I/O bursts\n\n```go\nvar WALMessages = make(chan *WALMessage, 65536)\n```\n\n### Change 3: Make WAL send non-blocking with overflow logging\n**File:** `pkg/metricstore/lineprotocol.go:350-359`\n\n- Use a non-blocking send with `select/default` and log dropped WAL messages\n- The in-memory store write (line 361) already succeeded — WAL is for crash recovery only\n- A periodic binary snapshot will capture the data anyway; a few missed WAL entries between snapshots are acceptable\n\n```go\nif Keys.Checkpoints.FileFormat == \"wal\" {\n select {\n case WALMessages <- &WALMessage{...}:\n default:\n // WAL channel full — message written to memory store but not WAL.\n // Next binary snapshot will capture it.\n }\n}\n```\n\n### Change 4: Batch WAL writes in WALStaging\n**File:** `pkg/metricstore/walCheckpoint.go:219-231`\n\n- Drain multiple messages per iteration before going back to `select`\n- Periodically flush all writers (e.g., after draining or on a timer)\n\n```go\n// After processing one message from the channel, drain up to N more without blocking\nfor range 256 {\n select {\n case msg := <-WALMessages:\n processMsg(msg)\n default:\n goto flushed\n }\n}\nflushed:\n// Flush all dirty writers\n```\n\n### Change 5 (cc-lib, optional): Set subscription pending limits\n**File:** cc-lib `nats/client.go` — after `conn.Subscribe()`, call `sub.SetPendingLimits()`\n\n- Increase pending message/byte limits on the subscription object\n- This is a cc-lib change and would need a separate PR\n\n## Implementation Priority\n\n| # | Change | Impact | Effort |\n|---|--------|--------|--------|\n| 1 | Increase workers + channel buffer | **High** — parallelizes decoding, decouples callback | Low |\n| 2 | Increase WAL channel buffer | **Medium** — more burst headroom | Trivial |\n| 3 | Non-blocking WAL send | **High** — eliminates WAL as backpressure source | Low |\n| 4 | Batch WAL drain | **Medium** — reduces select overhead | Low |\n| 5 | cc-lib pending limits | **Medium** — increases NATS-side tolerance | Separate repo |\n\nChanges 1-4 are all in cc-backend and can be done together.\n\n## Files to Modify\n\n- `pkg/metricstore/metricstore.go` — worker count parameter (line 187)\n- `pkg/metricstore/lineprotocol.go` — channel buffer size (line 56), non-blocking WAL send (lines 350-359)\n- `pkg/metricstore/walCheckpoint.go` — WAL channel buffer (line 85), batch drain loop (lines 219-231)\n\n## Verification\n\n1. `go build ./...` — ensure compilation\n2. `go test ./pkg/metricstore/...` — run existing tests\n3. Deploy to a test cluster and monitor:\n - Absence of \"slow consumer\" log messages\n - WAL file growth rate (should be similar)\n - Memory usage (larger channel buffers add ~few MB)\n - `pending` and `dropped` counts from the NATS error handler in cc-lib\n\n\nIf you need specific details from before exiting plan mode (like exact code snippets, error messages, or content you generated), read the full transcript at: /Users/jan/.claude/projects/-Users-jan-prg-ClusterCockpit-cc-backend/c276bf22-8137-44c9-a3e4-951a700f423f.jsonl"},"uuid":"dc9d1865-6087-4cef-b483-1acd956b7f10","timestamp":"2026-03-18T05:08:42.606Z","planContent":"# Metricstore NATS Slow Consumer Analysis & Improvements\n\n## Context\n\nThe metricstore NATS subscription triggers \"slow consumer, messages dropped\" warnings under load. The root cause is that the NATS message callback blocks for too long, causing the nats.go client to detect a slow consumer and drop messages from its internal pending buffer.\n\n## Root Cause Analysis\n\nThere are **three compounding bottlenecks** in the ingestion path:\n\n### 1. Single-threaded inline decoding (primary cause)\n- `metricstore.go:187` calls `ReceiveNats(ms, 1, ctx)` — **workers=1**\n- With workers=1, `DecodeLine()` runs **directly inside the NATS callback** (`lineprotocol.go:82-87`)\n- The NATS client cannot deliver the next message until the callback returns\n- Each `DecodeLine` call parses line protocol, acquires locks on the level tree, and may block on the WAL channel\n\n### 2. Blocking WAL channel send\n- `lineprotocol.go:351`: `WALMessages <- &WALMessage{...}` is a **blocking send**\n- The `WALMessages` channel has a buffer of only 4096 (`walCheckpoint.go:85`)\n- If the single WALStaging goroutine can't drain fast enough (file I/O), this blocks `DecodeLine`, which blocks the NATS callback\n- Under sustained load, the WAL channel fills up and becomes the dominant bottleneck\n\n### 3. Single WALStaging goroutine with per-message I/O\n- `WALStaging()` (`walCheckpoint.go:118-234`) runs as a **single goroutine**\n- It processes messages sequentially: open/lookup file handle → serialize → write via bufio\n- While bufio batches actual syscalls, the goroutine still handles one message at a time\n- File handle lookups (map access) and potential `MkdirAll` calls add latency\n\n### How nats.go detects slow consumers\nThe nats.go library maintains an internal per-subscription message queue. When the callback blocks, messages accumulate. Once the pending count/bytes exceed limits (default: 65536 messages / 64MB), it drops messages and reports \"slow consumer\".\n\n## Proposed Improvements\n\n### Change 1: Increase worker count and channel buffer\n**File:** `pkg/metricstore/metricstore.go:187` and `pkg/metricstore/lineprotocol.go:56`\n\n- Pass `Keys.NumWorkers` (or a dedicated config field) instead of hardcoded `1`\n- Increase the `msgs` channel buffer from `workers*2` to `workers*256` or a dedicated configurable value (default 16384)\n- This parallelizes `DecodeLine()` across multiple goroutines and decouples the NATS callback from processing\n\n```go\n// metricstore.go — change workers from 1 to NumWorkers\nerr = ReceiveNats(ms, Keys.NumWorkers, ctx)\n```\n\n```go\n// lineprotocol.go — larger channel buffer\nmsgs := make(chan []byte, max(workers*256, 8192))\n```\n\n### Change 2: Increase WAL channel buffer\n**File:** `pkg/metricstore/walCheckpoint.go:85`\n\n- Increase from 4096 to 65536 or higher\n- This gives the WAL staging goroutine more headroom during I/O bursts\n\n```go\nvar WALMessages = make(chan *WALMessage, 65536)\n```\n\n### Change 3: Make WAL send non-blocking with overflow logging\n**File:** `pkg/metricstore/lineprotocol.go:350-359`\n\n- Use a non-blocking send with `select/default` and log dropped WAL messages\n- The in-memory store write (line 361) already succeeded — WAL is for crash recovery only\n- A periodic binary snapshot will capture the data anyway; a few missed WAL entries between snapshots are acceptable\n\n```go\nif Keys.Checkpoints.FileFormat == \"wal\" {\n select {\n case WALMessages <- &WALMessage{...}:\n default:\n // WAL channel full — message written to memory store but not WAL.\n // Next binary snapshot will capture it.\n }\n}\n```\n\n### Change 4: Batch WAL writes in WALStaging\n**File:** `pkg/metricstore/walCheckpoint.go:219-231`\n\n- Drain multiple messages per iteration before going back to `select`\n- Periodically flush all writers (e.g., after draining or on a timer)\n\n```go\n// After processing one message from the channel, drain up to N more without blocking\nfor range 256 {\n select {\n case msg := <-WALMessages:\n processMsg(msg)\n default:\n goto flushed\n }\n}\nflushed:\n// Flush all dirty writers\n```\n\n### Change 5 (cc-lib, optional): Set subscription pending limits\n**File:** cc-lib `nats/client.go` — after `conn.Subscribe()`, call `sub.SetPendingLimits()`\n\n- Increase pending message/byte limits on the subscription object\n- This is a cc-lib change and would need a separate PR\n\n## Implementation Priority\n\n| # | Change | Impact | Effort |\n|---|--------|--------|--------|\n| 1 | Increase workers + channel buffer | **High** — parallelizes decoding, decouples callback | Low |\n| 2 | Increase WAL channel buffer | **Medium** — more burst headroom | Trivial |\n| 3 | Non-blocking WAL send | **High** — eliminates WAL as backpressure source | Low |\n| 4 | Batch WAL drain | **Medium** — reduces select overhead | Low |\n| 5 | cc-lib pending limits | **Medium** — increases NATS-side tolerance | Separate repo |\n\nChanges 1-4 are all in cc-backend and can be done together.\n\n## Files to Modify\n\n- `pkg/metricstore/metricstore.go` — worker count parameter (line 187)\n- `pkg/metricstore/lineprotocol.go` — channel buffer size (line 56), non-blocking WAL send (lines 350-359)\n- `pkg/metricstore/walCheckpoint.go` — WAL channel buffer (line 85), batch drain loop (lines 219-231)\n\n## Verification\n\n1. `go build ./...` — ensure compilation\n2. `go test ./pkg/metricstore/...` — run existing tests\n3. 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This file is part of cc-backend.\n 3→// Use of this source code is governed by a MIT-style\n 4→// license that can be found in the LICENSE file.\n 5→\n 6→// Package metricstore provides an efficient in-memory time-series metric storage system\n 7→// with support for hierarchical data organization, checkpointing, and archiving.\n 8→//\n 9→// The package organizes metrics in a tree structure (cluster → host → component) and\n 10→// provides concurrent read/write access to metric data with configurable aggregation strategies.\n 11→// Background goroutines handle periodic checkpointing (JSON or Avro format), archiving old data,\n 12→// and enforcing retention policies.\n 13→//\n 14→// Key features:\n 15→// - In-memory metric storage with configurable retention\n 16→// - Hierarchical data organization (selectors)\n 17→// - Concurrent checkpoint/archive workers\n 18→// - Support for sum and average aggregation\n 19→// - NATS integration for metric ingestion\n 20→package metricstore\n 21→\n 22→import (\n 23→\t\"bytes\"\n 24→\t\"context\"\n 25→\t\"encoding/json\"\n 26→\t\"errors\"\n 27→\t\"fmt\"\n 28→\t\"runtime\"\n 29→\t\"runtime/debug\"\n 30→\t\"slices\"\n 31→\t\"sync\"\n 32→\t\"time\"\n 33→\n 34→\t\"github.com/ClusterCockpit/cc-backend/internal/config\"\n 35→\tcclog \"github.com/ClusterCockpit/cc-lib/v2/ccLogger\"\n 36→\t\"github.com/ClusterCockpit/cc-lib/v2/resampler\"\n 37→\t\"github.com/ClusterCockpit/cc-lib/v2/schema\"\n 38→\t\"github.com/ClusterCockpit/cc-lib/v2/util\"\n 39→)\n 40→\n 41→// GlobalState holds the global state for the metric store with thread-safe access.\n 42→type GlobalState struct {\n 43→\tmu sync.RWMutex\n 44→\tlastRetentionTime int64\n 45→\tselectorsExcluded bool\n 46→}\n 47→\n 48→var (\n 49→\tsingleton sync.Once\n 50→\tmsInstance *MemoryStore\n 51→\t// shutdownFunc stores the context cancellation function created in Init\n 52→\t// and is called during Shutdown to cancel all background goroutines\n 53→\tshutdownFunc context.CancelFunc\n 54→\tshutdownFuncMu sync.Mutex // Protects shutdownFunc from concurrent access\n 55→\t// Create a global instance\n 56→\tstate = &GlobalState{}\n 57→)\n 58→\n 59→// NodeProvider provides information about nodes currently in use by running jobs.\n 60→//\n 61→// This interface allows metricstore to query job information without directly\n 62→// depending on the repository package, breaking the import cycle.\n 63→//\n 64→// Implementations should return nodes that are actively processing jobs started\n 65→// before the given timestamp. These nodes will be excluded from retention-based\n 66→// garbage collection to prevent data loss for jobs that are still running or\n 67→// recently completed.\n 68→type NodeProvider interface {\n 69→\t// GetUsedNodes returns a map of cluster names to sorted lists of unique hostnames\n 70→\t// that are currently in use by jobs that started before the given timestamp.\n 71→\t//\n 72→\t// Parameters:\n 73→\t// - ts: Unix timestamp threshold - returns nodes with jobs started before this time\n 74→\t//\n 75→\t// Returns:\n 76→\t// - Map of cluster names to lists of node hostnames that should be excluded from garbage collection\n 77→\t// - Error if the query fails\n 78→\tGetUsedNodes(ts int64) (map[string][]string, error)\n 79→}\n 80→\n 81→// Metric represents a single metric data point to be written to the store.\n 82→type Metric struct {\n 83→\tName string\n 84→\tValue schema.Float\n 85→\t// MetricConfig contains frequency and aggregation settings for this metric.\n 86→\t// If Frequency is 0, configuration will be looked up from MemoryStore.Metrics during Write().\n 87→\tMetricConfig MetricConfig\n 88→}\n 89→\n 90→// MemoryStore is the main in-memory time-series metric storage implementation.\n 91→//\n 92→// It organizes metrics in a hierarchical tree structure where each level represents\n 93→// a component of the system hierarchy (e.g., cluster → host → CPU). Each level can\n 94→// store multiple metrics as time-series buffers.\n 95→//\n 96→// The store is initialized as a singleton via InitMetrics() and accessed via GetMemoryStore().\n 97→// All public methods are safe for concurrent use.\n 98→type MemoryStore struct {\n 99→\tMetrics map[string]MetricConfig\n 100→\troot Level\n 101→\tnodeProvider NodeProvider\n 102→}\n 103→\n 104→// Init initializes the metric store from configuration and starts background workers.\n 105→//\n 106→// This function must be called exactly once before any other metricstore operations.\n 107→// It performs the following initialization steps:\n 108→// 1. Validates and decodes the metric store configuration\n 109→// 2. Configures worker pool size (defaults to NumCPU/2+1, max 10)\n 110→// 3. Loads metric configurations from all registered clusters\n 111→// 4. Restores checkpoints within the retention window\n 112→// 5. Starts background workers for retention, checkpointing, archiving, and monitoring\n 113→// 6. Optionally subscribes to NATS for real-time metric ingestion\n 114→//\n 115→// Parameters:\n 116→// - rawConfig: JSON configuration for the metric store (see MetricStoreConfig)\n 117→// - wg: WaitGroup that will be incremented for each background goroutine started\n 118→//\n 119→// The function will call cclog.Fatal on critical errors during initialization.\n 120→// Use Shutdown() to cleanly stop all background workers started by Init().\n 121→//\n 122→// Note: Signal handling must be implemented by the caller. Call Shutdown() when\n 123→// receiving termination signals to ensure checkpoint data is persisted.\n 124→func Init(rawConfig json.RawMessage, metrics map[string]MetricConfig, wg *sync.WaitGroup) {\n 125→\tstartupTime := time.Now()\n 126→\n 127→\tif rawConfig != nil {\n 128→\t\tconfig.Validate(configSchema, rawConfig)\n 129→\t\tdec := json.NewDecoder(bytes.NewReader(rawConfig))\n 130→\t\tdec.DisallowUnknownFields()\n 131→\t\tif err := dec.Decode(&Keys); err != nil {\n 132→\t\t\tcclog.Abortf(\"[METRICSTORE]> Metric Store Config Init: Could not decode config file '%s'.\\nError: %s\\n\", rawConfig, err.Error())\n 133→\t\t}\n 134→\t}\n 135→\n 136→\t// Set NumWorkers from config or use default\n 137→\tif Keys.NumWorkers <= 0 {\n 138→\t\tKeys.NumWorkers = min(runtime.NumCPU()/2+1, DefaultMaxWorkers)\n 139→\t}\n 140→\tcclog.Debugf(\"[METRICSTORE]> Using %d workers for checkpoint/archive operations\\n\", Keys.NumWorkers)\n 141→\n 142→\t// Pass the config.MetricStoreKeys\n 143→\tInitMetrics(metrics)\n 144→\n 145→\tms := GetMemoryStore()\n 146→\n 147→\td, err := time.ParseDuration(Keys.RetentionInMemory)\n 148→\tif err != nil {\n 149→\t\tcclog.Fatal(err)\n 150→\t}\n 151→\n 152→\trestoreFrom := startupTime.Add(-d)\n 153→\tcclog.Infof(\"[METRICSTORE]> Loading checkpoints newer than %s\\n\", restoreFrom.Format(time.RFC3339))\n 154→\tfiles, err := ms.FromCheckpointFiles(Keys.Checkpoints.RootDir, restoreFrom.Unix())\n 155→\tloadedData := ms.SizeInBytes() / 1024 / 1024 // In MB\n 156→\tif err != nil {\n 157→\t\tcclog.Fatalf(\"[METRICSTORE]> Loading checkpoints failed: %s\\n\", err.Error())\n 158→\t} else {\n 159→\t\tcclog.Infof(\"[METRICSTORE]> Checkpoints loaded (%d files, %d MB, that took %fs)\\n\", files, loadedData, time.Since(startupTime).Seconds())\n 160→\t}\n 161→\n 162→\t// Try to use less memory by forcing a GC run here and then\n 163→\t// lowering the target percentage. The default of 100 means\n 164→\t// that only once the ratio of new allocations execeds the\n 165→\t// previously active heap, a GC is triggered.\n 166→\t// Forcing a GC here will set the \"previously active heap\"\n 167→\t// to a minumum.\n 168→\t// runtime.GC()\n 169→\n 170→\tctx, shutdown := context.WithCancel(context.Background())\n 171→\n 172→\tRetention(wg, ctx)\n 173→\tCheckpointing(wg, ctx)\n 174→\tCleanUp(wg, ctx)\n 175→\tWALStaging(wg, ctx)\n 176→\tMemoryUsageTracker(wg, ctx)\n 177→\n 178→\t// Note: Signal handling has been removed from this function.\n 179→\t// The caller is responsible for handling shutdown signals and calling\n 180→\t// the shutdown() function when appropriate.\n 181→\t// Store the shutdown function for later use by Shutdown()\n 182→\tshutdownFuncMu.Lock()\n 183→\tshutdownFunc = shutdown\n 184→\tshutdownFuncMu.Unlock()\n 185→\n 186→\tif Keys.Subscriptions != nil {\n 187→\t\terr = ReceiveNats(ms, 1, ctx)\n 188→\t\tif err != nil {\n 189→\t\t\tcclog.Fatal(err)\n 190→\t\t}\n 191→\t}\n 192→}\n 193→\n 194→// InitMetrics initializes the singleton MemoryStore instance with the given metric configurations.\n 195→//\n 196→// This function must be called before GetMemoryStore() and can only be called once due to\n 197→// the singleton pattern. It assigns each metric an internal offset for efficient buffer indexing.\n 198→//\n 199→// Parameters:\n 200→// - metrics: Map of metric names to their configurations (frequency and aggregation strategy)\n 201→//\n 202→// Panics if any metric has Frequency == 0, which indicates an invalid configuration.\n 203→//\n 204→// After this call, the global msInstance is ready for use via GetMemoryStore().\n 205→func InitMetrics(metrics map[string]MetricConfig) {\n 206→\tsingleton.Do(func() {\n 207→\t\toffset := 0\n 208→\t\tfor key, cfg := range metrics {\n 209→\t\t\tif cfg.Frequency == 0 {\n 210→\t\t\t\tpanic(\"[METRICSTORE]> invalid frequency\")\n 211→\t\t\t}\n 212→\n 213→\t\t\tmetrics[key] = MetricConfig{\n 214→\t\t\t\tFrequency: cfg.Frequency,\n 215→\t\t\t\tAggregation: cfg.Aggregation,\n 216→\t\t\t\toffset: offset,\n 217→\t\t\t}\n 218→\t\t\toffset += 1\n 219→\t\t}\n 220→\n 221→\t\tmsInstance = &MemoryStore{\n 222→\t\t\troot: Level{\n 223→\t\t\t\tmetrics: make([]*buffer, len(metrics)),\n 224→\t\t\t\tchildren: make(map[string]*Level),\n 225→\t\t\t},\n 226→\t\t\tMetrics: metrics,\n 227→\t\t}\n 228→\t})\n 229→}\n 230→\n 231→// GetMemoryStore returns the singleton MemoryStore instance.\n 232→//\n 233→// Returns the initialized MemoryStore singleton. Calls cclog.Fatal if InitMetrics() was not called first.\n 234→//\n 235→// This function is safe for concurrent use after initialization.\n 236→func GetMemoryStore() *MemoryStore {\n 237→\tif msInstance == nil {\n 238→\t\tcclog.Warnf(\"[METRICSTORE]> MemoryStore not initialized!\")\n 239→\t}\n 240→\n 241→\treturn msInstance\n 242→}\n 243→\n 244→func (ms *MemoryStore) GetMetricFrequency(metricName string) (int64, error) {\n 245→\tif metric, ok := ms.Metrics[metricName]; ok {\n 246→\t\treturn metric.Frequency, nil\n 247→\t}\n 248→\treturn 0, fmt.Errorf(\"[METRICSTORE]> metric %s not found\", metricName)\n 249→}\n 250→\n 251→// SetNodeProvider sets the NodeProvider implementation for the MemoryStore.\n 252→// This must be called during initialization to provide job state information\n 253→// for selective buffer retention during Free operations.\n 254→// If not set, the Free function will fall back to freeing all buffers.\n 255→func (ms *MemoryStore) SetNodeProvider(provider NodeProvider) {\n 256→\tms.nodeProvider = provider\n 257→}\n 258→\n 259→// Shutdown performs a graceful shutdown of the metric store.\n 260→//\n 261→// This function cancels all background goroutines started by Init() and writes\n 262→// a final checkpoint to disk before returning. It should be called when the\n 263→// application receives a termination signal.\n 264→//\n 265→// The function will:\n 266→// 1. Cancel the context to stop all background workers\n 267→// 2. Close the WAL messages channel if using WAL format\n 268→// 3. Write a final checkpoint to preserve in-memory data\n 269→// 4. Log any errors encountered during shutdown\n 270→//\n 271→// Note: This function blocks until the final checkpoint is written.\n 272→func Shutdown() {\n 273→\tshutdownFuncMu.Lock()\n 274→\tdefer shutdownFuncMu.Unlock()\n 275→\tif shutdownFunc != nil {\n 276→\t\tshutdownFunc()\n 277→\t}\n 278→\n 279→\tif Keys.Checkpoints.FileFormat == \"wal\" {\n 280→\t\tclose(WALMessages)\n 281→\t}\n 282→\n 283→\tcclog.Infof(\"[METRICSTORE]> Writing to '%s'...\\n\", Keys.Checkpoints.RootDir)\n 284→\tvar files int\n 285→\tvar err error\n 286→\n 287→\tms := GetMemoryStore()\n 288→\n 289→\tlastCheckpointMu.Lock()\n 290→\tfrom := lastCheckpoint\n 291→\tlastCheckpointMu.Unlock()\n 292→\n 293→\tif Keys.Checkpoints.FileFormat == \"wal\" {\n 294→\t\tvar hostDirs []string\n 295→\t\tfiles, hostDirs, err = ms.ToCheckpointWAL(Keys.Checkpoints.RootDir, from.Unix(), time.Now().Unix())\n 296→\t\tif err == nil {\n 297→\t\t\tRotateWALFilesAfterShutdown(hostDirs)\n 298→\t\t}\n 299→\t} else {\n 300→\t\tfiles, err = ms.ToCheckpoint(Keys.Checkpoints.RootDir, from.Unix(), time.Now().Unix())\n 301→\t}\n 302→\n 303→\tif err != nil {\n 304→\t\tcclog.Errorf(\"[METRICSTORE]> Writing checkpoint failed: %s\\n\", err.Error())\n 305→\t}\n 306→\tcclog.Infof(\"[METRICSTORE]> Done! (%d files written)\\n\", files)\n 307→}\n 308→\n 309→// Retention starts a background goroutine that periodically frees old metric data.\n 310→//\n 311→// This worker runs at half the retention interval and calls Free() to remove buffers\n 312→// older than the configured retention time. It respects the NodeProvider to preserve\n 313→// data for nodes with active jobs.\n 314→//\n 315→// Parameters:\n 316→// - wg: WaitGroup to signal completion when context is cancelled\n 317→// - ctx: Context for cancellation signal\n 318→//\n 319→// The goroutine exits when ctx is cancelled.\n 320→func Retention(wg *sync.WaitGroup, ctx context.Context) {\n 321→\tms := GetMemoryStore()\n 322→\n 323→\twg.Go(func() {\n 324→\t\td, err := time.ParseDuration(Keys.RetentionInMemory)\n 325→\t\tif err != nil {\n 326→\t\t\tcclog.Fatal(err)\n 327→\t\t}\n 328→\t\tif d <= 0 {\n 329→\t\t\treturn\n 330→\t\t}\n 331→\n 332→\t\ttickInterval := d / 2\n 333→\t\tif tickInterval <= 0 {\n 334→\t\t\treturn\n 335→\t\t}\n 336→\t\tticker := time.NewTicker(tickInterval)\n 337→\t\tdefer ticker.Stop()\n 338→\n 339→\t\tfor {\n 340→\t\t\tselect {\n 341→\t\t\tcase <-ctx.Done():\n 342→\t\t\t\treturn\n 343→\t\t\tcase <-ticker.C:\n 344→\t\t\t\tstate.mu.Lock()\n 345→\n 346→\t\t\t\tt := time.Now().Add(-d)\n 347→\n 348→\t\t\t\tstate.lastRetentionTime = t.Unix()\n 349→\n 350→\t\t\t\tcclog.Infof(\"[METRICSTORE]> start freeing buffers (older than %s)...\\n\", t.Format(time.RFC3339))\n 351→\n 352→\t\t\t\tfreed, err := Free(ms, t)\n 353→\t\t\t\tif err != nil {\n 354→\t\t\t\t\tcclog.Errorf(\"[METRICSTORE]> freeing up buffers failed: %s\\n\", err.Error())\n 355→\t\t\t\t} else {\n 356→\t\t\t\t\tcclog.Infof(\"[METRICSTORE]> done: %d buffers freed\\n\", freed)\n 357→\t\t\t\t}\n 358→\n 359→\t\t\t\tstate.mu.Unlock()\n 360→\n 361→\t\t\t\t// Clean up the buffer pool\n 362→\t\t\t\tbufferPool.Clean(state.lastRetentionTime)\n 363→\t\t\t}\n 364→\t\t}\n 365→\t})\n 366→}\n 367→\n 368→// MemoryUsageTracker starts a background goroutine that monitors memory usage.\n 369→//\n 370→// This worker checks actual process memory usage (via runtime.MemStats) periodically\n 371→// and force-frees buffers if memory exceeds the configured cap. It uses FreeOSMemory()\n 372→// to return memory to the OS after freeing buffers, avoiding aggressive GC that causes\n 373→// performance issues.\n 374→//\n 375→// The tracker logs both actual memory usage (heap allocated) and metric data size for\n 376→// visibility into memory overhead from Go runtime structures and allocations.\n 377→//\n 378→// Parameters:\n 379→// - wg: WaitGroup to signal completion when context is cancelled\n 380→// - ctx: Context for cancellation signal\n 381→//\n 382→// The goroutine exits when ctx is cancelled.\n 383→func MemoryUsageTracker(wg *sync.WaitGroup, ctx context.Context) {\n 384→\tms := GetMemoryStore()\n 385→\n 386→\twg.Go(func() {\n 387→\t\tnormalInterval := DefaultMemoryUsageTrackerInterval\n 388→\t\tfastInterval := 30 * time.Second\n 389→\n 390→\t\tif normalInterval <= 0 {\n 391→\t\t\treturn\n 392→\t\t}\n 393→\n 394→\t\tticker := time.NewTicker(normalInterval)\n 395→\t\tdefer ticker.Stop()\n 396→\t\tcurrentInterval := normalInterval\n 397→\n 398→\t\tfor {\n 399→\t\t\tselect {\n 400→\t\t\tcase <-ctx.Done():\n 401→\t\t\t\treturn\n 402→\t\t\tcase <-ticker.C:\n 403→\t\t\t\tvar mem runtime.MemStats\n 404→\t\t\t\truntime.ReadMemStats(&mem)\n 405→\t\t\t\tactualMemoryGB := float64(mem.Alloc) / 1e9\n 406→\t\t\t\tmetricDataGB := ms.SizeInGB()\n 407→\t\t\t\tcclog.Infof(\"[METRICSTORE]> memory usage: %.2f GB actual (%.2f GB metric data)\", actualMemoryGB, metricDataGB)\n 408→\n 409→\t\t\t\tfreedExcluded := 0\n 410→\t\t\t\tfreedEmergency := 0\n 411→\t\t\t\tvar err error\n 412→\n 413→\t\t\t\tstate.mu.RLock()\n 414→\t\t\t\tlastRetention := state.lastRetentionTime\n 415→\t\t\t\tselectorsExcluded := state.selectorsExcluded\n 416→\t\t\t\tstate.mu.RUnlock()\n 417→\n 418→\t\t\t\tif lastRetention != 0 && selectorsExcluded {\n 419→\t\t\t\t\tfreedExcluded, err = ms.Free(nil, lastRetention)\n 420→\t\t\t\t\tif err != nil {\n 421→\t\t\t\t\t\tcclog.Errorf(\"[METRICSTORE]> error while force-freeing the excluded buffers: %s\", err)\n 422→\t\t\t\t\t}\n 423→\n 424→\t\t\t\t\tif freedExcluded > 0 {\n 425→\t\t\t\t\t\tdebug.FreeOSMemory()\n 426→\t\t\t\t\t\tcclog.Infof(\"[METRICSTORE]> done: %d excluded buffers force-freed\", freedExcluded)\n 427→\t\t\t\t\t}\n 428→\t\t\t\t}\n 429→\n 430→\t\t\t\truntime.ReadMemStats(&mem)\n 431→\t\t\t\tactualMemoryGB = float64(mem.Alloc) / 1e9\n 432→\n 433→\t\t\t\tif actualMemoryGB > float64(Keys.MemoryCap) {\n 434→\t\t\t\t\tcclog.Warnf(\"[METRICSTORE]> memory usage %.2f GB exceeds cap %d GB, starting emergency buffer freeing\", actualMemoryGB, Keys.MemoryCap)\n 435→\n 436→\t\t\t\t\t// Use progressive time-based Free with increasing threshold\n 437→\t\t\t\t\t// instead of ForceFree loop — fewer tree traversals, more effective\n 438→\t\t\t\t\td, parseErr := time.ParseDuration(Keys.RetentionInMemory)\n 439→\t\t\t\t\tif parseErr != nil {\n 440→\t\t\t\t\t\tcclog.Errorf(\"[METRICSTORE]> cannot parse retention duration: %s\", parseErr)\n 441→\t\t\t\t\t} else {\n 442→\t\t\t\t\t\tthresholds := []float64{0.75, 0.5, 0.25}\n 443→\t\t\t\t\t\tfor _, fraction := range thresholds {\n 444→\t\t\t\t\t\t\tthreshold := time.Now().Add(-time.Duration(float64(d) * fraction))\n 445→\t\t\t\t\t\t\tfreed, freeErr := ms.Free(nil, threshold.Unix())\n 446→\t\t\t\t\t\t\tif freeErr != nil {\n 447→\t\t\t\t\t\t\t\tcclog.Errorf(\"[METRICSTORE]> error while freeing buffers at %.0f%% retention: %s\", fraction*100, freeErr)\n 448→\t\t\t\t\t\t\t}\n 449→\t\t\t\t\t\t\tfreedEmergency += freed\n 450→\n 451→\t\t\t\t\t\t\tbufferPool.Clear()\n 452→\t\t\t\t\t\t\truntime.GC()\n 453→\t\t\t\t\t\t\truntime.ReadMemStats(&mem)\n 454→\t\t\t\t\t\t\tactualMemoryGB = float64(mem.Alloc) / 1e9\n 455→\n 456→\t\t\t\t\t\t\tif actualMemoryGB < float64(Keys.MemoryCap) {\n 457→\t\t\t\t\t\t\t\tbreak\n 458→\t\t\t\t\t\t\t}\n 459→\t\t\t\t\t\t}\n 460→\t\t\t\t\t}\n 461→\n 462→\t\t\t\t\tbufferPool.Clear()\n 463→\t\t\t\t\tdebug.FreeOSMemory()\n 464→\n 465→\t\t\t\t\truntime.ReadMemStats(&mem)\n 466→\t\t\t\t\tactualMemoryGB = float64(mem.Alloc) / 1e9\n 467→\n 468→\t\t\t\t\tif actualMemoryGB >= float64(Keys.MemoryCap) {\n 469→\t\t\t\t\t\tcclog.Errorf(\"[METRICSTORE]> after emergency frees (%d buffers), memory usage %.2f GB still at/above cap %d GB\", freedEmergency, actualMemoryGB, Keys.MemoryCap)\n 470→\t\t\t\t\t} else {\n 471→\t\t\t\t\t\tcclog.Infof(\"[METRICSTORE]> emergency freeing complete: %d buffers freed, memory now %.2f GB\", freedEmergency, actualMemoryGB)\n 472→\t\t\t\t\t}\n 473→\t\t\t\t}\n 474→\n 475→\t\t\t\t// Adaptive ticker: check more frequently when memory is high\n 476→\t\t\t\tmemoryRatio := actualMemoryGB / float64(Keys.MemoryCap)\n 477→\t\t\t\tif memoryRatio > 0.8 && currentInterval != fastInterval {\n 478→\t\t\t\t\tticker.Reset(fastInterval)\n 479→\t\t\t\t\tcurrentInterval = fastInterval\n 480→\t\t\t\t\tcclog.Infof(\"[METRICSTORE]> memory at %.0f%% of cap, switching to fast check interval (30s)\", memoryRatio*100)\n 481→\t\t\t\t} else if memoryRatio <= 0.8 && currentInterval != normalInterval {\n 482→\t\t\t\t\tticker.Reset(normalInterval)\n 483→\t\t\t\t\tcurrentInterval = normalInterval\n 484→\t\t\t\t\tcclog.Infof(\"[METRICSTORE]> memory at %.0f%% of cap, switching to normal check interval\", memoryRatio*100)\n 485→\t\t\t\t}\n 486→\t\t\t}\n 487→\t\t}\n 488→\t})\n 489→}\n 490→\n 491→// Free removes metric data older than the given time while preserving data for active nodes.\n 492→//\n 493→// This function implements intelligent retention by consulting the NodeProvider (if configured)\n 494→// to determine which nodes are currently in use by running jobs. Data for these nodes is\n 495→// preserved even if older than the retention time.\n 496→//\n 497→// Parameters:\n 498→// - ms: The MemoryStore instance\n 499→// - t: Time threshold - buffers with data older than this will be freed\n 500→//\n 501→// Returns:\n 502→// - Number of buffers freed\n 503→// - Error if NodeProvider query fails\n 504→//\n 505→// Behavior:\n 506→// - If no NodeProvider is set: frees all buffers older than t\n 507→// - If NodeProvider returns empty map: frees all buffers older than t\n 508→// - Otherwise: preserves buffers for nodes returned by GetUsedNodes(), frees others\n 509→func Free(ms *MemoryStore, t time.Time) (int, error) {\n 510→\t// If no NodeProvider is configured, free all buffers older than t\n 511→\tif ms.nodeProvider == nil {\n 512→\t\treturn ms.Free(nil, t.Unix())\n 513→\t}\n 514→\n 515→\texcludeSelectors, err := ms.nodeProvider.GetUsedNodes(t.Unix())\n 516→\tif err != nil {\n 517→\t\treturn 0, err\n 518→\t}\n 519→\n 520→\tswitch lenMap := len(excludeSelectors); lenMap {\n 521→\n 522→\t// If the length of the map returned by GetUsedNodes() is 0,\n 523→\t// then use default Free method with nil selector\n 524→\tcase 0:\n 525→\t\tstate.selectorsExcluded = false\n 526→\t\treturn ms.Free(nil, t.Unix())\n 527→\n 528→\t// Else formulate selectors, exclude those from the map\n 529→\t// and free the rest of the selectors\n 530→\tdefault:\n 531→\t\tstate.selectorsExcluded = true\n 532→\t\tselectors := GetSelectors(ms, excludeSelectors)\n 533→\t\treturn FreeSelected(ms, selectors, t)\n 534→\t}\n 535→}\n 536→\n 537→// FreeSelected frees buffers for specific selectors while preserving others.\n 538→//\n 539→// This function is used when we want to retain some specific nodes beyond the retention time.\n 540→// It iterates through the provided selectors and frees their associated buffers.\n 541→//\n 542→// Parameters:\n 543→// - ms: The MemoryStore instance\n 544→// - selectors: List of selector paths to free (e.g., [[\"cluster1\", \"node1\"], [\"cluster2\", \"node2\"]])\n 545→// - t: Time threshold for freeing buffers\n 546→//\n 547→// Returns the total number of buffers freed and any error encountered.\n 548→func FreeSelected(ms *MemoryStore, selectors [][]string, t time.Time) (int, error) {\n 549→\tfreed := 0\n 550→\n 551→\tfor _, selector := range selectors {\n 552→\n 553→\t\tfreedBuffers, err := ms.Free(selector, t.Unix())\n 554→\t\tif err != nil {\n 555→\t\t\tcclog.Errorf(\"error while freeing selected buffers: %#v\", err)\n 556→\t\t}\n 557→\t\tfreed += freedBuffers\n 558→\n 559→\t}\n 560→\n 561→\treturn freed, nil\n 562→}\n 563→\n 564→// GetSelectors returns all selectors at depth 2 (cluster/node level) that are NOT in the exclusion map.\n 565→//\n 566→// This function generates a list of selectors whose buffers should be freed by excluding\n 567→// selectors that correspond to nodes currently in use by running jobs.\n 568→//\n 569→// Parameters:\n 570→// - ms: The MemoryStore instance\n 571→// - excludeSelectors: Map of cluster names to node hostnames that should NOT be freed\n 572→//\n 573→// Returns a list of selectors ([]string paths) that can be safely freed.\n 574→//\n 575→// Example:\n 576→//\n 577→//\tIf the tree has paths [\"emmy\", \"node001\"] and [\"emmy\", \"node002\"],\n 578→//\tand excludeSelectors contains {\"emmy\": [\"node001\"]},\n 579→//\tthen only [[\"emmy\", \"node002\"]] is returned.\n 580→func GetSelectors(ms *MemoryStore, excludeSelectors map[string][]string) [][]string {\n 581→\tallSelectors := ms.GetPaths(2)\n 582→\n 583→\tfilteredSelectors := make([][]string, 0, len(allSelectors))\n 584→\n 585→\tfor _, path := range allSelectors {\n 586→\t\tif len(path) < 2 {\n 587→\t\t\tcontinue\n 588→\t\t}\n 589→\n 590→\t\tkey := path[0] // The \"Key\" (Level 1)\n 591→\t\tvalue := path[1] // The \"Value\" (Level 2)\n 592→\n 593→\t\texclude := false\n 594→\n 595→\t\t// Check if the key exists in our exclusion map\n 596→\t\tif excludedValues, exists := excludeSelectors[key]; exists {\n 597→\t\t\t// The key exists, now check if the specific value is in the exclusion list\n 598→\t\t\tif slices.Contains(excludedValues, value) {\n 599→\t\t\t\texclude = true\n 600→\t\t\t}\n 601→\t\t}\n 602→\n 603→\t\tif !exclude {\n 604→\t\t\tfilteredSelectors = append(filteredSelectors, path)\n 605→\t\t}\n 606→\t}\n 607→\n 608→\treturn filteredSelectors\n 609→}\n 610→\n 611→// GetPaths returns a list of lists (paths) to the specified depth.\n 612→func (ms *MemoryStore) GetPaths(targetDepth int) [][]string {\n 613→\tvar results [][]string\n 614→\n 615→\t// Start recursion. Initial path is empty.\n 616→\t// We treat Root as depth 0.\n 617→\tms.root.collectPaths(0, targetDepth, []string{}, &results)\n 618→\n 619→\treturn results\n 620→}\n 621→\n 622→// Write all values in `metrics` to the level specified by `selector` for time `ts`.\n 623→// Look at `findLevelOrCreate` for how selectors work.\n 624→func (m *MemoryStore) Write(selector []string, ts int64, metrics []Metric) error {\n 625→\tvar ok bool\n 626→\tfor i, metric := range metrics {\n 627→\t\tif metric.MetricConfig.Frequency == 0 {\n 628→\t\t\tmetric.MetricConfig, ok = m.Metrics[metric.Name]\n 629→\t\t\tif !ok {\n 630→\t\t\t\tcclog.Debugf(\"[METRICSTORE]> Unknown metric '%s' in Write() - skipping\", metric.Name)\n 631→\t\t\t\tmetric.MetricConfig.Frequency = 0\n 632→\t\t\t}\n 633→\t\t\tmetrics[i] = metric\n 634→\t\t}\n 635→\t}\n 636→\n 637→\treturn m.WriteToLevel(&m.root, selector, ts, metrics)\n 638→}\n 639→\n 640→func (m *MemoryStore) GetLevel(selector []string) *Level {\n 641→\treturn m.root.findLevelOrCreate(selector, len(m.Metrics))\n 642→}\n 643→\n 644→// WriteToLevel assumes that `minfo` in `metrics` is filled in\n 645→func (m *MemoryStore) WriteToLevel(l *Level, selector []string, ts int64, metrics []Metric) error {\n 646→\tl = l.findLevelOrCreate(selector, len(m.Metrics))\n 647→\tl.lock.Lock()\n 648→\tdefer l.lock.Unlock()\n 649→\n 650→\tfor _, metric := range metrics {\n 651→\t\tif metric.MetricConfig.Frequency == 0 {\n 652→\t\t\tcontinue\n 653→\t\t}\n 654→\n 655→\t\tb := l.metrics[metric.MetricConfig.offset]\n 656→\t\tif b == nil {\n 657→\t\t\t// First write to this metric and level\n 658→\t\t\tb = newBuffer(ts, metric.MetricConfig.Frequency)\n 659→\t\t\tl.metrics[metric.MetricConfig.offset] = b\n 660→\t\t}\n 661→\n 662→\t\tnb, err := b.write(ts, metric.Value)\n 663→\t\tif err != nil {\n 664→\t\t\treturn err\n 665→\t\t}\n 666→\n 667→\t\t// Last write created a new buffer...\n 668→\t\tif b != nb {\n 669→\t\t\tl.metrics[metric.MetricConfig.offset] = nb\n 670→\t\t}\n 671→\t}\n 672→\treturn nil\n 673→}\n 674→\n 675→// Read returns all values for metric `metric` from `from` to `to` for the selected level(s).\n 676→// If the level does not hold the metric itself, the data will be aggregated recursively from the children.\n 677→// The second and third return value are the actual from/to for the data. Those can be different from\n 678→// the range asked for if no data was available.\n 679→func (m *MemoryStore) Read(selector util.Selector, metric string, from, to, resolution int64) ([]schema.Float, int64, int64, int64, error) {\n 680→\tif from > to {\n 681→\t\treturn nil, 0, 0, 0, errors.New(\"[METRICSTORE]> invalid time range\")\n 682→\t}\n 683→\n 684→\tminfo, ok := m.Metrics[metric]\n 685→\tif !ok {\n 686→\t\treturn nil, 0, 0, 0, errors.New(\"[METRICSTORE]> unknown metric: \" + metric)\n 687→\t}\n 688→\n 689→\tn, data := 0, make([]schema.Float, (to-from)/minfo.Frequency+1)\n 690→\n 691→\terr := m.root.findBuffers(selector, minfo.offset, func(b *buffer) error {\n 692→\t\tcdata, cfrom, cto, err := b.read(from, to, data)\n 693→\t\tif err != nil {\n 694→\t\t\treturn err\n 695→\t\t}\n 696→\n 697→\t\tif n == 0 {\n 698→\t\t\tfrom, to = cfrom, cto\n 699→\t\t} else if from != cfrom || to != cto || len(data) != len(cdata) {\n 700→\t\t\tmissingfront, missingback := int((from-cfrom)/minfo.Frequency), int((to-cto)/minfo.Frequency)\n 701→\t\t\tif missingfront != 0 {\n 702→\t\t\t\treturn ErrDataDoesNotAlign\n 703→\t\t\t}\n 704→\n 705→\t\t\tnewlen := len(cdata) - missingback\n 706→\t\t\tif newlen < 1 {\n 707→\t\t\t\treturn ErrDataDoesNotAlign\n 708→\t\t\t}\n 709→\t\t\tcdata = cdata[0:newlen]\n 710→\t\t\tif len(cdata) != len(data) {\n 711→\t\t\t\treturn ErrDataDoesNotAlign\n 712→\t\t\t}\n 713→\n 714→\t\t\tfrom, to = cfrom, cto\n 715→\t\t}\n 716→\n 717→\t\tdata = cdata\n 718→\t\tn += 1\n 719→\t\treturn nil\n 720→\t})\n 721→\n 722→\tif err != nil {\n 723→\t\treturn nil, 0, 0, 0, err\n 724→\t} else if n == 0 {\n 725→\t\treturn nil, 0, 0, 0, ErrNoHostOrMetric\n 726→\t} else if n > 1 {\n 727→\t\tif minfo.Aggregation == AvgAggregation {\n 728→\t\t\tnormalize := 1. / schema.Float(n)\n 729→\t\t\tfor i := 0; i < len(data); i++ {\n 730→\t\t\t\tdata[i] *= normalize\n 731→\t\t\t}\n 732→\t\t} else if minfo.Aggregation != SumAggregation {\n 733→\t\t\treturn nil, 0, 0, 0, errors.New(\"[METRICSTORE]> invalid aggregation\")\n 734→\t\t}\n 735→\t}\n 736→\n 737→\tdata, resolution, err = resampler.LargestTriangleThreeBucket(data, minfo.Frequency, resolution)\n 738→\tif err != nil {\n 739→\t\treturn nil, 0, 0, 0, err\n 740→\t}\n 741→\n 742→\treturn data, from, to, resolution, nil\n 743→}\n 744→\n 745→// Free releases all buffers for the selected level and all its children that\n 746→// contain only values older than `t`.\n 747→func (m *MemoryStore) Free(selector []string, t int64) (int, error) {\n 748→\treturn m.GetLevel(selector).free(t)\n 749→}\n 750→\n 751→// ForceFree unconditionally removes the oldest buffer from each metric chain.\n 752→func (m *MemoryStore) ForceFree() (int, error) {\n 753→\treturn m.GetLevel(nil).forceFree()\n 754→}\n 755→\n 756→func (m *MemoryStore) FreeAll() error {\n 757→\tm.root.lock.Lock()\n 758→\tdefer m.root.lock.Unlock()\n 759→\n 760→\tfor k := range m.root.children {\n 761→\t\tdelete(m.root.children, k)\n 762→\t}\n 763→\n 764→\treturn nil\n 765→}\n 766→\n 767→func (m *MemoryStore) SizeInBytes() int64 {\n 768→\treturn m.root.sizeInBytes()\n 769→}\n 770→\n 771→func (m *MemoryStore) SizeInGB() float64 {\n 772→\treturn float64(m.root.sizeInBytes()) / 1e9\n 773→}\n 774→\n 775→// ListChildren , given a selector, returns a list of all children of the level\n 776→// selected.\n 777→func (m *MemoryStore) ListChildren(selector []string) []string {\n 778→\tlvl := &m.root\n 779→\tfor lvl != nil && len(selector) != 0 {\n 780→\t\tlvl.lock.RLock()\n 781→\t\tnext := lvl.children[selector[0]]\n 782→\t\tlvl.lock.RUnlock()\n 783→\t\tlvl = next\n 784→\t\tselector = selector[1:]\n 785→\t}\n 786→\n 787→\tif lvl == nil {\n 788→\t\treturn nil\n 789→\t}\n 790→\n 791→\tlvl.lock.RLock()\n 792→\tdefer lvl.lock.RUnlock()\n 793→\n 794→\tchildren := make([]string, 0, len(lvl.children))\n 795→\tfor child := range lvl.children {\n 796→\t\tchildren = append(children, child)\n 797→\t}\n 798→\n 799→\treturn children\n 800→}\n 801→"}]},"uuid":"0647179d-caa7-4a0f-b6aa-108a2805f2bf","timestamp":"2026-03-18T05:08:47.882Z","toolUseResult":{"type":"text","file":{"filePath":"/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/metricstore.go","content":"// Copyright (C) NHR@FAU, University Erlangen-Nuremberg.\n// All rights reserved. This file is part of cc-backend.\n// Use of this source code is governed by a MIT-style\n// license that can be found in the LICENSE file.\n\n// Package metricstore provides an efficient in-memory time-series metric storage system\n// with support for hierarchical data organization, checkpointing, and archiving.\n//\n// The package organizes metrics in a tree structure (cluster → host → component) and\n// provides concurrent read/write access to metric data with configurable aggregation strategies.\n// Background goroutines handle periodic checkpointing (JSON or Avro format), archiving old data,\n// and enforcing retention policies.\n//\n// Key features:\n// - In-memory metric storage with configurable retention\n// - Hierarchical data organization (selectors)\n// - Concurrent checkpoint/archive workers\n// - Support for sum and average aggregation\n// - NATS integration for metric ingestion\npackage metricstore\n\nimport (\n\t\"bytes\"\n\t\"context\"\n\t\"encoding/json\"\n\t\"errors\"\n\t\"fmt\"\n\t\"runtime\"\n\t\"runtime/debug\"\n\t\"slices\"\n\t\"sync\"\n\t\"time\"\n\n\t\"github.com/ClusterCockpit/cc-backend/internal/config\"\n\tcclog \"github.com/ClusterCockpit/cc-lib/v2/ccLogger\"\n\t\"github.com/ClusterCockpit/cc-lib/v2/resampler\"\n\t\"github.com/ClusterCockpit/cc-lib/v2/schema\"\n\t\"github.com/ClusterCockpit/cc-lib/v2/util\"\n)\n\n// GlobalState holds the global state for the metric store with thread-safe access.\ntype GlobalState struct {\n\tmu sync.RWMutex\n\tlastRetentionTime int64\n\tselectorsExcluded bool\n}\n\nvar (\n\tsingleton sync.Once\n\tmsInstance *MemoryStore\n\t// shutdownFunc stores the context cancellation function created in Init\n\t// and is called during Shutdown to cancel all background goroutines\n\tshutdownFunc context.CancelFunc\n\tshutdownFuncMu sync.Mutex // Protects shutdownFunc from concurrent access\n\t// Create a global instance\n\tstate = &GlobalState{}\n)\n\n// NodeProvider provides information about nodes currently in use by running jobs.\n//\n// This interface allows metricstore to query job information without directly\n// depending on the repository package, breaking the import cycle.\n//\n// Implementations should return nodes that are actively processing jobs started\n// before the given timestamp. These nodes will be excluded from retention-based\n// garbage collection to prevent data loss for jobs that are still running or\n// recently completed.\ntype NodeProvider interface {\n\t// GetUsedNodes returns a map of cluster names to sorted lists of unique hostnames\n\t// that are currently in use by jobs that started before the given timestamp.\n\t//\n\t// Parameters:\n\t// - ts: Unix timestamp threshold - returns nodes with jobs started before this time\n\t//\n\t// Returns:\n\t// - Map of cluster names to lists of node hostnames that should be excluded from garbage collection\n\t// - Error if the query fails\n\tGetUsedNodes(ts int64) (map[string][]string, error)\n}\n\n// Metric represents a single metric data point to be written to the store.\ntype Metric struct {\n\tName string\n\tValue schema.Float\n\t// MetricConfig contains frequency and aggregation settings for this metric.\n\t// If Frequency is 0, configuration will be looked up from MemoryStore.Metrics during Write().\n\tMetricConfig MetricConfig\n}\n\n// MemoryStore is the main in-memory time-series metric storage implementation.\n//\n// It organizes metrics in a hierarchical tree structure where each level represents\n// a component of the system hierarchy (e.g., cluster → host → CPU). Each level can\n// store multiple metrics as time-series buffers.\n//\n// The store is initialized as a singleton via InitMetrics() and accessed via GetMemoryStore().\n// All public methods are safe for concurrent use.\ntype MemoryStore struct {\n\tMetrics map[string]MetricConfig\n\troot Level\n\tnodeProvider NodeProvider\n}\n\n// Init initializes the metric store from configuration and starts background workers.\n//\n// This function must be called exactly once before any other metricstore operations.\n// It performs the following initialization steps:\n// 1. Validates and decodes the metric store configuration\n// 2. Configures worker pool size (defaults to NumCPU/2+1, max 10)\n// 3. Loads metric configurations from all registered clusters\n// 4. Restores checkpoints within the retention window\n// 5. Starts background workers for retention, checkpointing, archiving, and monitoring\n// 6. Optionally subscribes to NATS for real-time metric ingestion\n//\n// Parameters:\n// - rawConfig: JSON configuration for the metric store (see MetricStoreConfig)\n// - wg: WaitGroup that will be incremented for each background goroutine started\n//\n// The function will call cclog.Fatal on critical errors during initialization.\n// Use Shutdown() to cleanly stop all background workers started by Init().\n//\n// Note: Signal handling must be implemented by the caller. Call Shutdown() when\n// receiving termination signals to ensure checkpoint data is persisted.\nfunc Init(rawConfig json.RawMessage, metrics map[string]MetricConfig, wg *sync.WaitGroup) {\n\tstartupTime := time.Now()\n\n\tif rawConfig != nil {\n\t\tconfig.Validate(configSchema, rawConfig)\n\t\tdec := json.NewDecoder(bytes.NewReader(rawConfig))\n\t\tdec.DisallowUnknownFields()\n\t\tif err := dec.Decode(&Keys); err != nil {\n\t\t\tcclog.Abortf(\"[METRICSTORE]> Metric Store Config Init: Could not decode config file '%s'.\\nError: %s\\n\", rawConfig, err.Error())\n\t\t}\n\t}\n\n\t// Set NumWorkers from config or use default\n\tif Keys.NumWorkers <= 0 {\n\t\tKeys.NumWorkers = min(runtime.NumCPU()/2+1, DefaultMaxWorkers)\n\t}\n\tcclog.Debugf(\"[METRICSTORE]> Using %d workers for checkpoint/archive operations\\n\", Keys.NumWorkers)\n\n\t// Pass the config.MetricStoreKeys\n\tInitMetrics(metrics)\n\n\tms := GetMemoryStore()\n\n\td, err := time.ParseDuration(Keys.RetentionInMemory)\n\tif err != nil {\n\t\tcclog.Fatal(err)\n\t}\n\n\trestoreFrom := startupTime.Add(-d)\n\tcclog.Infof(\"[METRICSTORE]> Loading checkpoints newer than %s\\n\", restoreFrom.Format(time.RFC3339))\n\tfiles, err := ms.FromCheckpointFiles(Keys.Checkpoints.RootDir, restoreFrom.Unix())\n\tloadedData := ms.SizeInBytes() / 1024 / 1024 // In MB\n\tif err != nil {\n\t\tcclog.Fatalf(\"[METRICSTORE]> Loading checkpoints failed: %s\\n\", err.Error())\n\t} else {\n\t\tcclog.Infof(\"[METRICSTORE]> Checkpoints loaded (%d files, %d MB, that took %fs)\\n\", files, loadedData, time.Since(startupTime).Seconds())\n\t}\n\n\t// Try to use less memory by forcing a GC run here and then\n\t// lowering the target percentage. The default of 100 means\n\t// that only once the ratio of new allocations execeds the\n\t// previously active heap, a GC is triggered.\n\t// Forcing a GC here will set the \"previously active heap\"\n\t// to a minumum.\n\t// runtime.GC()\n\n\tctx, shutdown := context.WithCancel(context.Background())\n\n\tRetention(wg, ctx)\n\tCheckpointing(wg, ctx)\n\tCleanUp(wg, ctx)\n\tWALStaging(wg, ctx)\n\tMemoryUsageTracker(wg, ctx)\n\n\t// Note: Signal handling has been removed from this function.\n\t// The caller is responsible for handling shutdown signals and calling\n\t// the shutdown() function when appropriate.\n\t// Store the shutdown function for later use by Shutdown()\n\tshutdownFuncMu.Lock()\n\tshutdownFunc = shutdown\n\tshutdownFuncMu.Unlock()\n\n\tif Keys.Subscriptions != nil {\n\t\terr = ReceiveNats(ms, 1, ctx)\n\t\tif err != nil {\n\t\t\tcclog.Fatal(err)\n\t\t}\n\t}\n}\n\n// InitMetrics initializes the singleton MemoryStore instance with the given metric configurations.\n//\n// This function must be called before GetMemoryStore() and can only be called once due to\n// the singleton pattern. It assigns each metric an internal offset for efficient buffer indexing.\n//\n// Parameters:\n// - metrics: Map of metric names to their configurations (frequency and aggregation strategy)\n//\n// Panics if any metric has Frequency == 0, which indicates an invalid configuration.\n//\n// After this call, the global msInstance is ready for use via GetMemoryStore().\nfunc InitMetrics(metrics map[string]MetricConfig) {\n\tsingleton.Do(func() {\n\t\toffset := 0\n\t\tfor key, cfg := range metrics {\n\t\t\tif cfg.Frequency == 0 {\n\t\t\t\tpanic(\"[METRICSTORE]> invalid frequency\")\n\t\t\t}\n\n\t\t\tmetrics[key] = MetricConfig{\n\t\t\t\tFrequency: cfg.Frequency,\n\t\t\t\tAggregation: cfg.Aggregation,\n\t\t\t\toffset: offset,\n\t\t\t}\n\t\t\toffset += 1\n\t\t}\n\n\t\tmsInstance = &MemoryStore{\n\t\t\troot: Level{\n\t\t\t\tmetrics: make([]*buffer, len(metrics)),\n\t\t\t\tchildren: make(map[string]*Level),\n\t\t\t},\n\t\t\tMetrics: metrics,\n\t\t}\n\t})\n}\n\n// GetMemoryStore returns the singleton MemoryStore instance.\n//\n// Returns the initialized MemoryStore singleton. Calls cclog.Fatal if InitMetrics() was not called first.\n//\n// This function is safe for concurrent use after initialization.\nfunc GetMemoryStore() *MemoryStore {\n\tif msInstance == nil {\n\t\tcclog.Warnf(\"[METRICSTORE]> MemoryStore not initialized!\")\n\t}\n\n\treturn msInstance\n}\n\nfunc (ms *MemoryStore) GetMetricFrequency(metricName string) (int64, error) {\n\tif metric, ok := ms.Metrics[metricName]; ok {\n\t\treturn metric.Frequency, nil\n\t}\n\treturn 0, fmt.Errorf(\"[METRICSTORE]> metric %s not found\", metricName)\n}\n\n// SetNodeProvider sets the NodeProvider implementation for the MemoryStore.\n// This must be called during initialization to provide job state information\n// for selective buffer retention during Free operations.\n// If not set, the Free function will fall back to freeing all buffers.\nfunc (ms *MemoryStore) SetNodeProvider(provider NodeProvider) {\n\tms.nodeProvider = provider\n}\n\n// Shutdown performs a graceful shutdown of the metric store.\n//\n// This function cancels all background goroutines started by Init() and writes\n// a final checkpoint to disk before returning. It should be called when the\n// application receives a termination signal.\n//\n// The function will:\n// 1. Cancel the context to stop all background workers\n// 2. Close the WAL messages channel if using WAL format\n// 3. Write a final checkpoint to preserve in-memory data\n// 4. Log any errors encountered during shutdown\n//\n// Note: This function blocks until the final checkpoint is written.\nfunc Shutdown() {\n\tshutdownFuncMu.Lock()\n\tdefer shutdownFuncMu.Unlock()\n\tif shutdownFunc != nil {\n\t\tshutdownFunc()\n\t}\n\n\tif Keys.Checkpoints.FileFormat == \"wal\" {\n\t\tclose(WALMessages)\n\t}\n\n\tcclog.Infof(\"[METRICSTORE]> Writing to '%s'...\\n\", Keys.Checkpoints.RootDir)\n\tvar files int\n\tvar err error\n\n\tms := GetMemoryStore()\n\n\tlastCheckpointMu.Lock()\n\tfrom := lastCheckpoint\n\tlastCheckpointMu.Unlock()\n\n\tif Keys.Checkpoints.FileFormat == \"wal\" {\n\t\tvar hostDirs []string\n\t\tfiles, hostDirs, err = ms.ToCheckpointWAL(Keys.Checkpoints.RootDir, from.Unix(), time.Now().Unix())\n\t\tif err == nil {\n\t\t\tRotateWALFilesAfterShutdown(hostDirs)\n\t\t}\n\t} else {\n\t\tfiles, err = ms.ToCheckpoint(Keys.Checkpoints.RootDir, from.Unix(), time.Now().Unix())\n\t}\n\n\tif err != nil {\n\t\tcclog.Errorf(\"[METRICSTORE]> Writing checkpoint failed: %s\\n\", err.Error())\n\t}\n\tcclog.Infof(\"[METRICSTORE]> Done! (%d files written)\\n\", files)\n}\n\n// Retention starts a background goroutine that periodically frees old metric data.\n//\n// This worker runs at half the retention interval and calls Free() to remove buffers\n// older than the configured retention time. It respects the NodeProvider to preserve\n// data for nodes with active jobs.\n//\n// Parameters:\n// - wg: WaitGroup to signal completion when context is cancelled\n// - ctx: Context for cancellation signal\n//\n// The goroutine exits when ctx is cancelled.\nfunc Retention(wg *sync.WaitGroup, ctx context.Context) {\n\tms := GetMemoryStore()\n\n\twg.Go(func() {\n\t\td, err := time.ParseDuration(Keys.RetentionInMemory)\n\t\tif err != nil {\n\t\t\tcclog.Fatal(err)\n\t\t}\n\t\tif d <= 0 {\n\t\t\treturn\n\t\t}\n\n\t\ttickInterval := d / 2\n\t\tif tickInterval <= 0 {\n\t\t\treturn\n\t\t}\n\t\tticker := time.NewTicker(tickInterval)\n\t\tdefer ticker.Stop()\n\n\t\tfor {\n\t\t\tselect {\n\t\t\tcase <-ctx.Done():\n\t\t\t\treturn\n\t\t\tcase <-ticker.C:\n\t\t\t\tstate.mu.Lock()\n\n\t\t\t\tt := time.Now().Add(-d)\n\n\t\t\t\tstate.lastRetentionTime = t.Unix()\n\n\t\t\t\tcclog.Infof(\"[METRICSTORE]> start freeing buffers (older than %s)...\\n\", t.Format(time.RFC3339))\n\n\t\t\t\tfreed, err := Free(ms, t)\n\t\t\t\tif err != nil {\n\t\t\t\t\tcclog.Errorf(\"[METRICSTORE]> freeing up buffers failed: %s\\n\", err.Error())\n\t\t\t\t} else {\n\t\t\t\t\tcclog.Infof(\"[METRICSTORE]> done: %d buffers freed\\n\", freed)\n\t\t\t\t}\n\n\t\t\t\tstate.mu.Unlock()\n\n\t\t\t\t// Clean up the buffer pool\n\t\t\t\tbufferPool.Clean(state.lastRetentionTime)\n\t\t\t}\n\t\t}\n\t})\n}\n\n// MemoryUsageTracker starts a background goroutine that monitors memory usage.\n//\n// This worker checks actual process memory usage (via runtime.MemStats) periodically\n// and force-frees buffers if memory exceeds the configured cap. It uses FreeOSMemory()\n// to return memory to the OS after freeing buffers, avoiding aggressive GC that causes\n// performance issues.\n//\n// The tracker logs both actual memory usage (heap allocated) and metric data size for\n// visibility into memory overhead from Go runtime structures and allocations.\n//\n// Parameters:\n// - wg: WaitGroup to signal completion when context is cancelled\n// - ctx: Context for cancellation signal\n//\n// The goroutine exits when ctx is cancelled.\nfunc MemoryUsageTracker(wg *sync.WaitGroup, ctx context.Context) {\n\tms := GetMemoryStore()\n\n\twg.Go(func() {\n\t\tnormalInterval := DefaultMemoryUsageTrackerInterval\n\t\tfastInterval := 30 * time.Second\n\n\t\tif normalInterval <= 0 {\n\t\t\treturn\n\t\t}\n\n\t\tticker := time.NewTicker(normalInterval)\n\t\tdefer ticker.Stop()\n\t\tcurrentInterval := normalInterval\n\n\t\tfor {\n\t\t\tselect {\n\t\t\tcase <-ctx.Done():\n\t\t\t\treturn\n\t\t\tcase <-ticker.C:\n\t\t\t\tvar mem runtime.MemStats\n\t\t\t\truntime.ReadMemStats(&mem)\n\t\t\t\tactualMemoryGB := float64(mem.Alloc) / 1e9\n\t\t\t\tmetricDataGB := ms.SizeInGB()\n\t\t\t\tcclog.Infof(\"[METRICSTORE]> memory usage: %.2f GB actual (%.2f GB metric data)\", actualMemoryGB, metricDataGB)\n\n\t\t\t\tfreedExcluded := 0\n\t\t\t\tfreedEmergency := 0\n\t\t\t\tvar err error\n\n\t\t\t\tstate.mu.RLock()\n\t\t\t\tlastRetention := state.lastRetentionTime\n\t\t\t\tselectorsExcluded := state.selectorsExcluded\n\t\t\t\tstate.mu.RUnlock()\n\n\t\t\t\tif lastRetention != 0 && selectorsExcluded {\n\t\t\t\t\tfreedExcluded, err = ms.Free(nil, lastRetention)\n\t\t\t\t\tif err != nil {\n\t\t\t\t\t\tcclog.Errorf(\"[METRICSTORE]> error while force-freeing the excluded buffers: %s\", err)\n\t\t\t\t\t}\n\n\t\t\t\t\tif freedExcluded > 0 {\n\t\t\t\t\t\tdebug.FreeOSMemory()\n\t\t\t\t\t\tcclog.Infof(\"[METRICSTORE]> done: %d excluded buffers force-freed\", freedExcluded)\n\t\t\t\t\t}\n\t\t\t\t}\n\n\t\t\t\truntime.ReadMemStats(&mem)\n\t\t\t\tactualMemoryGB = float64(mem.Alloc) / 1e9\n\n\t\t\t\tif actualMemoryGB > float64(Keys.MemoryCap) {\n\t\t\t\t\tcclog.Warnf(\"[METRICSTORE]> memory usage %.2f GB exceeds cap %d GB, starting emergency buffer freeing\", actualMemoryGB, Keys.MemoryCap)\n\n\t\t\t\t\t// Use progressive time-based Free with increasing threshold\n\t\t\t\t\t// instead of ForceFree loop — fewer tree traversals, more effective\n\t\t\t\t\td, parseErr := time.ParseDuration(Keys.RetentionInMemory)\n\t\t\t\t\tif parseErr != nil {\n\t\t\t\t\t\tcclog.Errorf(\"[METRICSTORE]> cannot parse retention duration: %s\", parseErr)\n\t\t\t\t\t} else {\n\t\t\t\t\t\tthresholds := []float64{0.75, 0.5, 0.25}\n\t\t\t\t\t\tfor _, fraction := range thresholds {\n\t\t\t\t\t\t\tthreshold := time.Now().Add(-time.Duration(float64(d) * fraction))\n\t\t\t\t\t\t\tfreed, freeErr := ms.Free(nil, threshold.Unix())\n\t\t\t\t\t\t\tif freeErr != nil {\n\t\t\t\t\t\t\t\tcclog.Errorf(\"[METRICSTORE]> error while freeing buffers at %.0f%% retention: %s\", fraction*100, freeErr)\n\t\t\t\t\t\t\t}\n\t\t\t\t\t\t\tfreedEmergency += freed\n\n\t\t\t\t\t\t\tbufferPool.Clear()\n\t\t\t\t\t\t\truntime.GC()\n\t\t\t\t\t\t\truntime.ReadMemStats(&mem)\n\t\t\t\t\t\t\tactualMemoryGB = float64(mem.Alloc) / 1e9\n\n\t\t\t\t\t\t\tif actualMemoryGB < float64(Keys.MemoryCap) {\n\t\t\t\t\t\t\t\tbreak\n\t\t\t\t\t\t\t}\n\t\t\t\t\t\t}\n\t\t\t\t\t}\n\n\t\t\t\t\tbufferPool.Clear()\n\t\t\t\t\tdebug.FreeOSMemory()\n\n\t\t\t\t\truntime.ReadMemStats(&mem)\n\t\t\t\t\tactualMemoryGB = float64(mem.Alloc) / 1e9\n\n\t\t\t\t\tif actualMemoryGB >= float64(Keys.MemoryCap) {\n\t\t\t\t\t\tcclog.Errorf(\"[METRICSTORE]> after emergency frees (%d buffers), memory usage %.2f GB still at/above cap %d GB\", freedEmergency, actualMemoryGB, Keys.MemoryCap)\n\t\t\t\t\t} else {\n\t\t\t\t\t\tcclog.Infof(\"[METRICSTORE]> emergency freeing complete: %d buffers freed, memory now %.2f GB\", freedEmergency, actualMemoryGB)\n\t\t\t\t\t}\n\t\t\t\t}\n\n\t\t\t\t// Adaptive ticker: check more frequently when memory is high\n\t\t\t\tmemoryRatio := actualMemoryGB / float64(Keys.MemoryCap)\n\t\t\t\tif memoryRatio > 0.8 && currentInterval != fastInterval {\n\t\t\t\t\tticker.Reset(fastInterval)\n\t\t\t\t\tcurrentInterval = fastInterval\n\t\t\t\t\tcclog.Infof(\"[METRICSTORE]> memory at %.0f%% of cap, switching to fast check interval (30s)\", memoryRatio*100)\n\t\t\t\t} else if memoryRatio <= 0.8 && currentInterval != normalInterval {\n\t\t\t\t\tticker.Reset(normalInterval)\n\t\t\t\t\tcurrentInterval = normalInterval\n\t\t\t\t\tcclog.Infof(\"[METRICSTORE]> memory at %.0f%% of cap, switching to normal check interval\", memoryRatio*100)\n\t\t\t\t}\n\t\t\t}\n\t\t}\n\t})\n}\n\n// Free removes metric data older than the given time while preserving data for active nodes.\n//\n// This function implements intelligent retention by consulting the NodeProvider (if configured)\n// to determine which nodes are currently in use by running jobs. Data for these nodes is\n// preserved even if older than the retention time.\n//\n// Parameters:\n// - ms: The MemoryStore instance\n// - t: Time threshold - buffers with data older than this will be freed\n//\n// Returns:\n// - Number of buffers freed\n// - Error if NodeProvider query fails\n//\n// Behavior:\n// - If no NodeProvider is set: frees all buffers older than t\n// - If NodeProvider returns empty map: frees all buffers older than t\n// - Otherwise: preserves buffers for nodes returned by GetUsedNodes(), frees others\nfunc Free(ms *MemoryStore, t time.Time) (int, error) {\n\t// If no NodeProvider is configured, free all buffers older than t\n\tif ms.nodeProvider == nil {\n\t\treturn ms.Free(nil, t.Unix())\n\t}\n\n\texcludeSelectors, err := ms.nodeProvider.GetUsedNodes(t.Unix())\n\tif err != nil {\n\t\treturn 0, err\n\t}\n\n\tswitch lenMap := len(excludeSelectors); lenMap {\n\n\t// If the length of the map returned by GetUsedNodes() is 0,\n\t// then use default Free method with nil selector\n\tcase 0:\n\t\tstate.selectorsExcluded = false\n\t\treturn ms.Free(nil, t.Unix())\n\n\t// Else formulate selectors, exclude those from the map\n\t// and free the rest of the selectors\n\tdefault:\n\t\tstate.selectorsExcluded = true\n\t\tselectors := GetSelectors(ms, excludeSelectors)\n\t\treturn FreeSelected(ms, selectors, t)\n\t}\n}\n\n// FreeSelected frees buffers for specific selectors while preserving others.\n//\n// This function is used when we want to retain some specific nodes beyond the retention time.\n// It iterates through the provided selectors and frees their associated buffers.\n//\n// Parameters:\n// - ms: The MemoryStore instance\n// - selectors: List of selector paths to free (e.g., [[\"cluster1\", \"node1\"], [\"cluster2\", \"node2\"]])\n// - t: Time threshold for freeing buffers\n//\n// Returns the total number of buffers freed and any error encountered.\nfunc FreeSelected(ms *MemoryStore, selectors [][]string, t time.Time) (int, error) {\n\tfreed := 0\n\n\tfor _, selector := range selectors {\n\n\t\tfreedBuffers, err := ms.Free(selector, t.Unix())\n\t\tif err != nil {\n\t\t\tcclog.Errorf(\"error while freeing selected buffers: %#v\", err)\n\t\t}\n\t\tfreed += freedBuffers\n\n\t}\n\n\treturn freed, nil\n}\n\n// GetSelectors returns all selectors at depth 2 (cluster/node level) that are NOT in the exclusion map.\n//\n// This function generates a list of selectors whose buffers should be freed by excluding\n// selectors that correspond to nodes currently in use by running jobs.\n//\n// Parameters:\n// - ms: The MemoryStore instance\n// - excludeSelectors: Map of cluster names to node hostnames that should NOT be freed\n//\n// Returns a list of selectors ([]string paths) that can be safely freed.\n//\n// Example:\n//\n//\tIf the tree has paths [\"emmy\", \"node001\"] and [\"emmy\", \"node002\"],\n//\tand excludeSelectors contains {\"emmy\": [\"node001\"]},\n//\tthen only [[\"emmy\", \"node002\"]] is returned.\nfunc GetSelectors(ms *MemoryStore, excludeSelectors map[string][]string) [][]string {\n\tallSelectors := ms.GetPaths(2)\n\n\tfilteredSelectors := make([][]string, 0, len(allSelectors))\n\n\tfor _, path := range allSelectors {\n\t\tif len(path) < 2 {\n\t\t\tcontinue\n\t\t}\n\n\t\tkey := path[0] // The \"Key\" (Level 1)\n\t\tvalue := path[1] // The \"Value\" (Level 2)\n\n\t\texclude := false\n\n\t\t// Check if the key exists in our exclusion map\n\t\tif excludedValues, exists := excludeSelectors[key]; exists {\n\t\t\t// The key exists, now check if the specific value is in the exclusion list\n\t\t\tif slices.Contains(excludedValues, value) {\n\t\t\t\texclude = true\n\t\t\t}\n\t\t}\n\n\t\tif !exclude {\n\t\t\tfilteredSelectors = append(filteredSelectors, path)\n\t\t}\n\t}\n\n\treturn filteredSelectors\n}\n\n// GetPaths returns a list of lists (paths) to the specified depth.\nfunc (ms *MemoryStore) GetPaths(targetDepth int) [][]string {\n\tvar results [][]string\n\n\t// Start recursion. Initial path is empty.\n\t// We treat Root as depth 0.\n\tms.root.collectPaths(0, targetDepth, []string{}, &results)\n\n\treturn results\n}\n\n// Write all values in `metrics` to the level specified by `selector` for time `ts`.\n// Look at `findLevelOrCreate` for how selectors work.\nfunc (m *MemoryStore) Write(selector []string, ts int64, metrics []Metric) error {\n\tvar ok bool\n\tfor i, metric := range metrics {\n\t\tif metric.MetricConfig.Frequency == 0 {\n\t\t\tmetric.MetricConfig, ok = m.Metrics[metric.Name]\n\t\t\tif !ok {\n\t\t\t\tcclog.Debugf(\"[METRICSTORE]> Unknown metric '%s' in Write() - skipping\", metric.Name)\n\t\t\t\tmetric.MetricConfig.Frequency = 0\n\t\t\t}\n\t\t\tmetrics[i] = metric\n\t\t}\n\t}\n\n\treturn m.WriteToLevel(&m.root, selector, ts, metrics)\n}\n\nfunc (m *MemoryStore) GetLevel(selector []string) *Level {\n\treturn m.root.findLevelOrCreate(selector, len(m.Metrics))\n}\n\n// WriteToLevel assumes that `minfo` in `metrics` is filled in\nfunc (m *MemoryStore) WriteToLevel(l *Level, selector []string, ts int64, metrics []Metric) error {\n\tl = l.findLevelOrCreate(selector, len(m.Metrics))\n\tl.lock.Lock()\n\tdefer l.lock.Unlock()\n\n\tfor _, metric := range metrics {\n\t\tif metric.MetricConfig.Frequency == 0 {\n\t\t\tcontinue\n\t\t}\n\n\t\tb := l.metrics[metric.MetricConfig.offset]\n\t\tif b == nil {\n\t\t\t// First write to this metric and level\n\t\t\tb = newBuffer(ts, metric.MetricConfig.Frequency)\n\t\t\tl.metrics[metric.MetricConfig.offset] = b\n\t\t}\n\n\t\tnb, err := b.write(ts, metric.Value)\n\t\tif err != nil {\n\t\t\treturn err\n\t\t}\n\n\t\t// Last write created a new buffer...\n\t\tif b != nb {\n\t\t\tl.metrics[metric.MetricConfig.offset] = nb\n\t\t}\n\t}\n\treturn nil\n}\n\n// Read returns all values for metric `metric` from `from` to `to` for the selected level(s).\n// If the level does not hold the metric itself, the data will be aggregated recursively from the children.\n// The second and third return value are the actual from/to for the data. Those can be different from\n// the range asked for if no data was available.\nfunc (m *MemoryStore) Read(selector util.Selector, metric string, from, to, resolution int64) ([]schema.Float, int64, int64, int64, error) {\n\tif from > to {\n\t\treturn nil, 0, 0, 0, errors.New(\"[METRICSTORE]> invalid time range\")\n\t}\n\n\tminfo, ok := m.Metrics[metric]\n\tif !ok {\n\t\treturn nil, 0, 0, 0, errors.New(\"[METRICSTORE]> unknown metric: \" + metric)\n\t}\n\n\tn, data := 0, make([]schema.Float, (to-from)/minfo.Frequency+1)\n\n\terr := m.root.findBuffers(selector, minfo.offset, func(b *buffer) error {\n\t\tcdata, cfrom, cto, err := b.read(from, to, data)\n\t\tif err != nil {\n\t\t\treturn err\n\t\t}\n\n\t\tif n == 0 {\n\t\t\tfrom, to = cfrom, cto\n\t\t} else if from != cfrom || to != cto || len(data) != len(cdata) {\n\t\t\tmissingfront, missingback := int((from-cfrom)/minfo.Frequency), int((to-cto)/minfo.Frequency)\n\t\t\tif missingfront != 0 {\n\t\t\t\treturn ErrDataDoesNotAlign\n\t\t\t}\n\n\t\t\tnewlen := len(cdata) - missingback\n\t\t\tif newlen < 1 {\n\t\t\t\treturn ErrDataDoesNotAlign\n\t\t\t}\n\t\t\tcdata = cdata[0:newlen]\n\t\t\tif len(cdata) != len(data) {\n\t\t\t\treturn ErrDataDoesNotAlign\n\t\t\t}\n\n\t\t\tfrom, to = cfrom, cto\n\t\t}\n\n\t\tdata = cdata\n\t\tn += 1\n\t\treturn nil\n\t})\n\n\tif err != nil {\n\t\treturn nil, 0, 0, 0, err\n\t} else if n == 0 {\n\t\treturn nil, 0, 0, 0, ErrNoHostOrMetric\n\t} else if n > 1 {\n\t\tif minfo.Aggregation == AvgAggregation {\n\t\t\tnormalize := 1. / schema.Float(n)\n\t\t\tfor i := 0; i < len(data); i++ {\n\t\t\t\tdata[i] *= normalize\n\t\t\t}\n\t\t} else if minfo.Aggregation != SumAggregation {\n\t\t\treturn nil, 0, 0, 0, errors.New(\"[METRICSTORE]> invalid aggregation\")\n\t\t}\n\t}\n\n\tdata, resolution, err = resampler.LargestTriangleThreeBucket(data, minfo.Frequency, resolution)\n\tif err != nil {\n\t\treturn nil, 0, 0, 0, err\n\t}\n\n\treturn data, from, to, resolution, nil\n}\n\n// Free releases all buffers for the selected level and all its children that\n// contain only values older than `t`.\nfunc (m *MemoryStore) Free(selector []string, t int64) (int, error) {\n\treturn m.GetLevel(selector).free(t)\n}\n\n// ForceFree unconditionally removes the oldest buffer from each metric chain.\nfunc (m *MemoryStore) ForceFree() (int, error) {\n\treturn m.GetLevel(nil).forceFree()\n}\n\nfunc (m *MemoryStore) FreeAll() error {\n\tm.root.lock.Lock()\n\tdefer m.root.lock.Unlock()\n\n\tfor k := range m.root.children {\n\t\tdelete(m.root.children, k)\n\t}\n\n\treturn nil\n}\n\nfunc (m *MemoryStore) SizeInBytes() int64 {\n\treturn m.root.sizeInBytes()\n}\n\nfunc (m *MemoryStore) SizeInGB() float64 {\n\treturn float64(m.root.sizeInBytes()) / 1e9\n}\n\n// ListChildren , given a selector, returns a list of all children of the level\n// selected.\nfunc (m *MemoryStore) ListChildren(selector []string) []string {\n\tlvl := &m.root\n\tfor lvl != nil && len(selector) != 0 {\n\t\tlvl.lock.RLock()\n\t\tnext := lvl.children[selector[0]]\n\t\tlvl.lock.RUnlock()\n\t\tlvl = next\n\t\tselector = selector[1:]\n\t}\n\n\tif lvl == nil {\n\t\treturn nil\n\t}\n\n\tlvl.lock.RLock()\n\tdefer lvl.lock.RUnlock()\n\n\tchildren := make([]string, 0, len(lvl.children))\n\tfor child := range lvl.children {\n\t\tchildren = append(children, child)\n\t}\n\n\treturn children\n}\n","numLines":801,"startLine":1,"totalLines":801}},"sourceToolAssistantUUID":"0927b747-336e-4f16-83ff-1fa21bd85ab3","userType":"external","entrypoint":"cli","cwd":"/Users/jan/prg/ClusterCockpit/cc-backend","sessionId":"5eb20a94-f8df-4979-a0ae-2aa99bfad884","version":"2.1.78","gitBranch":"hotfix","slug":"bright-wandering-flurry"} +{"parentUuid":"0647179d-caa7-4a0f-b6aa-108a2805f2bf","isSidechain":false,"message":{"model":"claude-opus-4-6","id":"msg_01FJM15SbFPE9emPyDSmVKXC","type":"message","role":"assistant","content":[{"type":"tool_use","id":"toolu_01XGcPAMBpbMcP5dGZ2Js2xG","name":"Read","input":{"file_path":"/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/lineprotocol.go"},"caller":{"type":"direct"}}],"stop_reason":null,"stop_sequence":null,"usage":{"input_tokens":3,"cache_creation_input_tokens":5791,"cache_read_input_tokens":14412,"cache_creation":{"ephemeral_5m_input_tokens":0,"ephemeral_1h_input_tokens":5791},"output_tokens":9,"service_tier":"standard","inference_geo":"not_available"}},"requestId":"req_011CZ9y59qXYvJaYQc65Pxx9","type":"assistant","uuid":"75b19f05-5eda-4d82-857e-1b7885ece7ad","timestamp":"2026-03-18T05:08:48.121Z","userType":"external","entrypoint":"cli","cwd":"/Users/jan/prg/ClusterCockpit/cc-backend","sessionId":"5eb20a94-f8df-4979-a0ae-2aa99bfad884","version":"2.1.78","gitBranch":"hotfix","slug":"bright-wandering-flurry"} +{"parentUuid":"75b19f05-5eda-4d82-857e-1b7885ece7ad","isSidechain":false,"type":"progress","data":{"type":"hook_progress","hookEvent":"PostToolUse","hookName":"PostToolUse:Read","command":"callback"},"parentToolUseID":"toolu_01XGcPAMBpbMcP5dGZ2Js2xG","toolUseID":"toolu_01XGcPAMBpbMcP5dGZ2Js2xG","timestamp":"2026-03-18T05:08:48.126Z","uuid":"44f41a85-206a-46ea-a91e-2fe0f8c9e6a8","userType":"external","entrypoint":"cli","cwd":"/Users/jan/prg/ClusterCockpit/cc-backend","sessionId":"5eb20a94-f8df-4979-a0ae-2aa99bfad884","version":"2.1.78","gitBranch":"hotfix","slug":"bright-wandering-flurry"} +{"parentUuid":"75b19f05-5eda-4d82-857e-1b7885ece7ad","isSidechain":false,"promptId":"6e6c2140-4cee-4dea-b053-88ef3746e514","type":"user","message":{"role":"user","content":[{"tool_use_id":"toolu_01XGcPAMBpbMcP5dGZ2Js2xG","type":"tool_result","content":" 1→// Copyright (C) NHR@FAU, University Erlangen-Nuremberg.\n 2→// All rights reserved. This file is part of cc-backend.\n 3→// Use of this source code is governed by a MIT-style\n 4→// license that can be found in the LICENSE file.\n 5→\n 6→// This file implements ingestion of InfluxDB line-protocol metric data received\n 7→// over NATS. Each line encodes one metric sample with the following structure:\n 8→//\n 9→//\t[,cluster=][,hostname=][,type=][,type-id=][,subtype=][,stype-id=] value= []\n 10→//\n 11→// The measurement name identifies the metric (e.g. \"cpu_load\"). Tags provide\n 12→// routing information (cluster, host) and optional sub-device selectors (type,\n 13→// subtype). Only one field is expected per line: \"value\".\n 14→//\n 15→// After decoding, each sample is:\n 16→// 1. Written to the in-memory store via ms.WriteToLevel.\n 17→// 2. If the checkpoint format is \"wal\", also forwarded to the WAL staging\n 18→// goroutine via the WALMessages channel for durable write-ahead logging.\n 19→package metricstore\n 20→\n 21→import (\n 22→\t\"bytes\"\n 23→\t\"context\"\n 24→\t\"fmt\"\n 25→\t\"sync\"\n 26→\t\"time\"\n 27→\n 28→\tcclog \"github.com/ClusterCockpit/cc-lib/v2/ccLogger\"\n 29→\t\"github.com/ClusterCockpit/cc-lib/v2/nats\"\n 30→\t\"github.com/ClusterCockpit/cc-lib/v2/schema\"\n 31→\t\"github.com/ClusterCockpit/cc-line-protocol/v2/lineprotocol\"\n 32→)\n 33→\n 34→// ReceiveNats subscribes to all configured NATS subjects and feeds incoming\n 35→// line-protocol messages into the MemoryStore.\n 36→//\n 37→// When workers > 1 a pool of goroutines drains a shared channel so that\n 38→// multiple messages can be decoded in parallel. With workers == 1 the NATS\n 39→// callback decodes inline (no channel overhead, lower latency).\n 40→//\n 41→// The function blocks until ctx is cancelled and all worker goroutines have\n 42→// finished. It returns nil when the NATS client is not configured; callers\n 43→// should treat that as a no-op rather than an error.\n 44→func ReceiveNats(ms *MemoryStore,\n 45→\tworkers int,\n 46→\tctx context.Context,\n 47→) error {\n 48→\tnc := nats.GetClient()\n 49→\n 50→\tif nc == nil {\n 51→\t\tcclog.Warn(\"NATS client not initialized\")\n 52→\t\treturn nil\n 53→\t}\n 54→\n 55→\tvar wg sync.WaitGroup\n 56→\tmsgs := make(chan []byte, workers*2)\n 57→\n 58→\tfor _, sc := range *Keys.Subscriptions {\n 59→\t\tclusterTag := sc.ClusterTag\n 60→\t\tif workers > 1 {\n 61→\t\t\twg.Add(workers)\n 62→\n 63→\t\t\tfor range workers {\n 64→\t\t\t\tgo func() {\n 65→\t\t\t\t\tdefer wg.Done()\n 66→\t\t\t\t\tfor m := range msgs {\n 67→\t\t\t\t\t\tdec := lineprotocol.NewDecoderWithBytes(m)\n 68→\t\t\t\t\t\tif err := DecodeLine(dec, ms, clusterTag); err != nil {\n 69→\t\t\t\t\t\t\tcclog.Errorf(\"error: %s\", err.Error())\n 70→\t\t\t\t\t\t}\n 71→\t\t\t\t\t}\n 72→\t\t\t\t}()\n 73→\t\t\t}\n 74→\n 75→\t\t\tnc.Subscribe(sc.SubscribeTo, func(subject string, data []byte) {\n 76→\t\t\t\tselect {\n 77→\t\t\t\tcase msgs <- data:\n 78→\t\t\t\tcase <-ctx.Done():\n 79→\t\t\t\t}\n 80→\t\t\t})\n 81→\t\t} else {\n 82→\t\t\tnc.Subscribe(sc.SubscribeTo, func(subject string, data []byte) {\n 83→\t\t\t\tdec := lineprotocol.NewDecoderWithBytes(data)\n 84→\t\t\t\tif err := DecodeLine(dec, ms, clusterTag); err != nil {\n 85→\t\t\t\t\tcclog.Errorf(\"error: %s\", err.Error())\n 86→\t\t\t\t}\n 87→\t\t\t})\n 88→\t\t}\n 89→\t\tcclog.Infof(\"NATS subscription to '%s' established\", sc.SubscribeTo)\n 90→\t}\n 91→\n 92→\tgo func() {\n 93→\t\t<-ctx.Done()\n 94→\t\tclose(msgs)\n 95→\t}()\n 96→\n 97→\twg.Wait()\n 98→\n 99→\treturn nil\n 100→}\n 101→\n 102→// reorder prepends prefix to buf in-place when buf has enough spare capacity,\n 103→// avoiding an allocation. Falls back to a regular append otherwise.\n 104→//\n 105→// It is used to assemble the \"type\" and \"subtype\" selector\n 106→// strings when the type tag arrives before the type-id tag in the line, so the\n 107→// two byte slices need to be concatenated in tag-declaration order regardless\n 108→// of wire order.\n 109→func reorder(buf, prefix []byte) []byte {\n 110→\tn := len(prefix)\n 111→\tm := len(buf)\n 112→\tif cap(buf) < m+n {\n 113→\t\treturn append(prefix[:n:n], buf...)\n 114→\t} else {\n 115→\t\tbuf = buf[:n+m]\n 116→\t\tfor i := m - 1; i >= 0; i-- {\n 117→\t\t\tbuf[i+n] = buf[i]\n 118→\t\t}\n 119→\t\tfor i := range n {\n 120→\t\t\tbuf[i] = prefix[i]\n 121→\t\t}\n 122→\t\treturn buf\n 123→\t}\n 124→}\n 125→\n 126→// decodeState holds the per-call scratch buffers used by DecodeLine.\n 127→// Instances are recycled via decodeStatePool to avoid repeated allocations\n 128→// during high-throughput ingestion.\n 129→type decodeState struct {\n 130→\t// metricBuf holds a copy of the current measurement name (line-protocol\n 131→\t// measurement field). Copied because dec.Measurement() returns a slice\n 132→\t// that is invalidated by the next decoder call.\n 133→\tmetricBuf []byte\n 134→\n 135→\t// selector is the sub-device path passed to WriteToLevel and WALMessage\n 136→\t// (e.g. [\"socket0\"] or [\"socket0\", \"memctrl1\"]). Reused across lines.\n 137→\tselector []string\n 138→\n 139→\t// typeBuf accumulates the concatenated \"type\"+\"type-id\" tag value for the\n 140→\t// current line. Reset at the start of each line's tag-decode loop.\n 141→\ttypeBuf []byte\n 142→\n 143→\t// subTypeBuf accumulates the concatenated \"subtype\"+\"stype-id\" tag value.\n 144→\t// Reset at the start of each line's tag-decode loop.\n 145→\tsubTypeBuf []byte\n 146→\n 147→\t// prevTypeBytes / prevTypeStr cache the last seen typeBuf content and its\n 148→\t// string conversion. Because consecutive lines in a batch typically address\n 149→\t// the same sub-device, the cache hit rate is very high and avoids\n 150→\t// repeated []byte→string allocations.\n 151→\tprevTypeBytes []byte\n 152→\tprevTypeStr string\n 153→\n 154→\t// prevSubTypeBytes / prevSubTypeStr are the same cache for the subtype.\n 155→\tprevSubTypeBytes []byte\n 156→\tprevSubTypeStr string\n 157→}\n 158→\n 159→// decodeStatePool recycles decodeState values across DecodeLine calls to\n 160→// reduce GC pressure during sustained metric ingestion.\n 161→var decodeStatePool = sync.Pool{\n 162→\tNew: func() any {\n 163→\t\treturn &decodeState{\n 164→\t\t\tmetricBuf: make([]byte, 0, 16),\n 165→\t\t\tselector: make([]string, 0, 4),\n 166→\t\t\ttypeBuf: make([]byte, 0, 16),\n 167→\t\t\tsubTypeBuf: make([]byte, 0, 16),\n 168→\t\t}\n 169→\t},\n 170→}\n 171→\n 172→// DecodeLine reads all lines from dec (InfluxDB line-protocol) and writes each\n 173→// decoded metric sample into ms.\n 174→//\n 175→// clusterDefault is used as the cluster name for lines that do not carry a\n 176→// \"cluster\" tag. Callers typically supply the ClusterTag value from the NATS\n 177→// subscription configuration.\n 178→//\n 179→// Performance notes:\n 180→// - A decodeState is obtained from decodeStatePool to reuse scratch buffers.\n 181→// - The Level pointer (host-level node in the metric tree) is cached across\n 182→// consecutive lines that share the same cluster+host pair to avoid\n 183→// repeated lock acquisitions on the root and cluster levels.\n 184→// - []byte→string conversions for type/subtype selectors are cached via\n 185→// prevType*/prevSubType* fields because batches typically repeat the same\n 186→// sub-device identifiers.\n 187→// - Timestamp parsing tries Second precision first; if that fails it retries\n 188→// Millisecond, Microsecond, and Nanosecond in turn. A missing timestamp\n 189→// falls back to time.Now().\n 190→//\n 191→// When the checkpoint format is \"wal\" each successfully decoded sample is also\n 192→// sent to WALMessages so the WAL staging goroutine can persist it durably\n 193→// before the next binary snapshot.\n 194→func DecodeLine(dec *lineprotocol.Decoder,\n 195→\tms *MemoryStore,\n 196→\tclusterDefault string,\n 197→) error {\n 198→\t// Reduce allocations in loop:\n 199→\tt := time.Now()\n 200→\tmetric := Metric{}\n 201→\tst := decodeStatePool.Get().(*decodeState)\n 202→\tdefer decodeStatePool.Put(st)\n 203→\n 204→\t// Optimize for the case where all lines in a \"batch\" are about the same\n 205→\t// cluster and host. By using `WriteToLevel` (level = host), we do not need\n 206→\t// to take the root- and cluster-level lock as often.\n 207→\tvar lvl *Level = nil\n 208→\tprevCluster, prevHost := \"\", \"\"\n 209→\n 210→\tvar ok bool\n 211→\tfor dec.Next() {\n 212→\t\trawmeasurement, err := dec.Measurement()\n 213→\t\tif err != nil {\n 214→\t\t\treturn err\n 215→\t\t}\n 216→\n 217→\t\t// Needs to be copied because another call to dec.* would\n 218→\t\t// invalidate the returned slice.\n 219→\t\tst.metricBuf = append(st.metricBuf[:0], rawmeasurement...)\n 220→\n 221→\t\t// The go compiler optimizes map[string(byteslice)] lookups:\n 222→\t\tmetric.MetricConfig, ok = ms.Metrics[string(rawmeasurement)]\n 223→\t\tif !ok {\n 224→\t\t\tcontinue\n 225→\t\t}\n 226→\n 227→\t\tst.typeBuf, st.subTypeBuf = st.typeBuf[:0], st.subTypeBuf[:0]\n 228→\t\tcluster, host := clusterDefault, \"\"\n 229→\t\tfor {\n 230→\t\t\tkey, val, err := dec.NextTag()\n 231→\t\t\tif err != nil {\n 232→\t\t\t\treturn err\n 233→\t\t\t}\n 234→\t\t\tif key == nil {\n 235→\t\t\t\tbreak\n 236→\t\t\t}\n 237→\n 238→\t\t\t// The go compiler optimizes string([]byte{...}) == \"...\":\n 239→\t\t\tswitch string(key) {\n 240→\t\t\tcase \"cluster\":\n 241→\t\t\t\tif string(val) == prevCluster {\n 242→\t\t\t\t\tcluster = prevCluster\n 243→\t\t\t\t} else {\n 244→\t\t\t\t\tcluster = string(val)\n 245→\t\t\t\t\tlvl = nil\n 246→\t\t\t\t}\n 247→\t\t\tcase \"hostname\", \"host\":\n 248→\t\t\t\tif string(val) == prevHost {\n 249→\t\t\t\t\thost = prevHost\n 250→\t\t\t\t} else {\n 251→\t\t\t\t\thost = string(val)\n 252→\t\t\t\t\tlvl = nil\n 253→\t\t\t\t}\n 254→\t\t\tcase \"type\":\n 255→\t\t\t\tif string(val) == \"node\" {\n 256→\t\t\t\t\tbreak\n 257→\t\t\t\t}\n 258→\n 259→\t\t\t\t// We cannot be sure that the \"type\" tag comes before the \"type-id\" tag:\n 260→\t\t\t\tif len(st.typeBuf) == 0 {\n 261→\t\t\t\t\tst.typeBuf = append(st.typeBuf, val...)\n 262→\t\t\t\t} else {\n 263→\t\t\t\t\tst.typeBuf = reorder(st.typeBuf, val)\n 264→\t\t\t\t}\n 265→\t\t\tcase \"type-id\":\n 266→\t\t\t\tst.typeBuf = append(st.typeBuf, val...)\n 267→\t\t\tcase \"subtype\":\n 268→\t\t\t\t// We cannot be sure that the \"subtype\" tag comes before the \"stype-id\" tag:\n 269→\t\t\t\tif len(st.subTypeBuf) == 0 {\n 270→\t\t\t\t\tst.subTypeBuf = append(st.subTypeBuf, val...)\n 271→\t\t\t\t} else {\n 272→\t\t\t\t\tst.subTypeBuf = reorder(st.subTypeBuf, val)\n 273→\t\t\t\t}\n 274→\t\t\tcase \"stype-id\":\n 275→\t\t\t\tst.subTypeBuf = append(st.subTypeBuf, val...)\n 276→\t\t\tdefault:\n 277→\t\t\t}\n 278→\t\t}\n 279→\n 280→\t\t// If the cluster or host changed, the lvl was set to nil\n 281→\t\tif lvl == nil {\n 282→\t\t\tst.selector = st.selector[:2]\n 283→\t\t\tst.selector[0], st.selector[1] = cluster, host\n 284→\t\t\tlvl = ms.GetLevel(st.selector)\n 285→\t\t\tprevCluster, prevHost = cluster, host\n 286→\t\t}\n 287→\n 288→\t\t// subtypes: cache []byte→string conversions; messages in a batch typically\n 289→\t\t// share the same type/subtype so the hit rate is very high.\n 290→\t\tst.selector = st.selector[:0]\n 291→\t\tif len(st.typeBuf) > 0 {\n 292→\t\t\tif !bytes.Equal(st.typeBuf, st.prevTypeBytes) {\n 293→\t\t\t\tst.prevTypeBytes = append(st.prevTypeBytes[:0], st.typeBuf...)\n 294→\t\t\t\tst.prevTypeStr = string(st.typeBuf)\n 295→\t\t\t}\n 296→\t\t\tst.selector = append(st.selector, st.prevTypeStr)\n 297→\t\t\tif len(st.subTypeBuf) > 0 {\n 298→\t\t\t\tif !bytes.Equal(st.subTypeBuf, st.prevSubTypeBytes) {\n 299→\t\t\t\t\tst.prevSubTypeBytes = append(st.prevSubTypeBytes[:0], st.subTypeBuf...)\n 300→\t\t\t\t\tst.prevSubTypeStr = string(st.subTypeBuf)\n 301→\t\t\t\t}\n 302→\t\t\t\tst.selector = append(st.selector, st.prevSubTypeStr)\n 303→\t\t\t}\n 304→\t\t}\n 305→\n 306→\t\tfor {\n 307→\t\t\tkey, val, err := dec.NextField()\n 308→\t\t\tif err != nil {\n 309→\t\t\t\treturn err\n 310→\t\t\t}\n 311→\n 312→\t\t\tif key == nil {\n 313→\t\t\t\tbreak\n 314→\t\t\t}\n 315→\n 316→\t\t\tif string(key) != \"value\" {\n 317→\t\t\t\treturn fmt.Errorf(\"host %s: unknown field: '%s' (value: %#v)\", host, string(key), val)\n 318→\t\t\t}\n 319→\n 320→\t\t\tif val.Kind() == lineprotocol.Float {\n 321→\t\t\t\tmetric.Value = schema.Float(val.FloatV())\n 322→\t\t\t} else if val.Kind() == lineprotocol.Int {\n 323→\t\t\t\tmetric.Value = schema.Float(val.IntV())\n 324→\t\t\t} else if val.Kind() == lineprotocol.Uint {\n 325→\t\t\t\tmetric.Value = schema.Float(val.UintV())\n 326→\t\t\t} else {\n 327→\t\t\t\treturn fmt.Errorf(\"host %s: unsupported value type in message: %s\", host, val.Kind().String())\n 328→\t\t\t}\n 329→\t\t}\n 330→\n 331→\t\tif t, err = dec.Time(lineprotocol.Second, t); err != nil {\n 332→\t\t\tt = time.Now()\n 333→\t\t\tif t, err = dec.Time(lineprotocol.Millisecond, t); err != nil {\n 334→\t\t\t\tt = time.Now()\n 335→\t\t\t\tif t, err = dec.Time(lineprotocol.Microsecond, t); err != nil {\n 336→\t\t\t\t\tt = time.Now()\n 337→\t\t\t\t\tif t, err = dec.Time(lineprotocol.Nanosecond, t); err != nil {\n 338→\t\t\t\t\t\treturn fmt.Errorf(\"host %s: timestamp : %#v with error : %#v\", host, t, err.Error())\n 339→\t\t\t\t\t}\n 340→\t\t\t\t}\n 341→\t\t\t}\n 342→\t\t}\n 343→\n 344→\t\tif err != nil {\n 345→\t\t\treturn fmt.Errorf(\"host %s: timestamp : %#v with error : %#v\", host, t, err.Error())\n 346→\t\t}\n 347→\n 348→\t\ttime := t.Unix()\n 349→\n 350→\t\tif Keys.Checkpoints.FileFormat == \"wal\" {\n 351→\t\t\tWALMessages <- &WALMessage{\n 352→\t\t\t\tMetricName: string(st.metricBuf),\n 353→\t\t\t\tCluster: cluster,\n 354→\t\t\t\tNode: host,\n 355→\t\t\t\tSelector: append([]string{}, st.selector...),\n 356→\t\t\t\tValue: metric.Value,\n 357→\t\t\t\tTimestamp: time,\n 358→\t\t\t}\n 359→\t\t}\n 360→\n 361→\t\tif err := ms.WriteToLevel(lvl, st.selector, time, []Metric{metric}); err != nil {\n 362→\t\t\tcclog.Warnf(\"write error for host %s metric %s at ts %d: %s\", host, string(st.metricBuf), time, err.Error())\n 363→\t\t\tcontinue\n 364→\t\t}\n 365→\t}\n 366→\treturn nil\n 367→}\n 368→"}]},"uuid":"77dd8f5a-70ab-45e9-beeb-a01492815a92","timestamp":"2026-03-18T05:08:48.126Z","toolUseResult":{"type":"text","file":{"filePath":"/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/lineprotocol.go","content":"// Copyright (C) NHR@FAU, University Erlangen-Nuremberg.\n// All rights reserved. This file is part of cc-backend.\n// Use of this source code is governed by a MIT-style\n// license that can be found in the LICENSE file.\n\n// This file implements ingestion of InfluxDB line-protocol metric data received\n// over NATS. Each line encodes one metric sample with the following structure:\n//\n//\t[,cluster=][,hostname=][,type=][,type-id=][,subtype=][,stype-id=] value= []\n//\n// The measurement name identifies the metric (e.g. \"cpu_load\"). Tags provide\n// routing information (cluster, host) and optional sub-device selectors (type,\n// subtype). Only one field is expected per line: \"value\".\n//\n// After decoding, each sample is:\n// 1. Written to the in-memory store via ms.WriteToLevel.\n// 2. If the checkpoint format is \"wal\", also forwarded to the WAL staging\n// goroutine via the WALMessages channel for durable write-ahead logging.\npackage metricstore\n\nimport (\n\t\"bytes\"\n\t\"context\"\n\t\"fmt\"\n\t\"sync\"\n\t\"time\"\n\n\tcclog \"github.com/ClusterCockpit/cc-lib/v2/ccLogger\"\n\t\"github.com/ClusterCockpit/cc-lib/v2/nats\"\n\t\"github.com/ClusterCockpit/cc-lib/v2/schema\"\n\t\"github.com/ClusterCockpit/cc-line-protocol/v2/lineprotocol\"\n)\n\n// ReceiveNats subscribes to all configured NATS subjects and feeds incoming\n// line-protocol messages into the MemoryStore.\n//\n// When workers > 1 a pool of goroutines drains a shared channel so that\n// multiple messages can be decoded in parallel. With workers == 1 the NATS\n// callback decodes inline (no channel overhead, lower latency).\n//\n// The function blocks until ctx is cancelled and all worker goroutines have\n// finished. It returns nil when the NATS client is not configured; callers\n// should treat that as a no-op rather than an error.\nfunc ReceiveNats(ms *MemoryStore,\n\tworkers int,\n\tctx context.Context,\n) error {\n\tnc := nats.GetClient()\n\n\tif nc == nil {\n\t\tcclog.Warn(\"NATS client not initialized\")\n\t\treturn nil\n\t}\n\n\tvar wg sync.WaitGroup\n\tmsgs := make(chan []byte, workers*2)\n\n\tfor _, sc := range *Keys.Subscriptions {\n\t\tclusterTag := sc.ClusterTag\n\t\tif workers > 1 {\n\t\t\twg.Add(workers)\n\n\t\t\tfor range workers {\n\t\t\t\tgo func() {\n\t\t\t\t\tdefer wg.Done()\n\t\t\t\t\tfor m := range msgs {\n\t\t\t\t\t\tdec := lineprotocol.NewDecoderWithBytes(m)\n\t\t\t\t\t\tif err := DecodeLine(dec, ms, clusterTag); err != nil {\n\t\t\t\t\t\t\tcclog.Errorf(\"error: %s\", err.Error())\n\t\t\t\t\t\t}\n\t\t\t\t\t}\n\t\t\t\t}()\n\t\t\t}\n\n\t\t\tnc.Subscribe(sc.SubscribeTo, func(subject string, data []byte) {\n\t\t\t\tselect {\n\t\t\t\tcase msgs <- data:\n\t\t\t\tcase <-ctx.Done():\n\t\t\t\t}\n\t\t\t})\n\t\t} else {\n\t\t\tnc.Subscribe(sc.SubscribeTo, func(subject string, data []byte) {\n\t\t\t\tdec := lineprotocol.NewDecoderWithBytes(data)\n\t\t\t\tif err := DecodeLine(dec, ms, clusterTag); err != nil {\n\t\t\t\t\tcclog.Errorf(\"error: %s\", err.Error())\n\t\t\t\t}\n\t\t\t})\n\t\t}\n\t\tcclog.Infof(\"NATS subscription to '%s' established\", sc.SubscribeTo)\n\t}\n\n\tgo func() {\n\t\t<-ctx.Done()\n\t\tclose(msgs)\n\t}()\n\n\twg.Wait()\n\n\treturn nil\n}\n\n// reorder prepends prefix to buf in-place when buf has enough spare capacity,\n// avoiding an allocation. Falls back to a regular append otherwise.\n//\n// It is used to assemble the \"type\" and \"subtype\" selector\n// strings when the type tag arrives before the type-id tag in the line, so the\n// two byte slices need to be concatenated in tag-declaration order regardless\n// of wire order.\nfunc reorder(buf, prefix []byte) []byte {\n\tn := len(prefix)\n\tm := len(buf)\n\tif cap(buf) < m+n {\n\t\treturn append(prefix[:n:n], buf...)\n\t} else {\n\t\tbuf = buf[:n+m]\n\t\tfor i := m - 1; i >= 0; i-- {\n\t\t\tbuf[i+n] = buf[i]\n\t\t}\n\t\tfor i := range n {\n\t\t\tbuf[i] = prefix[i]\n\t\t}\n\t\treturn buf\n\t}\n}\n\n// decodeState holds the per-call scratch buffers used by DecodeLine.\n// Instances are recycled via decodeStatePool to avoid repeated allocations\n// during high-throughput ingestion.\ntype decodeState struct {\n\t// metricBuf holds a copy of the current measurement name (line-protocol\n\t// measurement field). Copied because dec.Measurement() returns a slice\n\t// that is invalidated by the next decoder call.\n\tmetricBuf []byte\n\n\t// selector is the sub-device path passed to WriteToLevel and WALMessage\n\t// (e.g. [\"socket0\"] or [\"socket0\", \"memctrl1\"]). Reused across lines.\n\tselector []string\n\n\t// typeBuf accumulates the concatenated \"type\"+\"type-id\" tag value for the\n\t// current line. Reset at the start of each line's tag-decode loop.\n\ttypeBuf []byte\n\n\t// subTypeBuf accumulates the concatenated \"subtype\"+\"stype-id\" tag value.\n\t// Reset at the start of each line's tag-decode loop.\n\tsubTypeBuf []byte\n\n\t// prevTypeBytes / prevTypeStr cache the last seen typeBuf content and its\n\t// string conversion. Because consecutive lines in a batch typically address\n\t// the same sub-device, the cache hit rate is very high and avoids\n\t// repeated []byte→string allocations.\n\tprevTypeBytes []byte\n\tprevTypeStr string\n\n\t// prevSubTypeBytes / prevSubTypeStr are the same cache for the subtype.\n\tprevSubTypeBytes []byte\n\tprevSubTypeStr string\n}\n\n// decodeStatePool recycles decodeState values across DecodeLine calls to\n// reduce GC pressure during sustained metric ingestion.\nvar decodeStatePool = sync.Pool{\n\tNew: func() any {\n\t\treturn &decodeState{\n\t\t\tmetricBuf: make([]byte, 0, 16),\n\t\t\tselector: make([]string, 0, 4),\n\t\t\ttypeBuf: make([]byte, 0, 16),\n\t\t\tsubTypeBuf: make([]byte, 0, 16),\n\t\t}\n\t},\n}\n\n// DecodeLine reads all lines from dec (InfluxDB line-protocol) and writes each\n// decoded metric sample into ms.\n//\n// clusterDefault is used as the cluster name for lines that do not carry a\n// \"cluster\" tag. Callers typically supply the ClusterTag value from the NATS\n// subscription configuration.\n//\n// Performance notes:\n// - A decodeState is obtained from decodeStatePool to reuse scratch buffers.\n// - The Level pointer (host-level node in the metric tree) is cached across\n// consecutive lines that share the same cluster+host pair to avoid\n// repeated lock acquisitions on the root and cluster levels.\n// - []byte→string conversions for type/subtype selectors are cached via\n// prevType*/prevSubType* fields because batches typically repeat the same\n// sub-device identifiers.\n// - Timestamp parsing tries Second precision first; if that fails it retries\n// Millisecond, Microsecond, and Nanosecond in turn. A missing timestamp\n// falls back to time.Now().\n//\n// When the checkpoint format is \"wal\" each successfully decoded sample is also\n// sent to WALMessages so the WAL staging goroutine can persist it durably\n// before the next binary snapshot.\nfunc DecodeLine(dec *lineprotocol.Decoder,\n\tms *MemoryStore,\n\tclusterDefault string,\n) error {\n\t// Reduce allocations in loop:\n\tt := time.Now()\n\tmetric := Metric{}\n\tst := decodeStatePool.Get().(*decodeState)\n\tdefer decodeStatePool.Put(st)\n\n\t// Optimize for the case where all lines in a \"batch\" are about the same\n\t// cluster and host. By using `WriteToLevel` (level = host), we do not need\n\t// to take the root- and cluster-level lock as often.\n\tvar lvl *Level = nil\n\tprevCluster, prevHost := \"\", \"\"\n\n\tvar ok bool\n\tfor dec.Next() {\n\t\trawmeasurement, err := dec.Measurement()\n\t\tif err != nil {\n\t\t\treturn err\n\t\t}\n\n\t\t// Needs to be copied because another call to dec.* would\n\t\t// invalidate the returned slice.\n\t\tst.metricBuf = append(st.metricBuf[:0], rawmeasurement...)\n\n\t\t// The go compiler optimizes map[string(byteslice)] lookups:\n\t\tmetric.MetricConfig, ok = ms.Metrics[string(rawmeasurement)]\n\t\tif !ok {\n\t\t\tcontinue\n\t\t}\n\n\t\tst.typeBuf, st.subTypeBuf = st.typeBuf[:0], st.subTypeBuf[:0]\n\t\tcluster, host := clusterDefault, \"\"\n\t\tfor {\n\t\t\tkey, val, err := dec.NextTag()\n\t\t\tif err != nil {\n\t\t\t\treturn err\n\t\t\t}\n\t\t\tif key == nil {\n\t\t\t\tbreak\n\t\t\t}\n\n\t\t\t// The go compiler optimizes string([]byte{...}) == \"...\":\n\t\t\tswitch string(key) {\n\t\t\tcase \"cluster\":\n\t\t\t\tif string(val) == prevCluster {\n\t\t\t\t\tcluster = prevCluster\n\t\t\t\t} else {\n\t\t\t\t\tcluster = string(val)\n\t\t\t\t\tlvl = nil\n\t\t\t\t}\n\t\t\tcase \"hostname\", \"host\":\n\t\t\t\tif string(val) == prevHost {\n\t\t\t\t\thost = prevHost\n\t\t\t\t} else {\n\t\t\t\t\thost = string(val)\n\t\t\t\t\tlvl = nil\n\t\t\t\t}\n\t\t\tcase \"type\":\n\t\t\t\tif string(val) == \"node\" {\n\t\t\t\t\tbreak\n\t\t\t\t}\n\n\t\t\t\t// We cannot be sure that the \"type\" tag comes before the \"type-id\" tag:\n\t\t\t\tif len(st.typeBuf) == 0 {\n\t\t\t\t\tst.typeBuf = append(st.typeBuf, val...)\n\t\t\t\t} else {\n\t\t\t\t\tst.typeBuf = reorder(st.typeBuf, val)\n\t\t\t\t}\n\t\t\tcase \"type-id\":\n\t\t\t\tst.typeBuf = append(st.typeBuf, val...)\n\t\t\tcase \"subtype\":\n\t\t\t\t// We cannot be sure that the \"subtype\" tag comes before the \"stype-id\" tag:\n\t\t\t\tif len(st.subTypeBuf) == 0 {\n\t\t\t\t\tst.subTypeBuf = append(st.subTypeBuf, val...)\n\t\t\t\t} else {\n\t\t\t\t\tst.subTypeBuf = reorder(st.subTypeBuf, val)\n\t\t\t\t}\n\t\t\tcase \"stype-id\":\n\t\t\t\tst.subTypeBuf = append(st.subTypeBuf, val...)\n\t\t\tdefault:\n\t\t\t}\n\t\t}\n\n\t\t// If the cluster or host changed, the lvl was set to nil\n\t\tif lvl == nil {\n\t\t\tst.selector = st.selector[:2]\n\t\t\tst.selector[0], st.selector[1] = cluster, host\n\t\t\tlvl = ms.GetLevel(st.selector)\n\t\t\tprevCluster, prevHost = cluster, host\n\t\t}\n\n\t\t// subtypes: cache []byte→string conversions; messages in a batch typically\n\t\t// share the same type/subtype so the hit rate is very high.\n\t\tst.selector = st.selector[:0]\n\t\tif len(st.typeBuf) > 0 {\n\t\t\tif !bytes.Equal(st.typeBuf, st.prevTypeBytes) {\n\t\t\t\tst.prevTypeBytes = append(st.prevTypeBytes[:0], st.typeBuf...)\n\t\t\t\tst.prevTypeStr = string(st.typeBuf)\n\t\t\t}\n\t\t\tst.selector = append(st.selector, st.prevTypeStr)\n\t\t\tif len(st.subTypeBuf) > 0 {\n\t\t\t\tif !bytes.Equal(st.subTypeBuf, st.prevSubTypeBytes) {\n\t\t\t\t\tst.prevSubTypeBytes = append(st.prevSubTypeBytes[:0], st.subTypeBuf...)\n\t\t\t\t\tst.prevSubTypeStr = string(st.subTypeBuf)\n\t\t\t\t}\n\t\t\t\tst.selector = append(st.selector, st.prevSubTypeStr)\n\t\t\t}\n\t\t}\n\n\t\tfor {\n\t\t\tkey, val, err := dec.NextField()\n\t\t\tif err != nil {\n\t\t\t\treturn err\n\t\t\t}\n\n\t\t\tif key == nil {\n\t\t\t\tbreak\n\t\t\t}\n\n\t\t\tif string(key) != \"value\" {\n\t\t\t\treturn fmt.Errorf(\"host %s: unknown field: '%s' (value: %#v)\", host, string(key), val)\n\t\t\t}\n\n\t\t\tif val.Kind() == lineprotocol.Float {\n\t\t\t\tmetric.Value = schema.Float(val.FloatV())\n\t\t\t} else if val.Kind() == lineprotocol.Int {\n\t\t\t\tmetric.Value = schema.Float(val.IntV())\n\t\t\t} else if val.Kind() == lineprotocol.Uint {\n\t\t\t\tmetric.Value = schema.Float(val.UintV())\n\t\t\t} else {\n\t\t\t\treturn fmt.Errorf(\"host %s: unsupported value type in message: %s\", host, val.Kind().String())\n\t\t\t}\n\t\t}\n\n\t\tif t, err = dec.Time(lineprotocol.Second, t); err != nil {\n\t\t\tt = time.Now()\n\t\t\tif t, err = dec.Time(lineprotocol.Millisecond, t); err != nil {\n\t\t\t\tt = time.Now()\n\t\t\t\tif t, err = dec.Time(lineprotocol.Microsecond, t); err != nil {\n\t\t\t\t\tt = time.Now()\n\t\t\t\t\tif t, err = dec.Time(lineprotocol.Nanosecond, t); err != nil {\n\t\t\t\t\t\treturn fmt.Errorf(\"host %s: timestamp : %#v with error : %#v\", host, t, err.Error())\n\t\t\t\t\t}\n\t\t\t\t}\n\t\t\t}\n\t\t}\n\n\t\tif err != nil {\n\t\t\treturn fmt.Errorf(\"host %s: timestamp : %#v with error : %#v\", host, t, err.Error())\n\t\t}\n\n\t\ttime := t.Unix()\n\n\t\tif Keys.Checkpoints.FileFormat == \"wal\" {\n\t\t\tWALMessages <- &WALMessage{\n\t\t\t\tMetricName: string(st.metricBuf),\n\t\t\t\tCluster: cluster,\n\t\t\t\tNode: host,\n\t\t\t\tSelector: append([]string{}, st.selector...),\n\t\t\t\tValue: metric.Value,\n\t\t\t\tTimestamp: time,\n\t\t\t}\n\t\t}\n\n\t\tif err := ms.WriteToLevel(lvl, st.selector, time, []Metric{metric}); err != nil {\n\t\t\tcclog.Warnf(\"write error for host %s metric %s at ts %d: %s\", host, string(st.metricBuf), time, err.Error())\n\t\t\tcontinue\n\t\t}\n\t}\n\treturn nil\n}\n","numLines":368,"startLine":1,"totalLines":368}},"sourceToolAssistantUUID":"75b19f05-5eda-4d82-857e-1b7885ece7ad","userType":"external","entrypoint":"cli","cwd":"/Users/jan/prg/ClusterCockpit/cc-backend","sessionId":"5eb20a94-f8df-4979-a0ae-2aa99bfad884","version":"2.1.78","gitBranch":"hotfix","slug":"bright-wandering-flurry"} +{"parentUuid":"77dd8f5a-70ab-45e9-beeb-a01492815a92","isSidechain":false,"message":{"model":"claude-opus-4-6","id":"msg_01FJM15SbFPE9emPyDSmVKXC","type":"message","role":"assistant","content":[{"type":"tool_use","id":"toolu_01ApoJH72VXMCPdcd7b9tZJo","name":"Read","input":{"file_path":"/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/walCheckpoint.go"},"caller":{"type":"direct"}}],"stop_reason":"tool_use","stop_sequence":null,"usage":{"input_tokens":3,"cache_creation_input_tokens":5791,"cache_read_input_tokens":14412,"output_tokens":251,"server_tool_use":{"web_search_requests":0,"web_fetch_requests":0},"service_tier":"standard","cache_creation":{"ephemeral_1h_input_tokens":5791,"ephemeral_5m_input_tokens":0},"inference_geo":"","iterations":[],"speed":"standard"}},"requestId":"req_011CZ9y59qXYvJaYQc65Pxx9","type":"assistant","uuid":"0f843ded-787a-4a2c-b5f2-64b7dcc395da","timestamp":"2026-03-18T05:08:48.243Z","userType":"external","entrypoint":"cli","cwd":"/Users/jan/prg/ClusterCockpit/cc-backend","sessionId":"5eb20a94-f8df-4979-a0ae-2aa99bfad884","version":"2.1.78","gitBranch":"hotfix","slug":"bright-wandering-flurry"} +{"parentUuid":"0f843ded-787a-4a2c-b5f2-64b7dcc395da","isSidechain":false,"type":"progress","data":{"type":"hook_progress","hookEvent":"PostToolUse","hookName":"PostToolUse:Read","command":"callback"},"parentToolUseID":"toolu_01ApoJH72VXMCPdcd7b9tZJo","toolUseID":"toolu_01ApoJH72VXMCPdcd7b9tZJo","timestamp":"2026-03-18T05:08:48.246Z","uuid":"fc6deb36-2f08-4830-8529-4d8b7de684b7","userType":"external","entrypoint":"cli","cwd":"/Users/jan/prg/ClusterCockpit/cc-backend","sessionId":"5eb20a94-f8df-4979-a0ae-2aa99bfad884","version":"2.1.78","gitBranch":"hotfix","slug":"bright-wandering-flurry"} +{"parentUuid":"0f843ded-787a-4a2c-b5f2-64b7dcc395da","isSidechain":false,"promptId":"6e6c2140-4cee-4dea-b053-88ef3746e514","type":"user","message":{"role":"user","content":[{"tool_use_id":"toolu_01ApoJH72VXMCPdcd7b9tZJo","type":"tool_result","content":" 1→// Copyright (C) NHR@FAU, University Erlangen-Nuremberg.\n 2→// All rights reserved. This file is part of cc-backend.\n 3→// Use of this source code is governed by a MIT-style\n 4→// license that can be found in the LICENSE file.\n 5→\n 6→// Package metricstore provides walCheckpoint.go: WAL-based checkpoint implementation.\n 7→//\n 8→// This replaces the Avro shadow tree with an append-only Write-Ahead Log (WAL)\n 9→// per host, eliminating the extra memory overhead of the AvroStore and providing\n 10→// truly continuous (per-write) crash safety.\n 11→//\n 12→// # Architecture\n 13→//\n 14→//\tMetric write (DecodeLine)\n 15→//\t │\n 16→//\t ├─► WriteToLevel() → main MemoryStore (unchanged)\n 17→//\t │\n 18→//\t └─► WALMessages channel\n 19→//\t │\n 20→//\t ▼\n 21→//\t WALStaging goroutine\n 22→//\t │\n 23→//\t ▼\n 24→//\t checkpoints/cluster/host/current.wal (append-only, binary)\n 25→//\n 26→//\tPeriodic checkpoint (Checkpointing goroutine):\n 27→//\t 1. Write .bin snapshot (column-oriented, from main tree)\n 28→//\t 2. Signal WALStaging to truncate current.wal per host\n 29→//\n 30→//\tOn restart (FromCheckpoint):\n 31→//\t 1. Load most recent .bin snapshot\n 32→//\t 2. Replay current.wal (overwrite-safe: buffer.write handles duplicate timestamps)\n 33→//\n 34→// # WAL Record Format\n 35→//\n 36→//\t[4B magic 0xCC1DA7A1][4B payload_len][payload][4B CRC32]\n 37→//\n 38→//\tpayload:\n 39→//\t [8B timestamp int64]\n 40→//\t [2B metric_name_len uint16][N metric name bytes]\n 41→//\t [1B selector_count uint8]\n 42→//\t per selector: [1B selector_len uint8][M selector bytes]\n 43→//\t [4B value float32 bits]\n 44→//\n 45→// # Binary Snapshot Format\n 46→//\n 47→//\t[4B magic 0xCC5B0001][8B from int64][8B to int64]\n 48→//\tLevel tree (recursive):\n 49→//\t [4B num_metrics uint32]\n 50→//\t per metric:\n 51→//\t [2B name_len uint16][N name bytes]\n 52→//\t [8B frequency int64][8B start int64]\n 53→//\t [4B num_values uint32][num_values × 4B float32]\n 54→//\t [4B num_children uint32]\n 55→//\t per child: [2B name_len uint16][N name bytes] + Level (recursive)\n 56→package metricstore\n 57→\n 58→import (\n 59→\t\"bufio\"\n 60→\t\"context\"\n 61→\t\"encoding/binary\"\n 62→\t\"fmt\"\n 63→\t\"hash/crc32\"\n 64→\t\"io\"\n 65→\t\"math\"\n 66→\t\"os\"\n 67→\t\"path\"\n 68→\t\"strings\"\n 69→\t\"sync\"\n 70→\t\"sync/atomic\"\n 71→\n 72→\tcclog \"github.com/ClusterCockpit/cc-lib/v2/ccLogger\"\n 73→\t\"github.com/ClusterCockpit/cc-lib/v2/schema\"\n 74→)\n 75→\n 76→// Magic numbers for binary formats.\n 77→const (\n 78→\twalFileMagic = uint32(0xCC1DA701) // WAL file header magic\n 79→\twalRecordMagic = uint32(0xCC1DA7A1) // WAL record magic\n 80→\tsnapFileMagic = uint32(0xCC5B0001) // Binary snapshot magic\n 81→)\n 82→\n 83→// WALMessages is the channel for sending metric writes to the WAL staging goroutine.\n 84→// Buffered to allow burst writes without blocking the metric ingestion path.\n 85→var WALMessages = make(chan *WALMessage, 4096)\n 86→\n 87→// walRotateCh is used by the checkpoint goroutine to request WAL file rotation\n 88→// (close, delete, reopen) after a binary snapshot has been written.\n 89→var walRotateCh = make(chan walRotateReq, 256)\n 90→\n 91→// WALMessage represents a single metric write to be appended to the WAL.\n 92→// Cluster and Node are NOT stored in the WAL record (inferred from file path).\n 93→type WALMessage struct {\n 94→\tMetricName string\n 95→\tCluster string\n 96→\tNode string\n 97→\tSelector []string\n 98→\tValue schema.Float\n 99→\tTimestamp int64\n 100→}\n 101→\n 102→// walRotateReq requests WAL file rotation for a specific host directory.\n 103→// The done channel is closed by the WAL goroutine when rotation is complete.\n 104→type walRotateReq struct {\n 105→\thostDir string\n 106→\tdone chan struct{}\n 107→}\n 108→\n 109→// walFileState holds an open WAL file handle and buffered writer for one host directory.\n 110→type walFileState struct {\n 111→\tf *os.File\n 112→\tw *bufio.Writer\n 113→}\n 114→\n 115→// WALStaging starts a background goroutine that receives WALMessage items\n 116→// and appends binary WAL records to per-host current.wal files.\n 117→// Also handles WAL rotation requests from the checkpoint goroutine.\n 118→func WALStaging(wg *sync.WaitGroup, ctx context.Context) {\n 119→\twg.Go(func() {\n 120→\t\tif Keys.Checkpoints.FileFormat == \"json\" {\n 121→\t\t\treturn\n 122→\t\t}\n 123→\n 124→\t\thostFiles := make(map[string]*walFileState)\n 125→\n 126→\t\tdefer func() {\n 127→\t\t\tfor _, ws := range hostFiles {\n 128→\t\t\t\tif ws.f != nil {\n 129→\t\t\t\t\tws.w.Flush()\n 130→\t\t\t\t\tws.f.Close()\n 131→\t\t\t\t}\n 132→\t\t\t}\n 133→\t\t}()\n 134→\n 135→\t\tgetOrOpenWAL := func(hostDir string) *walFileState {\n 136→\t\t\tws, ok := hostFiles[hostDir]\n 137→\t\t\tif ok {\n 138→\t\t\t\treturn ws\n 139→\t\t\t}\n 140→\n 141→\t\t\tif err := os.MkdirAll(hostDir, CheckpointDirPerms); err != nil {\n 142→\t\t\t\tcclog.Errorf(\"[METRICSTORE]> WAL: mkdir %s: %v\", hostDir, err)\n 143→\t\t\t\treturn nil\n 144→\t\t\t}\n 145→\n 146→\t\t\twalPath := path.Join(hostDir, \"current.wal\")\n 147→\t\t\tf, err := os.OpenFile(walPath, os.O_CREATE|os.O_APPEND|os.O_WRONLY, CheckpointFilePerms)\n 148→\t\t\tif err != nil {\n 149→\t\t\t\tcclog.Errorf(\"[METRICSTORE]> WAL: open %s: %v\", walPath, err)\n 150→\t\t\t\treturn nil\n 151→\t\t\t}\n 152→\n 153→\t\t\tw := bufio.NewWriter(f)\n 154→\n 155→\t\t\t// Write file header magic if file is new (empty).\n 156→\t\t\tinfo, err := f.Stat()\n 157→\t\t\tif err == nil && info.Size() == 0 {\n 158→\t\t\t\tvar hdr [4]byte\n 159→\t\t\t\tbinary.LittleEndian.PutUint32(hdr[:], walFileMagic)\n 160→\t\t\t\tif _, err := w.Write(hdr[:]); err != nil {\n 161→\t\t\t\t\tcclog.Errorf(\"[METRICSTORE]> WAL: write header %s: %v\", walPath, err)\n 162→\t\t\t\t\tf.Close()\n 163→\t\t\t\t\treturn nil\n 164→\t\t\t\t}\n 165→\t\t\t}\n 166→\n 167→\t\t\tws = &walFileState{f: f, w: w}\n 168→\t\t\thostFiles[hostDir] = ws\n 169→\t\t\treturn ws\n 170→\t\t}\n 171→\n 172→\t\tprocessMsg := func(msg *WALMessage) {\n 173→\t\t\thostDir := path.Join(Keys.Checkpoints.RootDir, msg.Cluster, msg.Node)\n 174→\t\t\tws := getOrOpenWAL(hostDir)\n 175→\t\t\tif ws == nil {\n 176→\t\t\t\treturn\n 177→\t\t\t}\n 178→\t\t\tif err := writeWALRecord(ws.w, msg); err != nil {\n 179→\t\t\t\tcclog.Errorf(\"[METRICSTORE]> WAL: write record: %v\", err)\n 180→\t\t\t}\n 181→\t\t}\n 182→\n 183→\t\tprocessRotate := func(req walRotateReq) {\n 184→\t\t\tws, ok := hostFiles[req.hostDir]\n 185→\t\t\tif ok && ws.f != nil {\n 186→\t\t\t\tws.w.Flush()\n 187→\t\t\t\tws.f.Close()\n 188→\t\t\t\twalPath := path.Join(req.hostDir, \"current.wal\")\n 189→\t\t\t\tif err := os.Remove(walPath); err != nil && !os.IsNotExist(err) {\n 190→\t\t\t\t\tcclog.Errorf(\"[METRICSTORE]> WAL: remove %s: %v\", walPath, err)\n 191→\t\t\t\t}\n 192→\t\t\t\tdelete(hostFiles, req.hostDir)\n 193→\t\t\t}\n 194→\t\t\tclose(req.done)\n 195→\t\t}\n 196→\n 197→\t\tdrain := func() {\n 198→\t\t\tfor {\n 199→\t\t\t\tselect {\n 200→\t\t\t\tcase msg, ok := <-WALMessages:\n 201→\t\t\t\t\tif !ok {\n 202→\t\t\t\t\t\treturn\n 203→\t\t\t\t\t}\n 204→\t\t\t\t\tprocessMsg(msg)\n 205→\t\t\t\tcase req := <-walRotateCh:\n 206→\t\t\t\t\tprocessRotate(req)\n 207→\t\t\t\tdefault:\n 208→\t\t\t\t\t// Flush all buffered writers after draining remaining messages.\n 209→\t\t\t\t\tfor _, ws := range hostFiles {\n 210→\t\t\t\t\t\tif ws.f != nil {\n 211→\t\t\t\t\t\t\tws.w.Flush()\n 212→\t\t\t\t\t\t}\n 213→\t\t\t\t\t}\n 214→\t\t\t\t\treturn\n 215→\t\t\t\t}\n 216→\t\t\t}\n 217→\t\t}\n 218→\n 219→\t\tfor {\n 220→\t\t\tselect {\n 221→\t\t\tcase <-ctx.Done():\n 222→\t\t\t\tdrain()\n 223→\t\t\t\treturn\n 224→\t\t\tcase msg, ok := <-WALMessages:\n 225→\t\t\t\tif !ok {\n 226→\t\t\t\t\treturn\n 227→\t\t\t\t}\n 228→\t\t\t\tprocessMsg(msg)\n 229→\t\t\tcase req := <-walRotateCh:\n 230→\t\t\t\tprocessRotate(req)\n 231→\t\t\t}\n 232→\t\t}\n 233→\t})\n 234→}\n 235→\n 236→// RotateWALFiles sends rotation requests for the given host directories\n 237→// and blocks until all rotations complete.\n 238→func RotateWALFiles(hostDirs []string) {\n 239→\tdones := make([]chan struct{}, len(hostDirs))\n 240→\tfor i, dir := range hostDirs {\n 241→\t\tdones[i] = make(chan struct{})\n 242→\t\twalRotateCh <- walRotateReq{hostDir: dir, done: dones[i]}\n 243→\t}\n 244→\tfor _, done := range dones {\n 245→\t\t<-done\n 246→\t}\n 247→}\n 248→\n 249→// RotateWALFiles sends rotation requests for the given host directories\n 250→// and blocks until all rotations complete.\n 251→func RotateWALFilesAfterShutdown(hostDirs []string) {\n 252→\tfor _, dir := range hostDirs {\n 253→\t\twalPath := path.Join(dir, \"current.wal\")\n 254→\t\tif err := os.Remove(walPath); err != nil && !os.IsNotExist(err) {\n 255→\t\t\tcclog.Errorf(\"[METRICSTORE]> WAL: remove %s: %v\", walPath, err)\n 256→\t\t}\n 257→\t}\n 258→}\n 259→\n 260→// buildWALPayload encodes a WALMessage into a binary payload (without magic/length/CRC).\n 261→func buildWALPayload(msg *WALMessage) []byte {\n 262→\tsize := 8 + 2 + len(msg.MetricName) + 1 + 4\n 263→\tfor _, s := range msg.Selector {\n 264→\t\tsize += 1 + len(s)\n 265→\t}\n 266→\n 267→\tbuf := make([]byte, 0, size)\n 268→\n 269→\t// Timestamp (8 bytes, little-endian int64)\n 270→\tvar ts [8]byte\n 271→\tbinary.LittleEndian.PutUint64(ts[:], uint64(msg.Timestamp))\n 272→\tbuf = append(buf, ts[:]...)\n 273→\n 274→\t// Metric name (2-byte length prefix + bytes)\n 275→\tvar mLen [2]byte\n 276→\tbinary.LittleEndian.PutUint16(mLen[:], uint16(len(msg.MetricName)))\n 277→\tbuf = append(buf, mLen[:]...)\n 278→\tbuf = append(buf, msg.MetricName...)\n 279→\n 280→\t// Selector count (1 byte)\n 281→\tbuf = append(buf, byte(len(msg.Selector)))\n 282→\n 283→\t// Selectors (1-byte length prefix + bytes each)\n 284→\tfor _, sel := range msg.Selector {\n 285→\t\tbuf = append(buf, byte(len(sel)))\n 286→\t\tbuf = append(buf, sel...)\n 287→\t}\n 288→\n 289→\t// Value (4 bytes, float32 bit representation)\n 290→\tvar val [4]byte\n 291→\tbinary.LittleEndian.PutUint32(val[:], math.Float32bits(float32(msg.Value)))\n 292→\tbuf = append(buf, val[:]...)\n 293→\n 294→\treturn buf\n 295→}\n 296→\n 297→// writeWALRecord appends a binary WAL record to the writer.\n 298→// Format: [4B magic][4B payload_len][payload][4B CRC32]\n 299→func writeWALRecord(w io.Writer, msg *WALMessage) error {\n 300→\tpayload := buildWALPayload(msg)\n 301→\tcrc := crc32.ChecksumIEEE(payload)\n 302→\n 303→\trecord := make([]byte, 0, 4+4+len(payload)+4)\n 304→\n 305→\tvar magic [4]byte\n 306→\tbinary.LittleEndian.PutUint32(magic[:], walRecordMagic)\n 307→\trecord = append(record, magic[:]...)\n 308→\n 309→\tvar pLen [4]byte\n 310→\tbinary.LittleEndian.PutUint32(pLen[:], uint32(len(payload)))\n 311→\trecord = append(record, pLen[:]...)\n 312→\n 313→\trecord = append(record, payload...)\n 314→\n 315→\tvar crcBytes [4]byte\n 316→\tbinary.LittleEndian.PutUint32(crcBytes[:], crc)\n 317→\trecord = append(record, crcBytes[:]...)\n 318→\n 319→\t_, err := w.Write(record)\n 320→\treturn err\n 321→}\n 322→\n 323→// readWALRecord reads one WAL record from the reader.\n 324→// Returns (nil, nil) on clean EOF. Returns error on data corruption.\n 325→// A CRC mismatch indicates a truncated trailing record (expected on crash).\n 326→func readWALRecord(r io.Reader) (*WALMessage, error) {\n 327→\tvar magic uint32\n 328→\tif err := binary.Read(r, binary.LittleEndian, &magic); err != nil {\n 329→\t\tif err == io.EOF {\n 330→\t\t\treturn nil, nil // Clean EOF\n 331→\t\t}\n 332→\t\treturn nil, fmt.Errorf(\"read record magic: %w\", err)\n 333→\t}\n 334→\n 335→\tif magic != walRecordMagic {\n 336→\t\treturn nil, fmt.Errorf(\"invalid record magic 0x%08X (expected 0x%08X)\", magic, walRecordMagic)\n 337→\t}\n 338→\n 339→\tvar payloadLen uint32\n 340→\tif err := binary.Read(r, binary.LittleEndian, &payloadLen); err != nil {\n 341→\t\treturn nil, fmt.Errorf(\"read payload length: %w\", err)\n 342→\t}\n 343→\n 344→\tif payloadLen > 1<<20 { // 1 MB sanity limit\n 345→\t\treturn nil, fmt.Errorf(\"record payload too large: %d bytes\", payloadLen)\n 346→\t}\n 347→\n 348→\tpayload := make([]byte, payloadLen)\n 349→\tif _, err := io.ReadFull(r, payload); err != nil {\n 350→\t\treturn nil, fmt.Errorf(\"read payload: %w\", err)\n 351→\t}\n 352→\n 353→\tvar storedCRC uint32\n 354→\tif err := binary.Read(r, binary.LittleEndian, &storedCRC); err != nil {\n 355→\t\treturn nil, fmt.Errorf(\"read CRC: %w\", err)\n 356→\t}\n 357→\n 358→\tif crc32.ChecksumIEEE(payload) != storedCRC {\n 359→\t\treturn nil, fmt.Errorf(\"CRC mismatch (truncated write or corruption)\")\n 360→\t}\n 361→\n 362→\treturn parseWALPayload(payload)\n 363→}\n 364→\n 365→// parseWALPayload decodes a binary payload into a WALMessage.\n 366→func parseWALPayload(payload []byte) (*WALMessage, error) {\n 367→\tif len(payload) < 8+2+1+4 {\n 368→\t\treturn nil, fmt.Errorf(\"payload too short: %d bytes\", len(payload))\n 369→\t}\n 370→\n 371→\toffset := 0\n 372→\n 373→\t// Timestamp (8 bytes)\n 374→\tts := int64(binary.LittleEndian.Uint64(payload[offset : offset+8]))\n 375→\toffset += 8\n 376→\n 377→\t// Metric name (2-byte length + bytes)\n 378→\tif offset+2 > len(payload) {\n 379→\t\treturn nil, fmt.Errorf(\"metric name length overflows payload\")\n 380→\t}\n 381→\tmLen := int(binary.LittleEndian.Uint16(payload[offset : offset+2]))\n 382→\toffset += 2\n 383→\n 384→\tif offset+mLen > len(payload) {\n 385→\t\treturn nil, fmt.Errorf(\"metric name overflows payload\")\n 386→\t}\n 387→\tmetricName := string(payload[offset : offset+mLen])\n 388→\toffset += mLen\n 389→\n 390→\t// Selector count (1 byte)\n 391→\tif offset >= len(payload) {\n 392→\t\treturn nil, fmt.Errorf(\"selector count overflows payload\")\n 393→\t}\n 394→\tselCount := int(payload[offset])\n 395→\toffset++\n 396→\n 397→\tselectors := make([]string, selCount)\n 398→\tfor i := range selCount {\n 399→\t\tif offset >= len(payload) {\n 400→\t\t\treturn nil, fmt.Errorf(\"selector[%d] length overflows payload\", i)\n 401→\t\t}\n 402→\t\tsLen := int(payload[offset])\n 403→\t\toffset++\n 404→\n 405→\t\tif offset+sLen > len(payload) {\n 406→\t\t\treturn nil, fmt.Errorf(\"selector[%d] data overflows payload\", i)\n 407→\t\t}\n 408→\t\tselectors[i] = string(payload[offset : offset+sLen])\n 409→\t\toffset += sLen\n 410→\t}\n 411→\n 412→\t// Value (4 bytes, float32 bits)\n 413→\tif offset+4 > len(payload) {\n 414→\t\treturn nil, fmt.Errorf(\"value overflows payload\")\n 415→\t}\n 416→\tbits := binary.LittleEndian.Uint32(payload[offset : offset+4])\n 417→\tvalue := schema.Float(math.Float32frombits(bits))\n 418→\n 419→\treturn &WALMessage{\n 420→\t\tMetricName: metricName,\n 421→\t\tTimestamp: ts,\n 422→\t\tSelector: selectors,\n 423→\t\tValue: value,\n 424→\t}, nil\n 425→}\n 426→\n 427→// loadWALFile reads a WAL file and replays all valid records into the Level tree.\n 428→// l is the host-level node. Corrupt or partial trailing records are silently skipped\n 429→// (expected on crash). Records older than 'from' are skipped.\n 430→func (l *Level) loadWALFile(m *MemoryStore, f *os.File, from int64) error {\n 431→\tbr := bufio.NewReader(f)\n 432→\n 433→\t// Verify file header magic.\n 434→\tvar fileMagic uint32\n 435→\tif err := binary.Read(br, binary.LittleEndian, &fileMagic); err != nil {\n 436→\t\tif err == io.EOF {\n 437→\t\t\treturn nil // Empty file, no data\n 438→\t\t}\n 439→\t\treturn fmt.Errorf(\"[METRICSTORE]> WAL: read file header: %w\", err)\n 440→\t}\n 441→\n 442→\tif fileMagic != walFileMagic {\n 443→\t\treturn fmt.Errorf(\"[METRICSTORE]> WAL: invalid file magic 0x%08X (expected 0x%08X)\", fileMagic, walFileMagic)\n 444→\t}\n 445→\n 446→\t// Cache level lookups to avoid repeated tree traversal.\n 447→\tlvlCache := make(map[string]*Level)\n 448→\n 449→\tfor {\n 450→\t\tmsg, err := readWALRecord(br)\n 451→\t\tif err != nil {\n 452→\t\t\t// Truncated trailing record is expected after a crash; stop replaying.\n 453→\t\t\tcclog.Debugf(\"[METRICSTORE]> WAL: stopping replay at corrupted/partial record: %v\", err)\n 454→\t\t\tbreak\n 455→\t\t}\n 456→\t\tif msg == nil {\n 457→\t\t\tbreak // Clean EOF\n 458→\t\t}\n 459→\n 460→\t\tif msg.Timestamp < from {\n 461→\t\t\tcontinue // Older than retention window\n 462→\t\t}\n 463→\n 464→\t\tminfo, ok := m.Metrics[msg.MetricName]\n 465→\t\tif !ok {\n 466→\t\t\tcontinue // Unknown metric (config may have changed)\n 467→\t\t}\n 468→\n 469→\t\t// Cache key is the null-separated selector path.\n 470→\t\tcacheKey := joinSelector(msg.Selector)\n 471→\t\tlvl, ok := lvlCache[cacheKey]\n 472→\t\tif !ok {\n 473→\t\t\tlvl = l.findLevelOrCreate(msg.Selector, len(m.Metrics))\n 474→\t\t\tlvlCache[cacheKey] = lvl\n 475→\t\t}\n 476→\n 477→\t\t// Write directly to the buffer, same as WriteToLevel but without the\n 478→\t\t// global level lookup (we already have the right level).\n 479→\t\tlvl.lock.Lock()\n 480→\t\tb := lvl.metrics[minfo.offset]\n 481→\t\tif b == nil {\n 482→\t\t\tb = newBuffer(msg.Timestamp, minfo.Frequency)\n 483→\t\t\tlvl.metrics[minfo.offset] = b\n 484→\t\t}\n 485→\t\tnb, writeErr := b.write(msg.Timestamp, msg.Value)\n 486→\t\tif writeErr == nil && b != nb {\n 487→\t\t\tlvl.metrics[minfo.offset] = nb\n 488→\t\t}\n 489→\t\t// Ignore write errors for timestamps before buffer start (can happen when\n 490→\t\t// replaying WAL entries that predate a loaded snapshot's start time).\n 491→\t\tlvl.lock.Unlock()\n 492→\t}\n 493→\n 494→\treturn nil\n 495→}\n 496→\n 497→// joinSelector builds a cache key from a selector slice using null bytes as separators.\n 498→func joinSelector(sel []string) string {\n 499→\tif len(sel) == 0 {\n 500→\t\treturn \"\"\n 501→\t}\n 502→\tvar result strings.Builder\n 503→\tresult.WriteString(sel[0])\n 504→\tfor i := 1; i < len(sel); i++ {\n 505→\t\tresult.WriteString(\"\\x00\" + sel[i])\n 506→\t}\n 507→\treturn result.String()\n 508→}\n 509→\n 510→// ToCheckpointWAL writes binary snapshot files for all hosts in parallel.\n 511→// Returns the number of files written, the list of host directories that were\n 512→// successfully checkpointed (for WAL rotation), and any errors.\n 513→func (m *MemoryStore) ToCheckpointWAL(dir string, from, to int64) (int, []string, error) {\n 514→\t// Collect all cluster/host pairs.\n 515→\tm.root.lock.RLock()\n 516→\ttotalHosts := 0\n 517→\tfor _, l1 := range m.root.children {\n 518→\t\tl1.lock.RLock()\n 519→\t\ttotalHosts += len(l1.children)\n 520→\t\tl1.lock.RUnlock()\n 521→\t}\n 522→\tm.root.lock.RUnlock()\n 523→\n 524→\tlevels := make([]*Level, 0, totalHosts)\n 525→\tselectors := make([][]string, 0, totalHosts)\n 526→\n 527→\tm.root.lock.RLock()\n 528→\tfor sel1, l1 := range m.root.children {\n 529→\t\tl1.lock.RLock()\n 530→\t\tfor sel2, l2 := range l1.children {\n 531→\t\t\tlevels = append(levels, l2)\n 532→\t\t\tselectors = append(selectors, []string{sel1, sel2})\n 533→\t\t}\n 534→\t\tl1.lock.RUnlock()\n 535→\t}\n 536→\tm.root.lock.RUnlock()\n 537→\n 538→\ttype workItem struct {\n 539→\t\tlevel *Level\n 540→\t\thostDir string\n 541→\t\tselector []string\n 542→\t}\n 543→\n 544→\tn, errs := int32(0), int32(0)\n 545→\tvar successDirs []string\n 546→\tvar successMu sync.Mutex\n 547→\n 548→\tvar wg sync.WaitGroup\n 549→\twg.Add(Keys.NumWorkers)\n 550→\twork := make(chan workItem, Keys.NumWorkers*2)\n 551→\n 552→\tfor range Keys.NumWorkers {\n 553→\t\tgo func() {\n 554→\t\t\tdefer wg.Done()\n 555→\t\t\tfor wi := range work {\n 556→\t\t\t\terr := wi.level.toCheckpointBinary(wi.hostDir, from, to, m)\n 557→\t\t\t\tif err != nil {\n 558→\t\t\t\t\tif err == ErrNoNewArchiveData {\n 559→\t\t\t\t\t\tcontinue\n 560→\t\t\t\t\t}\n 561→\t\t\t\t\tcclog.Errorf(\"[METRICSTORE]> binary checkpoint error for %s: %v\", wi.hostDir, err)\n 562→\t\t\t\t\tatomic.AddInt32(&errs, 1)\n 563→\t\t\t\t} else {\n 564→\t\t\t\t\tatomic.AddInt32(&n, 1)\n 565→\t\t\t\t\tsuccessMu.Lock()\n 566→\t\t\t\t\tsuccessDirs = append(successDirs, wi.hostDir)\n 567→\t\t\t\t\tsuccessMu.Unlock()\n 568→\t\t\t\t}\n 569→\t\t\t}\n 570→\t\t}()\n 571→\t}\n 572→\n 573→\tfor i := range levels {\n 574→\t\thostDir := path.Join(dir, path.Join(selectors[i]...))\n 575→\t\twork <- workItem{\n 576→\t\t\tlevel: levels[i],\n 577→\t\t\thostDir: hostDir,\n 578→\t\t\tselector: selectors[i],\n 579→\t\t}\n 580→\t}\n 581→\tclose(work)\n 582→\twg.Wait()\n 583→\n 584→\tif errs > 0 {\n 585→\t\treturn int(n), successDirs, fmt.Errorf(\"[METRICSTORE]> %d errors during binary checkpoint (%d successes)\", errs, n)\n 586→\t}\n 587→\treturn int(n), successDirs, nil\n 588→}\n 589→\n 590→// toCheckpointBinary writes a binary snapshot file for a single host-level node.\n 591→// Uses atomic rename (write to .tmp then rename) to avoid partial reads on crash.\n 592→func (l *Level) toCheckpointBinary(dir string, from, to int64, m *MemoryStore) error {\n 593→\tcf, err := l.toCheckpointFile(from, to, m)\n 594→\tif err != nil {\n 595→\t\treturn err\n 596→\t}\n 597→\tif cf == nil {\n 598→\t\treturn ErrNoNewArchiveData\n 599→\t}\n 600→\n 601→\tif err := os.MkdirAll(dir, CheckpointDirPerms); err != nil {\n 602→\t\treturn fmt.Errorf(\"mkdir %s: %w\", dir, err)\n 603→\t}\n 604→\n 605→\t// Write to a temp file first, then rename (atomic on POSIX).\n 606→\ttmpPath := path.Join(dir, fmt.Sprintf(\"%d.bin.tmp\", from))\n 607→\tfinalPath := path.Join(dir, fmt.Sprintf(\"%d.bin\", from))\n 608→\n 609→\tf, err := os.OpenFile(tmpPath, os.O_CREATE|os.O_WRONLY|os.O_TRUNC, CheckpointFilePerms)\n 610→\tif err != nil {\n 611→\t\treturn fmt.Errorf(\"open binary snapshot %s: %w\", tmpPath, err)\n 612→\t}\n 613→\n 614→\tbw := bufio.NewWriter(f)\n 615→\tif err := writeBinarySnapshotFile(bw, cf); err != nil {\n 616→\t\tf.Close()\n 617→\t\tos.Remove(tmpPath)\n 618→\t\treturn fmt.Errorf(\"write binary snapshot: %w\", err)\n 619→\t}\n 620→\tif err := bw.Flush(); err != nil {\n 621→\t\tf.Close()\n 622→\t\tos.Remove(tmpPath)\n 623→\t\treturn err\n 624→\t}\n 625→\tf.Close()\n 626→\n 627→\treturn os.Rename(tmpPath, finalPath)\n 628→}\n 629→\n 630→// writeBinarySnapshotFile writes the binary snapshot file header and level tree.\n 631→func writeBinarySnapshotFile(w io.Writer, cf *CheckpointFile) error {\n 632→\tif err := binary.Write(w, binary.LittleEndian, snapFileMagic); err != nil {\n 633→\t\treturn err\n 634→\t}\n 635→\tif err := binary.Write(w, binary.LittleEndian, cf.From); err != nil {\n 636→\t\treturn err\n 637→\t}\n 638→\tif err := binary.Write(w, binary.LittleEndian, cf.To); err != nil {\n 639→\t\treturn err\n 640→\t}\n 641→\treturn writeBinaryLevel(w, cf)\n 642→}\n 643→\n 644→// writeBinaryLevel recursively writes a CheckpointFile level in binary format.\n 645→func writeBinaryLevel(w io.Writer, cf *CheckpointFile) error {\n 646→\tif err := binary.Write(w, binary.LittleEndian, uint32(len(cf.Metrics))); err != nil {\n 647→\t\treturn err\n 648→\t}\n 649→\n 650→\tfor name, metric := range cf.Metrics {\n 651→\t\tif err := writeString16(w, name); err != nil {\n 652→\t\t\treturn err\n 653→\t\t}\n 654→\t\tif err := binary.Write(w, binary.LittleEndian, metric.Frequency); err != nil {\n 655→\t\t\treturn err\n 656→\t\t}\n 657→\t\tif err := binary.Write(w, binary.LittleEndian, metric.Start); err != nil {\n 658→\t\t\treturn err\n 659→\t\t}\n 660→\t\tif err := binary.Write(w, binary.LittleEndian, uint32(len(metric.Data))); err != nil {\n 661→\t\t\treturn err\n 662→\t\t}\n 663→\t\tfor _, v := range metric.Data {\n 664→\t\t\tif err := binary.Write(w, binary.LittleEndian, math.Float32bits(float32(v))); err != nil {\n 665→\t\t\t\treturn err\n 666→\t\t\t}\n 667→\t\t}\n 668→\t}\n 669→\n 670→\tif err := binary.Write(w, binary.LittleEndian, uint32(len(cf.Children))); err != nil {\n 671→\t\treturn err\n 672→\t}\n 673→\n 674→\tfor name, child := range cf.Children {\n 675→\t\tif err := writeString16(w, name); err != nil {\n 676→\t\t\treturn err\n 677→\t\t}\n 678→\t\tif err := writeBinaryLevel(w, child); err != nil {\n 679→\t\t\treturn err\n 680→\t\t}\n 681→\t}\n 682→\n 683→\treturn nil\n 684→}\n 685→\n 686→// writeString16 writes a 2-byte length-prefixed string to w.\n 687→func writeString16(w io.Writer, s string) error {\n 688→\tif err := binary.Write(w, binary.LittleEndian, uint16(len(s))); err != nil {\n 689→\t\treturn err\n 690→\t}\n 691→\t_, err := io.WriteString(w, s)\n 692→\treturn err\n 693→}\n 694→\n 695→// loadBinaryFile reads a binary snapshot file and loads data into the Level tree.\n 696→// The retention check (from) is applied to the file's 'to' timestamp.\n 697→func (l *Level) loadBinaryFile(m *MemoryStore, f *os.File, from int64) error {\n 698→\tbr := bufio.NewReader(f)\n 699→\n 700→\tvar magic uint32\n 701→\tif err := binary.Read(br, binary.LittleEndian, &magic); err != nil {\n 702→\t\treturn fmt.Errorf(\"[METRICSTORE]> binary snapshot: read magic: %w\", err)\n 703→\t}\n 704→\tif magic != snapFileMagic {\n 705→\t\treturn fmt.Errorf(\"[METRICSTORE]> binary snapshot: invalid magic 0x%08X (expected 0x%08X)\", magic, snapFileMagic)\n 706→\t}\n 707→\n 708→\tvar fileFrom, fileTo int64\n 709→\tif err := binary.Read(br, binary.LittleEndian, &fileFrom); err != nil {\n 710→\t\treturn fmt.Errorf(\"[METRICSTORE]> binary snapshot: read from: %w\", err)\n 711→\t}\n 712→\tif err := binary.Read(br, binary.LittleEndian, &fileTo); err != nil {\n 713→\t\treturn fmt.Errorf(\"[METRICSTORE]> binary snapshot: read to: %w\", err)\n 714→\t}\n 715→\n 716→\tif fileTo != 0 && fileTo < from {\n 717→\t\treturn nil // File is older than retention window, skip it\n 718→\t}\n 719→\n 720→\tcf, err := readBinaryLevel(br)\n 721→\tif err != nil {\n 722→\t\treturn fmt.Errorf(\"[METRICSTORE]> binary snapshot: read level tree: %w\", err)\n 723→\t}\n 724→\tcf.From = fileFrom\n 725→\tcf.To = fileTo\n 726→\n 727→\treturn l.loadFile(cf, m)\n 728→}\n 729→\n 730→// readBinaryLevel recursively reads a level from the binary snapshot format.\n 731→func readBinaryLevel(r io.Reader) (*CheckpointFile, error) {\n 732→\tcf := &CheckpointFile{\n 733→\t\tMetrics: make(map[string]*CheckpointMetrics),\n 734→\t\tChildren: make(map[string]*CheckpointFile),\n 735→\t}\n 736→\n 737→\tvar numMetrics uint32\n 738→\tif err := binary.Read(r, binary.LittleEndian, &numMetrics); err != nil {\n 739→\t\treturn nil, fmt.Errorf(\"read num_metrics: %w\", err)\n 740→\t}\n 741→\n 742→\tfor range numMetrics {\n 743→\t\tname, err := readString16(r)\n 744→\t\tif err != nil {\n 745→\t\t\treturn nil, fmt.Errorf(\"read metric name: %w\", err)\n 746→\t\t}\n 747→\n 748→\t\tvar freq, start int64\n 749→\t\tif err := binary.Read(r, binary.LittleEndian, &freq); err != nil {\n 750→\t\t\treturn nil, fmt.Errorf(\"read frequency for %s: %w\", name, err)\n 751→\t\t}\n 752→\t\tif err := binary.Read(r, binary.LittleEndian, &start); err != nil {\n 753→\t\t\treturn nil, fmt.Errorf(\"read start for %s: %w\", name, err)\n 754→\t\t}\n 755→\n 756→\t\tvar numValues uint32\n 757→\t\tif err := binary.Read(r, binary.LittleEndian, &numValues); err != nil {\n 758→\t\t\treturn nil, fmt.Errorf(\"read num_values for %s: %w\", name, err)\n 759→\t\t}\n 760→\n 761→\t\tdata := make([]schema.Float, numValues)\n 762→\t\tfor i := range numValues {\n 763→\t\t\tvar bits uint32\n 764→\t\t\tif err := binary.Read(r, binary.LittleEndian, &bits); err != nil {\n 765→\t\t\t\treturn nil, fmt.Errorf(\"read value[%d] for %s: %w\", i, name, err)\n 766→\t\t\t}\n 767→\t\t\tdata[i] = schema.Float(math.Float32frombits(bits))\n 768→\t\t}\n 769→\n 770→\t\tcf.Metrics[name] = &CheckpointMetrics{\n 771→\t\t\tFrequency: freq,\n 772→\t\t\tStart: start,\n 773→\t\t\tData: data,\n 774→\t\t}\n 775→\t}\n 776→\n 777→\tvar numChildren uint32\n 778→\tif err := binary.Read(r, binary.LittleEndian, &numChildren); err != nil {\n 779→\t\treturn nil, fmt.Errorf(\"read num_children: %w\", err)\n 780→\t}\n 781→\n 782→\tfor range numChildren {\n 783→\t\tchildName, err := readString16(r)\n 784→\t\tif err != nil {\n 785→\t\t\treturn nil, fmt.Errorf(\"read child name: %w\", err)\n 786→\t\t}\n 787→\n 788→\t\tchild, err := readBinaryLevel(r)\n 789→\t\tif err != nil {\n 790→\t\t\treturn nil, fmt.Errorf(\"read child %s: %w\", childName, err)\n 791→\t\t}\n 792→\t\tcf.Children[childName] = child\n 793→\t}\n 794→\n 795→\treturn cf, nil\n 796→}\n 797→\n 798→// readString16 reads a 2-byte length-prefixed string from r.\n 799→func readString16(r io.Reader) (string, error) {\n 800→\tvar sLen uint16\n 801→\tif err := binary.Read(r, binary.LittleEndian, &sLen); err != nil {\n 802→\t\treturn \"\", err\n 803→\t}\n 804→\tbuf := make([]byte, sLen)\n 805→\tif _, err := io.ReadFull(r, buf); err != nil {\n 806→\t\treturn \"\", err\n 807→\t}\n 808→\treturn string(buf), nil\n 809→}\n 810→"}]},"uuid":"9f0eeed1-fa92-4a09-8281-3e703bbe7f66","timestamp":"2026-03-18T05:08:48.245Z","toolUseResult":{"type":"text","file":{"filePath":"/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/walCheckpoint.go","content":"// Copyright (C) NHR@FAU, University Erlangen-Nuremberg.\n// All rights reserved. This file is part of cc-backend.\n// Use of this source code is governed by a MIT-style\n// license that can be found in the LICENSE file.\n\n// Package metricstore provides walCheckpoint.go: WAL-based checkpoint implementation.\n//\n// This replaces the Avro shadow tree with an append-only Write-Ahead Log (WAL)\n// per host, eliminating the extra memory overhead of the AvroStore and providing\n// truly continuous (per-write) crash safety.\n//\n// # Architecture\n//\n//\tMetric write (DecodeLine)\n//\t │\n//\t ├─► WriteToLevel() → main MemoryStore (unchanged)\n//\t │\n//\t └─► WALMessages channel\n//\t │\n//\t ▼\n//\t WALStaging goroutine\n//\t │\n//\t ▼\n//\t checkpoints/cluster/host/current.wal (append-only, binary)\n//\n//\tPeriodic checkpoint (Checkpointing goroutine):\n//\t 1. Write .bin snapshot (column-oriented, from main tree)\n//\t 2. Signal WALStaging to truncate current.wal per host\n//\n//\tOn restart (FromCheckpoint):\n//\t 1. Load most recent .bin snapshot\n//\t 2. Replay current.wal (overwrite-safe: buffer.write handles duplicate timestamps)\n//\n// # WAL Record Format\n//\n//\t[4B magic 0xCC1DA7A1][4B payload_len][payload][4B CRC32]\n//\n//\tpayload:\n//\t [8B timestamp int64]\n//\t [2B metric_name_len uint16][N metric name bytes]\n//\t [1B selector_count uint8]\n//\t per selector: [1B selector_len uint8][M selector bytes]\n//\t [4B value float32 bits]\n//\n// # Binary Snapshot Format\n//\n//\t[4B magic 0xCC5B0001][8B from int64][8B to int64]\n//\tLevel tree (recursive):\n//\t [4B num_metrics uint32]\n//\t per metric:\n//\t [2B name_len uint16][N name bytes]\n//\t [8B frequency int64][8B start int64]\n//\t [4B num_values uint32][num_values × 4B float32]\n//\t [4B num_children uint32]\n//\t per child: [2B name_len uint16][N name bytes] + Level (recursive)\npackage metricstore\n\nimport (\n\t\"bufio\"\n\t\"context\"\n\t\"encoding/binary\"\n\t\"fmt\"\n\t\"hash/crc32\"\n\t\"io\"\n\t\"math\"\n\t\"os\"\n\t\"path\"\n\t\"strings\"\n\t\"sync\"\n\t\"sync/atomic\"\n\n\tcclog \"github.com/ClusterCockpit/cc-lib/v2/ccLogger\"\n\t\"github.com/ClusterCockpit/cc-lib/v2/schema\"\n)\n\n// Magic numbers for binary formats.\nconst (\n\twalFileMagic = uint32(0xCC1DA701) // WAL file header magic\n\twalRecordMagic = uint32(0xCC1DA7A1) // WAL record magic\n\tsnapFileMagic = uint32(0xCC5B0001) // Binary snapshot magic\n)\n\n// WALMessages is the channel for sending metric writes to the WAL staging goroutine.\n// Buffered to allow burst writes without blocking the metric ingestion path.\nvar WALMessages = make(chan *WALMessage, 4096)\n\n// walRotateCh is used by the checkpoint goroutine to request WAL file rotation\n// (close, delete, reopen) after a binary snapshot has been written.\nvar walRotateCh = make(chan walRotateReq, 256)\n\n// WALMessage represents a single metric write to be appended to the WAL.\n// Cluster and Node are NOT stored in the WAL record (inferred from file path).\ntype WALMessage struct {\n\tMetricName string\n\tCluster string\n\tNode string\n\tSelector []string\n\tValue schema.Float\n\tTimestamp int64\n}\n\n// walRotateReq requests WAL file rotation for a specific host directory.\n// The done channel is closed by the WAL goroutine when rotation is complete.\ntype walRotateReq struct {\n\thostDir string\n\tdone chan struct{}\n}\n\n// walFileState holds an open WAL file handle and buffered writer for one host directory.\ntype walFileState struct {\n\tf *os.File\n\tw *bufio.Writer\n}\n\n// WALStaging starts a background goroutine that receives WALMessage items\n// and appends binary WAL records to per-host current.wal files.\n// Also handles WAL rotation requests from the checkpoint goroutine.\nfunc WALStaging(wg *sync.WaitGroup, ctx context.Context) {\n\twg.Go(func() {\n\t\tif Keys.Checkpoints.FileFormat == \"json\" {\n\t\t\treturn\n\t\t}\n\n\t\thostFiles := make(map[string]*walFileState)\n\n\t\tdefer func() {\n\t\t\tfor _, ws := range hostFiles {\n\t\t\t\tif ws.f != nil {\n\t\t\t\t\tws.w.Flush()\n\t\t\t\t\tws.f.Close()\n\t\t\t\t}\n\t\t\t}\n\t\t}()\n\n\t\tgetOrOpenWAL := func(hostDir string) *walFileState {\n\t\t\tws, ok := hostFiles[hostDir]\n\t\t\tif ok {\n\t\t\t\treturn ws\n\t\t\t}\n\n\t\t\tif err := os.MkdirAll(hostDir, CheckpointDirPerms); err != nil {\n\t\t\t\tcclog.Errorf(\"[METRICSTORE]> WAL: mkdir %s: %v\", hostDir, err)\n\t\t\t\treturn nil\n\t\t\t}\n\n\t\t\twalPath := path.Join(hostDir, \"current.wal\")\n\t\t\tf, err := os.OpenFile(walPath, os.O_CREATE|os.O_APPEND|os.O_WRONLY, CheckpointFilePerms)\n\t\t\tif err != nil {\n\t\t\t\tcclog.Errorf(\"[METRICSTORE]> WAL: open %s: %v\", walPath, err)\n\t\t\t\treturn nil\n\t\t\t}\n\n\t\t\tw := bufio.NewWriter(f)\n\n\t\t\t// Write file header magic if file is new (empty).\n\t\t\tinfo, err := f.Stat()\n\t\t\tif err == nil && info.Size() == 0 {\n\t\t\t\tvar hdr [4]byte\n\t\t\t\tbinary.LittleEndian.PutUint32(hdr[:], walFileMagic)\n\t\t\t\tif _, err := w.Write(hdr[:]); err != nil {\n\t\t\t\t\tcclog.Errorf(\"[METRICSTORE]> WAL: write header %s: %v\", walPath, err)\n\t\t\t\t\tf.Close()\n\t\t\t\t\treturn nil\n\t\t\t\t}\n\t\t\t}\n\n\t\t\tws = &walFileState{f: f, w: w}\n\t\t\thostFiles[hostDir] = ws\n\t\t\treturn ws\n\t\t}\n\n\t\tprocessMsg := func(msg *WALMessage) {\n\t\t\thostDir := path.Join(Keys.Checkpoints.RootDir, msg.Cluster, msg.Node)\n\t\t\tws := getOrOpenWAL(hostDir)\n\t\t\tif ws == nil {\n\t\t\t\treturn\n\t\t\t}\n\t\t\tif err := writeWALRecord(ws.w, msg); err != nil {\n\t\t\t\tcclog.Errorf(\"[METRICSTORE]> WAL: write record: %v\", err)\n\t\t\t}\n\t\t}\n\n\t\tprocessRotate := func(req walRotateReq) {\n\t\t\tws, ok := hostFiles[req.hostDir]\n\t\t\tif ok && ws.f != nil {\n\t\t\t\tws.w.Flush()\n\t\t\t\tws.f.Close()\n\t\t\t\twalPath := path.Join(req.hostDir, \"current.wal\")\n\t\t\t\tif err := os.Remove(walPath); err != nil && !os.IsNotExist(err) {\n\t\t\t\t\tcclog.Errorf(\"[METRICSTORE]> WAL: remove %s: %v\", walPath, err)\n\t\t\t\t}\n\t\t\t\tdelete(hostFiles, req.hostDir)\n\t\t\t}\n\t\t\tclose(req.done)\n\t\t}\n\n\t\tdrain := func() {\n\t\t\tfor {\n\t\t\t\tselect {\n\t\t\t\tcase msg, ok := <-WALMessages:\n\t\t\t\t\tif !ok {\n\t\t\t\t\t\treturn\n\t\t\t\t\t}\n\t\t\t\t\tprocessMsg(msg)\n\t\t\t\tcase req := <-walRotateCh:\n\t\t\t\t\tprocessRotate(req)\n\t\t\t\tdefault:\n\t\t\t\t\t// Flush all buffered writers after draining remaining messages.\n\t\t\t\t\tfor _, ws := range hostFiles {\n\t\t\t\t\t\tif ws.f != nil {\n\t\t\t\t\t\t\tws.w.Flush()\n\t\t\t\t\t\t}\n\t\t\t\t\t}\n\t\t\t\t\treturn\n\t\t\t\t}\n\t\t\t}\n\t\t}\n\n\t\tfor {\n\t\t\tselect {\n\t\t\tcase <-ctx.Done():\n\t\t\t\tdrain()\n\t\t\t\treturn\n\t\t\tcase msg, ok := <-WALMessages:\n\t\t\t\tif !ok {\n\t\t\t\t\treturn\n\t\t\t\t}\n\t\t\t\tprocessMsg(msg)\n\t\t\tcase req := <-walRotateCh:\n\t\t\t\tprocessRotate(req)\n\t\t\t}\n\t\t}\n\t})\n}\n\n// RotateWALFiles sends rotation requests for the given host directories\n// and blocks until all rotations complete.\nfunc RotateWALFiles(hostDirs []string) {\n\tdones := make([]chan struct{}, len(hostDirs))\n\tfor i, dir := range hostDirs {\n\t\tdones[i] = make(chan struct{})\n\t\twalRotateCh <- walRotateReq{hostDir: dir, done: dones[i]}\n\t}\n\tfor _, done := range dones {\n\t\t<-done\n\t}\n}\n\n// RotateWALFiles sends rotation requests for the given host directories\n// and blocks until all rotations complete.\nfunc RotateWALFilesAfterShutdown(hostDirs []string) {\n\tfor _, dir := range hostDirs {\n\t\twalPath := path.Join(dir, \"current.wal\")\n\t\tif err := os.Remove(walPath); err != nil && !os.IsNotExist(err) {\n\t\t\tcclog.Errorf(\"[METRICSTORE]> WAL: remove %s: %v\", walPath, err)\n\t\t}\n\t}\n}\n\n// buildWALPayload encodes a WALMessage into a binary payload (without magic/length/CRC).\nfunc buildWALPayload(msg *WALMessage) []byte {\n\tsize := 8 + 2 + len(msg.MetricName) + 1 + 4\n\tfor _, s := range msg.Selector {\n\t\tsize += 1 + len(s)\n\t}\n\n\tbuf := make([]byte, 0, size)\n\n\t// Timestamp (8 bytes, little-endian int64)\n\tvar ts [8]byte\n\tbinary.LittleEndian.PutUint64(ts[:], uint64(msg.Timestamp))\n\tbuf = append(buf, ts[:]...)\n\n\t// Metric name (2-byte length prefix + bytes)\n\tvar mLen [2]byte\n\tbinary.LittleEndian.PutUint16(mLen[:], uint16(len(msg.MetricName)))\n\tbuf = append(buf, mLen[:]...)\n\tbuf = append(buf, msg.MetricName...)\n\n\t// Selector count (1 byte)\n\tbuf = append(buf, byte(len(msg.Selector)))\n\n\t// Selectors (1-byte length prefix + bytes each)\n\tfor _, sel := range msg.Selector {\n\t\tbuf = append(buf, byte(len(sel)))\n\t\tbuf = append(buf, sel...)\n\t}\n\n\t// Value (4 bytes, float32 bit representation)\n\tvar val [4]byte\n\tbinary.LittleEndian.PutUint32(val[:], math.Float32bits(float32(msg.Value)))\n\tbuf = append(buf, val[:]...)\n\n\treturn buf\n}\n\n// writeWALRecord appends a binary WAL record to the writer.\n// Format: [4B magic][4B payload_len][payload][4B CRC32]\nfunc writeWALRecord(w io.Writer, msg *WALMessage) error {\n\tpayload := buildWALPayload(msg)\n\tcrc := crc32.ChecksumIEEE(payload)\n\n\trecord := make([]byte, 0, 4+4+len(payload)+4)\n\n\tvar magic [4]byte\n\tbinary.LittleEndian.PutUint32(magic[:], walRecordMagic)\n\trecord = append(record, magic[:]...)\n\n\tvar pLen [4]byte\n\tbinary.LittleEndian.PutUint32(pLen[:], uint32(len(payload)))\n\trecord = append(record, pLen[:]...)\n\n\trecord = append(record, payload...)\n\n\tvar crcBytes [4]byte\n\tbinary.LittleEndian.PutUint32(crcBytes[:], crc)\n\trecord = append(record, crcBytes[:]...)\n\n\t_, err := w.Write(record)\n\treturn err\n}\n\n// readWALRecord reads one WAL record from the reader.\n// Returns (nil, nil) on clean EOF. Returns error on data corruption.\n// A CRC mismatch indicates a truncated trailing record (expected on crash).\nfunc readWALRecord(r io.Reader) (*WALMessage, error) {\n\tvar magic uint32\n\tif err := binary.Read(r, binary.LittleEndian, &magic); err != nil {\n\t\tif err == io.EOF {\n\t\t\treturn nil, nil // Clean EOF\n\t\t}\n\t\treturn nil, fmt.Errorf(\"read record magic: %w\", err)\n\t}\n\n\tif magic != walRecordMagic {\n\t\treturn nil, fmt.Errorf(\"invalid record magic 0x%08X (expected 0x%08X)\", magic, walRecordMagic)\n\t}\n\n\tvar payloadLen uint32\n\tif err := binary.Read(r, binary.LittleEndian, &payloadLen); err != nil {\n\t\treturn nil, fmt.Errorf(\"read payload length: %w\", err)\n\t}\n\n\tif payloadLen > 1<<20 { // 1 MB sanity limit\n\t\treturn nil, fmt.Errorf(\"record payload too large: %d bytes\", payloadLen)\n\t}\n\n\tpayload := make([]byte, payloadLen)\n\tif _, err := io.ReadFull(r, payload); err != nil {\n\t\treturn nil, fmt.Errorf(\"read payload: %w\", err)\n\t}\n\n\tvar storedCRC uint32\n\tif err := binary.Read(r, binary.LittleEndian, &storedCRC); err != nil {\n\t\treturn nil, fmt.Errorf(\"read CRC: %w\", err)\n\t}\n\n\tif crc32.ChecksumIEEE(payload) != storedCRC {\n\t\treturn nil, fmt.Errorf(\"CRC mismatch (truncated write or corruption)\")\n\t}\n\n\treturn parseWALPayload(payload)\n}\n\n// parseWALPayload decodes a binary payload into a WALMessage.\nfunc parseWALPayload(payload []byte) (*WALMessage, error) {\n\tif len(payload) < 8+2+1+4 {\n\t\treturn nil, fmt.Errorf(\"payload too short: %d bytes\", len(payload))\n\t}\n\n\toffset := 0\n\n\t// Timestamp (8 bytes)\n\tts := int64(binary.LittleEndian.Uint64(payload[offset : offset+8]))\n\toffset += 8\n\n\t// Metric name (2-byte length + bytes)\n\tif offset+2 > len(payload) {\n\t\treturn nil, fmt.Errorf(\"metric name length overflows payload\")\n\t}\n\tmLen := int(binary.LittleEndian.Uint16(payload[offset : offset+2]))\n\toffset += 2\n\n\tif offset+mLen > len(payload) {\n\t\treturn nil, fmt.Errorf(\"metric name overflows payload\")\n\t}\n\tmetricName := string(payload[offset : offset+mLen])\n\toffset += mLen\n\n\t// Selector count (1 byte)\n\tif offset >= len(payload) {\n\t\treturn nil, fmt.Errorf(\"selector count overflows payload\")\n\t}\n\tselCount := int(payload[offset])\n\toffset++\n\n\tselectors := make([]string, selCount)\n\tfor i := range selCount {\n\t\tif offset >= len(payload) {\n\t\t\treturn nil, fmt.Errorf(\"selector[%d] length overflows payload\", i)\n\t\t}\n\t\tsLen := int(payload[offset])\n\t\toffset++\n\n\t\tif offset+sLen > len(payload) {\n\t\t\treturn nil, fmt.Errorf(\"selector[%d] data overflows payload\", i)\n\t\t}\n\t\tselectors[i] = string(payload[offset : offset+sLen])\n\t\toffset += sLen\n\t}\n\n\t// Value (4 bytes, float32 bits)\n\tif offset+4 > len(payload) {\n\t\treturn nil, fmt.Errorf(\"value overflows payload\")\n\t}\n\tbits := binary.LittleEndian.Uint32(payload[offset : offset+4])\n\tvalue := schema.Float(math.Float32frombits(bits))\n\n\treturn &WALMessage{\n\t\tMetricName: metricName,\n\t\tTimestamp: ts,\n\t\tSelector: selectors,\n\t\tValue: value,\n\t}, nil\n}\n\n// loadWALFile reads a WAL file and replays all valid records into the Level tree.\n// l is the host-level node. Corrupt or partial trailing records are silently skipped\n// (expected on crash). Records older than 'from' are skipped.\nfunc (l *Level) loadWALFile(m *MemoryStore, f *os.File, from int64) error {\n\tbr := bufio.NewReader(f)\n\n\t// Verify file header magic.\n\tvar fileMagic uint32\n\tif err := binary.Read(br, binary.LittleEndian, &fileMagic); err != nil {\n\t\tif err == io.EOF {\n\t\t\treturn nil // Empty file, no data\n\t\t}\n\t\treturn fmt.Errorf(\"[METRICSTORE]> WAL: read file header: %w\", err)\n\t}\n\n\tif fileMagic != walFileMagic {\n\t\treturn fmt.Errorf(\"[METRICSTORE]> WAL: invalid file magic 0x%08X (expected 0x%08X)\", fileMagic, walFileMagic)\n\t}\n\n\t// Cache level lookups to avoid repeated tree traversal.\n\tlvlCache := make(map[string]*Level)\n\n\tfor {\n\t\tmsg, err := readWALRecord(br)\n\t\tif err != nil {\n\t\t\t// Truncated trailing record is expected after a crash; stop replaying.\n\t\t\tcclog.Debugf(\"[METRICSTORE]> WAL: stopping replay at corrupted/partial record: %v\", err)\n\t\t\tbreak\n\t\t}\n\t\tif msg == nil {\n\t\t\tbreak // Clean EOF\n\t\t}\n\n\t\tif msg.Timestamp < from {\n\t\t\tcontinue // Older than retention window\n\t\t}\n\n\t\tminfo, ok := m.Metrics[msg.MetricName]\n\t\tif !ok {\n\t\t\tcontinue // Unknown metric (config may have changed)\n\t\t}\n\n\t\t// Cache key is the null-separated selector path.\n\t\tcacheKey := joinSelector(msg.Selector)\n\t\tlvl, ok := lvlCache[cacheKey]\n\t\tif !ok {\n\t\t\tlvl = l.findLevelOrCreate(msg.Selector, len(m.Metrics))\n\t\t\tlvlCache[cacheKey] = lvl\n\t\t}\n\n\t\t// Write directly to the buffer, same as WriteToLevel but without the\n\t\t// global level lookup (we already have the right level).\n\t\tlvl.lock.Lock()\n\t\tb := lvl.metrics[minfo.offset]\n\t\tif b == nil {\n\t\t\tb = newBuffer(msg.Timestamp, minfo.Frequency)\n\t\t\tlvl.metrics[minfo.offset] = b\n\t\t}\n\t\tnb, writeErr := b.write(msg.Timestamp, msg.Value)\n\t\tif writeErr == nil && b != nb {\n\t\t\tlvl.metrics[minfo.offset] = nb\n\t\t}\n\t\t// Ignore write errors for timestamps before buffer start (can happen when\n\t\t// replaying WAL entries that predate a loaded snapshot's start time).\n\t\tlvl.lock.Unlock()\n\t}\n\n\treturn nil\n}\n\n// joinSelector builds a cache key from a selector slice using null bytes as separators.\nfunc joinSelector(sel []string) string {\n\tif len(sel) == 0 {\n\t\treturn \"\"\n\t}\n\tvar result strings.Builder\n\tresult.WriteString(sel[0])\n\tfor i := 1; i < len(sel); i++ {\n\t\tresult.WriteString(\"\\x00\" + sel[i])\n\t}\n\treturn result.String()\n}\n\n// ToCheckpointWAL writes binary snapshot files for all hosts in parallel.\n// Returns the number of files written, the list of host directories that were\n// successfully checkpointed (for WAL rotation), and any errors.\nfunc (m *MemoryStore) ToCheckpointWAL(dir string, from, to int64) (int, []string, error) {\n\t// Collect all cluster/host pairs.\n\tm.root.lock.RLock()\n\ttotalHosts := 0\n\tfor _, l1 := range m.root.children {\n\t\tl1.lock.RLock()\n\t\ttotalHosts += len(l1.children)\n\t\tl1.lock.RUnlock()\n\t}\n\tm.root.lock.RUnlock()\n\n\tlevels := make([]*Level, 0, totalHosts)\n\tselectors := make([][]string, 0, totalHosts)\n\n\tm.root.lock.RLock()\n\tfor sel1, l1 := range m.root.children {\n\t\tl1.lock.RLock()\n\t\tfor sel2, l2 := range l1.children {\n\t\t\tlevels = append(levels, l2)\n\t\t\tselectors = append(selectors, []string{sel1, sel2})\n\t\t}\n\t\tl1.lock.RUnlock()\n\t}\n\tm.root.lock.RUnlock()\n\n\ttype workItem struct {\n\t\tlevel *Level\n\t\thostDir string\n\t\tselector []string\n\t}\n\n\tn, errs := int32(0), int32(0)\n\tvar successDirs []string\n\tvar successMu sync.Mutex\n\n\tvar wg sync.WaitGroup\n\twg.Add(Keys.NumWorkers)\n\twork := make(chan workItem, Keys.NumWorkers*2)\n\n\tfor range Keys.NumWorkers {\n\t\tgo func() {\n\t\t\tdefer wg.Done()\n\t\t\tfor wi := range work {\n\t\t\t\terr := wi.level.toCheckpointBinary(wi.hostDir, from, to, m)\n\t\t\t\tif err != nil {\n\t\t\t\t\tif err == ErrNoNewArchiveData {\n\t\t\t\t\t\tcontinue\n\t\t\t\t\t}\n\t\t\t\t\tcclog.Errorf(\"[METRICSTORE]> binary checkpoint error for %s: %v\", wi.hostDir, err)\n\t\t\t\t\tatomic.AddInt32(&errs, 1)\n\t\t\t\t} else {\n\t\t\t\t\tatomic.AddInt32(&n, 1)\n\t\t\t\t\tsuccessMu.Lock()\n\t\t\t\t\tsuccessDirs = append(successDirs, wi.hostDir)\n\t\t\t\t\tsuccessMu.Unlock()\n\t\t\t\t}\n\t\t\t}\n\t\t}()\n\t}\n\n\tfor i := range levels {\n\t\thostDir := path.Join(dir, path.Join(selectors[i]...))\n\t\twork <- workItem{\n\t\t\tlevel: levels[i],\n\t\t\thostDir: hostDir,\n\t\t\tselector: selectors[i],\n\t\t}\n\t}\n\tclose(work)\n\twg.Wait()\n\n\tif errs > 0 {\n\t\treturn int(n), successDirs, fmt.Errorf(\"[METRICSTORE]> %d errors during binary checkpoint (%d successes)\", errs, n)\n\t}\n\treturn int(n), successDirs, nil\n}\n\n// toCheckpointBinary writes a binary snapshot file for a single host-level node.\n// Uses atomic rename (write to .tmp then rename) to avoid partial reads on crash.\nfunc (l *Level) toCheckpointBinary(dir string, from, to int64, m *MemoryStore) error {\n\tcf, err := l.toCheckpointFile(from, to, m)\n\tif err != nil {\n\t\treturn err\n\t}\n\tif cf == nil {\n\t\treturn ErrNoNewArchiveData\n\t}\n\n\tif err := os.MkdirAll(dir, CheckpointDirPerms); err != nil {\n\t\treturn fmt.Errorf(\"mkdir %s: %w\", dir, err)\n\t}\n\n\t// Write to a temp file first, then rename (atomic on POSIX).\n\ttmpPath := path.Join(dir, fmt.Sprintf(\"%d.bin.tmp\", from))\n\tfinalPath := path.Join(dir, fmt.Sprintf(\"%d.bin\", from))\n\n\tf, err := os.OpenFile(tmpPath, os.O_CREATE|os.O_WRONLY|os.O_TRUNC, CheckpointFilePerms)\n\tif err != nil {\n\t\treturn fmt.Errorf(\"open binary snapshot %s: %w\", tmpPath, err)\n\t}\n\n\tbw := bufio.NewWriter(f)\n\tif err := writeBinarySnapshotFile(bw, cf); err != nil {\n\t\tf.Close()\n\t\tos.Remove(tmpPath)\n\t\treturn fmt.Errorf(\"write binary snapshot: %w\", err)\n\t}\n\tif err := bw.Flush(); err != nil {\n\t\tf.Close()\n\t\tos.Remove(tmpPath)\n\t\treturn err\n\t}\n\tf.Close()\n\n\treturn os.Rename(tmpPath, finalPath)\n}\n\n// writeBinarySnapshotFile writes the binary snapshot file header and level tree.\nfunc writeBinarySnapshotFile(w io.Writer, cf *CheckpointFile) error {\n\tif err := binary.Write(w, binary.LittleEndian, snapFileMagic); err != nil {\n\t\treturn err\n\t}\n\tif err := binary.Write(w, binary.LittleEndian, cf.From); err != nil {\n\t\treturn err\n\t}\n\tif err := binary.Write(w, binary.LittleEndian, cf.To); err != nil {\n\t\treturn err\n\t}\n\treturn writeBinaryLevel(w, cf)\n}\n\n// writeBinaryLevel recursively writes a CheckpointFile level in binary format.\nfunc writeBinaryLevel(w io.Writer, cf *CheckpointFile) error {\n\tif err := binary.Write(w, binary.LittleEndian, uint32(len(cf.Metrics))); err != nil {\n\t\treturn err\n\t}\n\n\tfor name, metric := range cf.Metrics {\n\t\tif err := writeString16(w, name); err != nil {\n\t\t\treturn err\n\t\t}\n\t\tif err := binary.Write(w, binary.LittleEndian, metric.Frequency); err != nil {\n\t\t\treturn err\n\t\t}\n\t\tif err := binary.Write(w, binary.LittleEndian, metric.Start); err != nil {\n\t\t\treturn err\n\t\t}\n\t\tif err := binary.Write(w, binary.LittleEndian, uint32(len(metric.Data))); err != nil {\n\t\t\treturn err\n\t\t}\n\t\tfor _, v := range metric.Data {\n\t\t\tif err := binary.Write(w, binary.LittleEndian, math.Float32bits(float32(v))); err != nil {\n\t\t\t\treturn err\n\t\t\t}\n\t\t}\n\t}\n\n\tif err := binary.Write(w, binary.LittleEndian, uint32(len(cf.Children))); err != nil {\n\t\treturn err\n\t}\n\n\tfor name, child := range cf.Children {\n\t\tif err := writeString16(w, name); err != nil {\n\t\t\treturn err\n\t\t}\n\t\tif err := writeBinaryLevel(w, child); err != nil {\n\t\t\treturn err\n\t\t}\n\t}\n\n\treturn nil\n}\n\n// writeString16 writes a 2-byte length-prefixed string to w.\nfunc writeString16(w io.Writer, s string) error {\n\tif err := binary.Write(w, binary.LittleEndian, uint16(len(s))); err != nil {\n\t\treturn err\n\t}\n\t_, err := io.WriteString(w, s)\n\treturn err\n}\n\n// loadBinaryFile reads a binary snapshot file and loads data into the Level tree.\n// The retention check (from) is applied to the file's 'to' timestamp.\nfunc (l *Level) loadBinaryFile(m *MemoryStore, f *os.File, from int64) error {\n\tbr := bufio.NewReader(f)\n\n\tvar magic uint32\n\tif err := binary.Read(br, binary.LittleEndian, &magic); err != nil {\n\t\treturn fmt.Errorf(\"[METRICSTORE]> binary snapshot: read magic: %w\", err)\n\t}\n\tif magic != snapFileMagic {\n\t\treturn fmt.Errorf(\"[METRICSTORE]> binary snapshot: invalid magic 0x%08X (expected 0x%08X)\", magic, snapFileMagic)\n\t}\n\n\tvar fileFrom, fileTo int64\n\tif err := binary.Read(br, binary.LittleEndian, &fileFrom); err != nil {\n\t\treturn fmt.Errorf(\"[METRICSTORE]> binary snapshot: read from: %w\", err)\n\t}\n\tif err := binary.Read(br, binary.LittleEndian, &fileTo); err != nil {\n\t\treturn fmt.Errorf(\"[METRICSTORE]> binary snapshot: read to: %w\", err)\n\t}\n\n\tif fileTo != 0 && fileTo < from {\n\t\treturn nil // File is older than retention window, skip it\n\t}\n\n\tcf, err := readBinaryLevel(br)\n\tif err != nil {\n\t\treturn fmt.Errorf(\"[METRICSTORE]> binary snapshot: read level tree: %w\", err)\n\t}\n\tcf.From = fileFrom\n\tcf.To = fileTo\n\n\treturn l.loadFile(cf, m)\n}\n\n// readBinaryLevel recursively reads a level from the binary snapshot format.\nfunc readBinaryLevel(r io.Reader) (*CheckpointFile, error) {\n\tcf := &CheckpointFile{\n\t\tMetrics: make(map[string]*CheckpointMetrics),\n\t\tChildren: make(map[string]*CheckpointFile),\n\t}\n\n\tvar numMetrics uint32\n\tif err := binary.Read(r, binary.LittleEndian, &numMetrics); err != nil {\n\t\treturn nil, fmt.Errorf(\"read num_metrics: %w\", err)\n\t}\n\n\tfor range numMetrics {\n\t\tname, err := readString16(r)\n\t\tif err != nil {\n\t\t\treturn nil, fmt.Errorf(\"read metric name: %w\", err)\n\t\t}\n\n\t\tvar freq, start int64\n\t\tif err := binary.Read(r, binary.LittleEndian, &freq); err != nil {\n\t\t\treturn nil, fmt.Errorf(\"read frequency for %s: %w\", name, err)\n\t\t}\n\t\tif err := binary.Read(r, binary.LittleEndian, &start); err != nil {\n\t\t\treturn nil, fmt.Errorf(\"read start for %s: %w\", name, err)\n\t\t}\n\n\t\tvar numValues uint32\n\t\tif err := binary.Read(r, binary.LittleEndian, &numValues); err != nil {\n\t\t\treturn nil, fmt.Errorf(\"read num_values for %s: %w\", name, err)\n\t\t}\n\n\t\tdata := make([]schema.Float, numValues)\n\t\tfor i := range numValues {\n\t\t\tvar bits uint32\n\t\t\tif err := binary.Read(r, binary.LittleEndian, &bits); err != nil {\n\t\t\t\treturn nil, fmt.Errorf(\"read value[%d] for %s: %w\", i, name, err)\n\t\t\t}\n\t\t\tdata[i] = schema.Float(math.Float32frombits(bits))\n\t\t}\n\n\t\tcf.Metrics[name] = &CheckpointMetrics{\n\t\t\tFrequency: freq,\n\t\t\tStart: start,\n\t\t\tData: data,\n\t\t}\n\t}\n\n\tvar numChildren uint32\n\tif err := binary.Read(r, binary.LittleEndian, &numChildren); err != nil {\n\t\treturn nil, fmt.Errorf(\"read num_children: %w\", err)\n\t}\n\n\tfor range numChildren {\n\t\tchildName, err := readString16(r)\n\t\tif err != nil {\n\t\t\treturn nil, fmt.Errorf(\"read child name: %w\", err)\n\t\t}\n\n\t\tchild, err := readBinaryLevel(r)\n\t\tif err != nil {\n\t\t\treturn nil, fmt.Errorf(\"read child %s: %w\", childName, err)\n\t\t}\n\t\tcf.Children[childName] = child\n\t}\n\n\treturn cf, nil\n}\n\n// readString16 reads a 2-byte length-prefixed string from r.\nfunc readString16(r io.Reader) (string, error) {\n\tvar sLen uint16\n\tif err := binary.Read(r, binary.LittleEndian, &sLen); err != nil {\n\t\treturn \"\", err\n\t}\n\tbuf := make([]byte, sLen)\n\tif _, err := io.ReadFull(r, buf); err != nil {\n\t\treturn \"\", err\n\t}\n\treturn string(buf), 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RetentionInMemory: Duration string (e.g., \"48h\") for in-memory data retention\npkg/metricstore/config.go-116-/ - MemoryCap: Max memory in GB for buffer data (0 = unlimited); triggers forceFree when exceeded\n--\npkg/metricstore/config.go-119-/ - Archive: Long-term storage configuration (nil = disabled)\npkg/metricstore/config.go-120-/ - Subscriptions: NATS topics for metric ingestion (nil = polling only)\npkg/metricstore/config.go:121:type MetricStoreConfig struct {\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/config.go-122-\t// Number of concurrent workers for checkpoint and archive operations.\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/config.go-123-\t// If not set or 0, defaults to min(runtime.NumCPU()/2+1, 10)\npkg/metricstore/config.go:124:\tNumWorkers int `json:\"num-workers\"`\npkg/metricstore/config.go-125-\tRetentionInMemory string `json:\"retention-in-memory\"`\npkg/metricstore/config.go-126-\tCheckpointInterval string `json:\"checkpoint-interval,omitempty\"`\n--\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/metricstore.go-134-\t}\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/metricstore.go-135-\npkg/metricstore/metricstore.go:136:\t// Set NumWorkers from config or use default\npkg/metricstore/metricstore.go:137:\tif Keys.NumWorkers <= 0 {\npkg/metricstore/metricstore.go:138:\t\tKeys.NumWorkers = min(runtime.NumCPU()/2+1, DefaultMaxWorkers)\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/metricstore.go-139-\t}\npkg/metricstore/metricstore.go:140:\tcclog.Debugf(\"[METRICSTORE]> Using %d workers for checkpoint/archive operations\\n\", Keys.NumWorkers)\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/metricstore.go-141-\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/metricstore.go-142-\t// Pass the config.MetricStoreKeys\n--\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/checkpoint.go-182-//\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/checkpoint.go-183-// Metrics at root and cluster levels are skipped. One file per host is created.\npkg/metricstore/checkpoint.go:184:// Uses worker pool (Keys.NumWorkers) for parallel processing. Only locks one host\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/checkpoint.go-185-// at a time, allowing concurrent writes/reads to other hosts.\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/checkpoint.go-186-//\n--\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/checkpoint.go-220-\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/checkpoint.go-221-\tvar wg sync.WaitGroup\npkg/metricstore/checkpoint.go:222:\twg.Add(Keys.NumWorkers)\npkg/metricstore/checkpoint.go:223:\twork := make(chan workItem, Keys.NumWorkers*2)\npkg/metricstore/checkpoint.go:224:\tfor worker := 0; worker < Keys.NumWorkers; worker++ {\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/checkpoint.go-225-\t\tgo func() {\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/checkpoint.go-226-\t\t\tdefer wg.Done()\n--\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/checkpoint.go-395-func (m *MemoryStore) FromCheckpoint(dir string, from int64) (int, error) {\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/checkpoint.go-396-\tvar wg sync.WaitGroup\npkg/metricstore/checkpoint.go:397:\twork := make(chan [2]string, Keys.NumWorkers*4)\npkg/metricstore/checkpoint.go-398-\tn, errs := int32(0), int32(0)\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/checkpoint.go-399-\npkg/metricstore/checkpoint.go:400:\twg.Add(Keys.NumWorkers)\npkg/metricstore/checkpoint.go:401:\tfor worker := 0; worker < Keys.NumWorkers; worker++ {\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/checkpoint.go-402-\t\tgo func() {\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/checkpoint.go-403-\t\t\tdefer wg.Done()\n--\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/archive.go-106-\tvar wg sync.WaitGroup\npkg/metricstore/archive.go-107-\tn, errs := int32(0), int32(0)\npkg/metricstore/archive.go:108:\twork := make(chan workItem, Keys.NumWorkers)\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/archive.go-109-\npkg/metricstore/archive.go:110:\twg.Add(Keys.NumWorkers)\npkg/metricstore/archive.go:111:\tfor worker := 0; worker < Keys.NumWorkers; worker++ {\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/archive.go-112-\t\tgo func() {\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/archive.go-113-\t\t\tdefer wg.Done()\n--\npkg/metricstore/archive.go-203-\t\twork := make(chan struct {\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/archive.go-204-\t\t\tdir, host string\npkg/metricstore/archive.go:205:\t\t}, Keys.NumWorkers)\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/archive.go-206-\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/archive.go-207-\t\tvar wg sync.WaitGroup\npkg/metricstore/archive.go-208-\t\terrs := int32(0)\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/archive.go-209-\npkg/metricstore/archive.go:210:\t\twg.Add(Keys.NumWorkers)\npkg/metricstore/archive.go:211:\t\tfor w := 0; w < Keys.NumWorkers; w++ {\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/archive.go-212-\t\t\tgo func() {\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/archive.go-213-\t\t\t\tdefer wg.Done()\n--\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/walCheckpoint.go-547-\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/walCheckpoint.go-548-\tvar wg sync.WaitGroup\npkg/metricstore/walCheckpoint.go:549:\twg.Add(Keys.NumWorkers)\npkg/metricstore/walCheckpoint.go:550:\twork := make(chan workItem, Keys.NumWorkers*2)\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/walCheckpoint.go-551-\npkg/metricstore/walCheckpoint.go:552:\tfor range Keys.NumWorkers {\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/walCheckpoint.go-553-\t\tgo func() {\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/walCheckpoint.go-554-\t\t\tdefer wg.Done()"}]},"uuid":"4f367e67-6395-4951-a57e-0190d9fe3bae","timestamp":"2026-03-18T05:08:59.840Z","toolUseResult":{"mode":"content","numFiles":0,"filenames":[],"content":"/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/config.go-11-//\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/config.go-12-//\tMetricStoreConfig (Keys)\npkg/metricstore/config.go:13://\t├─ NumWorkers: Parallel checkpoint/archive workers\npkg/metricstore/config.go-14-/\t├─ RetentionInMemory: How long to keep data in RAM (also used as cleanup interval)\npkg/metricstore/config.go-15-/\t├─ MemoryCap: Memory limit in bytes (triggers forceFree)\n--\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/config.go-112-//\npkg/metricstore/config.go-113-/ Fields:\npkg/metricstore/config.go:114:// - NumWorkers: Parallel workers for checkpoint/archive (0 = auto: min(NumCPU/2+1, 10))\npkg/metricstore/config.go-115-/ - RetentionInMemory: Duration string (e.g., \"48h\") for in-memory data retention\npkg/metricstore/config.go-116-/ - MemoryCap: Max memory in GB for buffer data (0 = unlimited); triggers forceFree when exceeded\n--\npkg/metricstore/config.go-119-/ - Archive: Long-term storage configuration (nil = disabled)\npkg/metricstore/config.go-120-/ - Subscriptions: NATS topics for metric ingestion (nil = polling only)\npkg/metricstore/config.go:121:type MetricStoreConfig struct {\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/config.go-122-\t// Number of concurrent workers for checkpoint and archive operations.\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/config.go-123-\t// If not set or 0, defaults to min(runtime.NumCPU()/2+1, 10)\npkg/metricstore/config.go:124:\tNumWorkers int `json:\"num-workers\"`\npkg/metricstore/config.go-125-\tRetentionInMemory string `json:\"retention-in-memory\"`\npkg/metricstore/config.go-126-\tCheckpointInterval string `json:\"checkpoint-interval,omitempty\"`\n--\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/metricstore.go-134-\t}\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/metricstore.go-135-\npkg/metricstore/metricstore.go:136:\t// Set NumWorkers from config or use default\npkg/metricstore/metricstore.go:137:\tif Keys.NumWorkers <= 0 {\npkg/metricstore/metricstore.go:138:\t\tKeys.NumWorkers = min(runtime.NumCPU()/2+1, DefaultMaxWorkers)\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/metricstore.go-139-\t}\npkg/metricstore/metricstore.go:140:\tcclog.Debugf(\"[METRICSTORE]> Using %d workers for checkpoint/archive operations\\n\", Keys.NumWorkers)\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/metricstore.go-141-\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/metricstore.go-142-\t// Pass the config.MetricStoreKeys\n--\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/checkpoint.go-182-//\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/checkpoint.go-183-// Metrics at root and cluster levels are skipped. One file per host is created.\npkg/metricstore/checkpoint.go:184:// Uses worker pool (Keys.NumWorkers) for parallel processing. Only locks one host\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/checkpoint.go-185-// at a time, allowing concurrent writes/reads to other hosts.\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/checkpoint.go-186-//\n--\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/checkpoint.go-220-\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/checkpoint.go-221-\tvar wg sync.WaitGroup\npkg/metricstore/checkpoint.go:222:\twg.Add(Keys.NumWorkers)\npkg/metricstore/checkpoint.go:223:\twork := make(chan workItem, Keys.NumWorkers*2)\npkg/metricstore/checkpoint.go:224:\tfor worker := 0; worker < Keys.NumWorkers; worker++ {\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/checkpoint.go-225-\t\tgo func() {\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/checkpoint.go-226-\t\t\tdefer wg.Done()\n--\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/checkpoint.go-395-func (m *MemoryStore) FromCheckpoint(dir string, from int64) (int, error) {\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/checkpoint.go-396-\tvar wg sync.WaitGroup\npkg/metricstore/checkpoint.go:397:\twork := make(chan [2]string, Keys.NumWorkers*4)\npkg/metricstore/checkpoint.go-398-\tn, errs := int32(0), int32(0)\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/checkpoint.go-399-\npkg/metricstore/checkpoint.go:400:\twg.Add(Keys.NumWorkers)\npkg/metricstore/checkpoint.go:401:\tfor worker := 0; worker < Keys.NumWorkers; worker++ {\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/checkpoint.go-402-\t\tgo func() {\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/checkpoint.go-403-\t\t\tdefer wg.Done()\n--\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/archive.go-106-\tvar wg sync.WaitGroup\npkg/metricstore/archive.go-107-\tn, errs := int32(0), int32(0)\npkg/metricstore/archive.go:108:\twork := make(chan workItem, Keys.NumWorkers)\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/archive.go-109-\npkg/metricstore/archive.go:110:\twg.Add(Keys.NumWorkers)\npkg/metricstore/archive.go:111:\tfor worker := 0; worker < Keys.NumWorkers; worker++ {\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/archive.go-112-\t\tgo func() {\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/archive.go-113-\t\t\tdefer wg.Done()\n--\npkg/metricstore/archive.go-203-\t\twork := make(chan struct {\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/archive.go-204-\t\t\tdir, host string\npkg/metricstore/archive.go:205:\t\t}, Keys.NumWorkers)\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/archive.go-206-\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/archive.go-207-\t\tvar wg sync.WaitGroup\npkg/metricstore/archive.go-208-\t\terrs := int32(0)\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/archive.go-209-\npkg/metricstore/archive.go:210:\t\twg.Add(Keys.NumWorkers)\npkg/metricstore/archive.go:211:\t\tfor w := 0; w < Keys.NumWorkers; w++ {\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/archive.go-212-\t\t\tgo func() {\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/archive.go-213-\t\t\t\tdefer wg.Done()\n--\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/walCheckpoint.go-547-\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/walCheckpoint.go-548-\tvar wg sync.WaitGroup\npkg/metricstore/walCheckpoint.go:549:\twg.Add(Keys.NumWorkers)\npkg/metricstore/walCheckpoint.go:550:\twork := make(chan workItem, Keys.NumWorkers*2)\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/walCheckpoint.go-551-\npkg/metricstore/walCheckpoint.go:552:\tfor range Keys.NumWorkers {\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/walCheckpoint.go-553-\t\tgo func() {\n/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/walCheckpoint.go-554-\t\t\tdefer wg.Done()","numLines":84},"sourceToolAssistantUUID":"5ff2f92f-1915-46b7-92ab-fd1d6e5dff31","userType":"external","entrypoint":"cli","cwd":"/Users/jan/prg/ClusterCockpit/cc-backend","sessionId":"5eb20a94-f8df-4979-a0ae-2aa99bfad884","version":"2.1.78","gitBranch":"hotfix","slug":"bright-wandering-flurry"} +{"parentUuid":"4f367e67-6395-4951-a57e-0190d9fe3bae","isSidechain":false,"message":{"model":"claude-opus-4-6","id":"msg_01TMpWgjfZ2aRR8UB2CtgZyw","type":"message","role":"assistant","content":[{"type":"text","text":"Now I have all the context. Let me also check for a `walDropped` counter or similar logging pattern to understand if there's existing drop tracking."}],"stop_reason":null,"stop_sequence":null,"usage":{"input_tokens":1,"cache_creation_input_tokens":2774,"cache_read_input_tokens":47590,"cache_creation":{"ephemeral_5m_input_tokens":0,"ephemeral_1h_input_tokens":2774},"output_tokens":1,"service_tier":"standard","inference_geo":"not_available"}},"requestId":"req_011CZ9y6PsuQ2CEzpsVqqmHd","type":"assistant","uuid":"d66e69c3-cea5-4277-93b0-dd20d40259b3","timestamp":"2026-03-18T05:09:03.569Z","userType":"external","entrypoint":"cli","cwd":"/Users/jan/prg/ClusterCockpit/cc-backend","sessionId":"5eb20a94-f8df-4979-a0ae-2aa99bfad884","version":"2.1.78","gitBranch":"hotfix","slug":"bright-wandering-flurry"} +{"parentUuid":"d66e69c3-cea5-4277-93b0-dd20d40259b3","isSidechain":false,"message":{"model":"claude-opus-4-6","id":"msg_01TMpWgjfZ2aRR8UB2CtgZyw","type":"message","role":"assistant","content":[{"type":"tool_use","id":"toolu_018nSgsu8wqMZNcFMa48KFww","name":"Grep","input":{"pattern":"walDrop|wal.*drop|slow.consumer","path":"/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore","-i":true},"caller":{"type":"direct"}}],"stop_reason":"tool_use","stop_sequence":null,"usage":{"input_tokens":1,"cache_creation_input_tokens":2774,"cache_read_input_tokens":47590,"output_tokens":153,"server_tool_use":{"web_search_requests":0,"web_fetch_requests":0},"service_tier":"standard","cache_creation":{"ephemeral_1h_input_tokens":2774,"ephemeral_5m_input_tokens":0},"inference_geo":"","iterations":[],"speed":"standard"}},"requestId":"req_011CZ9y6PsuQ2CEzpsVqqmHd","type":"assistant","uuid":"d7fab323-a367-483e-8897-11ee79478d84","timestamp":"2026-03-18T05:09:04.580Z","userType":"external","entrypoint":"cli","cwd":"/Users/jan/prg/ClusterCockpit/cc-backend","sessionId":"5eb20a94-f8df-4979-a0ae-2aa99bfad884","version":"2.1.78","gitBranch":"hotfix","slug":"bright-wandering-flurry"} +{"parentUuid":"d7fab323-a367-483e-8897-11ee79478d84","isSidechain":false,"type":"progress","data":{"type":"hook_progress","hookEvent":"PostToolUse","hookName":"PostToolUse:Grep","command":"callback"},"parentToolUseID":"toolu_018nSgsu8wqMZNcFMa48KFww","toolUseID":"toolu_018nSgsu8wqMZNcFMa48KFww","timestamp":"2026-03-18T05:09:04.597Z","uuid":"c9f143f1-d344-495e-9258-d8478e78759a","userType":"external","entrypoint":"cli","cwd":"/Users/jan/prg/ClusterCockpit/cc-backend","sessionId":"5eb20a94-f8df-4979-a0ae-2aa99bfad884","version":"2.1.78","gitBranch":"hotfix","slug":"bright-wandering-flurry"} +{"parentUuid":"d7fab323-a367-483e-8897-11ee79478d84","isSidechain":false,"promptId":"6e6c2140-4cee-4dea-b053-88ef3746e514","type":"user","message":{"role":"user","content":[{"tool_use_id":"toolu_018nSgsu8wqMZNcFMa48KFww","type":"tool_result","content":"No files found"}]},"uuid":"52e02d8c-a064-424b-95f1-51752a46f3d6","timestamp":"2026-03-18T05:09:04.597Z","toolUseResult":{"mode":"files_with_matches","filenames":[],"numFiles":0},"sourceToolAssistantUUID":"d7fab323-a367-483e-8897-11ee79478d84","userType":"external","entrypoint":"cli","cwd":"/Users/jan/prg/ClusterCockpit/cc-backend","sessionId":"5eb20a94-f8df-4979-a0ae-2aa99bfad884","version":"2.1.78","gitBranch":"hotfix","slug":"bright-wandering-flurry"} +{"parentUuid":"52e02d8c-a064-424b-95f1-51752a46f3d6","isSidechain":false,"message":{"model":"claude-opus-4-6","id":"msg_01351VfZ7JY7eQMgUXMKUAHh","type":"message","role":"assistant","content":[{"type":"text","text":"Good, no existing drop tracking. Now let me implement all four changes.\n\n**Change 1:** Use `Keys.NumWorkers` and increase channel buffer in `ReceiveNats`."}],"stop_reason":null,"stop_sequence":null,"usage":{"input_tokens":1,"cache_creation_input_tokens":168,"cache_read_input_tokens":50364,"cache_creation":{"ephemeral_5m_input_tokens":0,"ephemeral_1h_input_tokens":168},"output_tokens":1,"service_tier":"standard","inference_geo":"not_available"}},"requestId":"req_011CZ9y6mJ1XXNAQekSfccWy","type":"assistant","uuid":"c9fb77b4-e95b-4f6b-a7ad-61df9769a06f","timestamp":"2026-03-18T05:09:09.412Z","userType":"external","entrypoint":"cli","cwd":"/Users/jan/prg/ClusterCockpit/cc-backend","sessionId":"5eb20a94-f8df-4979-a0ae-2aa99bfad884","version":"2.1.78","gitBranch":"hotfix","slug":"bright-wandering-flurry"} +{"parentUuid":"c9fb77b4-e95b-4f6b-a7ad-61df9769a06f","isSidechain":false,"message":{"model":"claude-opus-4-6","id":"msg_01351VfZ7JY7eQMgUXMKUAHh","type":"message","role":"assistant","content":[{"type":"tool_use","id":"toolu_01P3haypbU8nxhWoZoC4U8Bp","name":"Edit","input":{"replace_all":false,"file_path":"/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/metricstore.go","old_string":"\t\terr = ReceiveNats(ms, 1, ctx)","new_string":"\t\terr = ReceiveNats(ms, Keys.NumWorkers, ctx)"},"caller":{"type":"direct"}}],"stop_reason":"tool_use","stop_sequence":null,"usage":{"input_tokens":1,"cache_creation_input_tokens":168,"cache_read_input_tokens":50364,"output_tokens":192,"server_tool_use":{"web_search_requests":0,"web_fetch_requests":0},"service_tier":"standard","cache_creation":{"ephemeral_1h_input_tokens":168,"ephemeral_5m_input_tokens":0},"inference_geo":"","iterations":[],"speed":"standard"}},"requestId":"req_011CZ9y6mJ1XXNAQekSfccWy","type":"assistant","uuid":"ac09d096-c6a6-4deb-ab9e-9b8a0e8af0c4","timestamp":"2026-03-18T05:09:10.332Z","userType":"external","entrypoint":"cli","cwd":"/Users/jan/prg/ClusterCockpit/cc-backend","sessionId":"5eb20a94-f8df-4979-a0ae-2aa99bfad884","version":"2.1.78","gitBranch":"hotfix","slug":"bright-wandering-flurry"} +{"type":"file-history-snapshot","messageId":"ac09d096-c6a6-4deb-ab9e-9b8a0e8af0c4","snapshot":{"messageId":"dc9d1865-6087-4cef-b483-1acd956b7f10","trackedFileBackups":{"pkg/metricstore/metricstore.go":{"backupFileName":"9d6c8b589b687438@v1","version":1,"backupTime":"2026-03-18T05:09:10.337Z"}},"timestamp":"2026-03-18T05:08:42.902Z"},"isSnapshotUpdate":true} +{"parentUuid":"ac09d096-c6a6-4deb-ab9e-9b8a0e8af0c4","isSidechain":false,"type":"progress","data":{"type":"hook_progress","hookEvent":"PostToolUse","hookName":"PostToolUse:Edit","command":"callback"},"parentToolUseID":"toolu_01P3haypbU8nxhWoZoC4U8Bp","toolUseID":"toolu_01P3haypbU8nxhWoZoC4U8Bp","timestamp":"2026-03-18T05:09:10.342Z","uuid":"923ff8fe-cf57-49dc-9e5d-c6e152e3bde2","userType":"external","entrypoint":"cli","cwd":"/Users/jan/prg/ClusterCockpit/cc-backend","sessionId":"5eb20a94-f8df-4979-a0ae-2aa99bfad884","version":"2.1.78","gitBranch":"hotfix","slug":"bright-wandering-flurry"} +{"parentUuid":"ac09d096-c6a6-4deb-ab9e-9b8a0e8af0c4","isSidechain":false,"promptId":"6e6c2140-4cee-4dea-b053-88ef3746e514","type":"user","message":{"role":"user","content":[{"tool_use_id":"toolu_01P3haypbU8nxhWoZoC4U8Bp","type":"tool_result","content":"The file /Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/metricstore.go has been updated successfully."}]},"uuid":"045a0dca-c3c4-4ca2-9b41-ec15b9709762","timestamp":"2026-03-18T05:09:10.341Z","toolUseResult":{"filePath":"/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/metricstore.go","oldString":"\t\terr = ReceiveNats(ms, 1, ctx)","newString":"\t\terr = ReceiveNats(ms, Keys.NumWorkers, ctx)","originalFile":"// Copyright (C) NHR@FAU, University Erlangen-Nuremberg.\n// All rights reserved. This file is part of cc-backend.\n// Use of this source code is governed by a MIT-style\n// license that can be found in the LICENSE file.\n\n// Package metricstore provides an efficient in-memory time-series metric storage system\n// with support for hierarchical data organization, checkpointing, and archiving.\n//\n// The package organizes metrics in a tree structure (cluster → host → component) and\n// provides concurrent read/write access to metric data with configurable aggregation strategies.\n// Background goroutines handle periodic checkpointing (JSON or Avro format), archiving old data,\n// and enforcing retention policies.\n//\n// Key features:\n// - In-memory metric storage with configurable retention\n// - Hierarchical data organization (selectors)\n// - Concurrent checkpoint/archive workers\n// - Support for sum and average aggregation\n// - NATS integration for metric ingestion\npackage metricstore\n\nimport (\n\t\"bytes\"\n\t\"context\"\n\t\"encoding/json\"\n\t\"errors\"\n\t\"fmt\"\n\t\"runtime\"\n\t\"runtime/debug\"\n\t\"slices\"\n\t\"sync\"\n\t\"time\"\n\n\t\"github.com/ClusterCockpit/cc-backend/internal/config\"\n\tcclog \"github.com/ClusterCockpit/cc-lib/v2/ccLogger\"\n\t\"github.com/ClusterCockpit/cc-lib/v2/resampler\"\n\t\"github.com/ClusterCockpit/cc-lib/v2/schema\"\n\t\"github.com/ClusterCockpit/cc-lib/v2/util\"\n)\n\n// GlobalState holds the global state for the metric store with thread-safe access.\ntype GlobalState struct {\n\tmu sync.RWMutex\n\tlastRetentionTime int64\n\tselectorsExcluded bool\n}\n\nvar (\n\tsingleton sync.Once\n\tmsInstance *MemoryStore\n\t// shutdownFunc stores the context cancellation function created in Init\n\t// and is called during Shutdown to cancel all background goroutines\n\tshutdownFunc context.CancelFunc\n\tshutdownFuncMu sync.Mutex // Protects shutdownFunc from concurrent access\n\t// Create a global instance\n\tstate = &GlobalState{}\n)\n\n// NodeProvider provides information about nodes currently in use by running jobs.\n//\n// This interface allows metricstore to query job information without directly\n// depending on the repository package, breaking the import cycle.\n//\n// Implementations should return nodes that are actively processing jobs started\n// before the given timestamp. These nodes will be excluded from retention-based\n// garbage collection to prevent data loss for jobs that are still running or\n// recently completed.\ntype NodeProvider interface {\n\t// GetUsedNodes returns a map of cluster names to sorted lists of unique hostnames\n\t// that are currently in use by jobs that started before the given timestamp.\n\t//\n\t// Parameters:\n\t// - ts: Unix timestamp threshold - returns nodes with jobs started before this time\n\t//\n\t// Returns:\n\t// - Map of cluster names to lists of node hostnames that should be excluded from garbage collection\n\t// - Error if the query fails\n\tGetUsedNodes(ts int64) (map[string][]string, error)\n}\n\n// Metric represents a single metric data point to be written to the store.\ntype Metric struct {\n\tName string\n\tValue schema.Float\n\t// MetricConfig contains frequency and aggregation settings for this metric.\n\t// If Frequency is 0, configuration will be looked up from MemoryStore.Metrics during Write().\n\tMetricConfig MetricConfig\n}\n\n// MemoryStore is the main in-memory time-series metric storage implementation.\n//\n// It organizes metrics in a hierarchical tree structure where each level represents\n// a component of the system hierarchy (e.g., cluster → host → CPU). Each level can\n// store multiple metrics as time-series buffers.\n//\n// The store is initialized as a singleton via InitMetrics() and accessed via GetMemoryStore().\n// All public methods are safe for concurrent use.\ntype MemoryStore struct {\n\tMetrics map[string]MetricConfig\n\troot Level\n\tnodeProvider NodeProvider\n}\n\n// Init initializes the metric store from configuration and starts background workers.\n//\n// This function must be called exactly once before any other metricstore operations.\n// It performs the following initialization steps:\n// 1. Validates and decodes the metric store configuration\n// 2. Configures worker pool size (defaults to NumCPU/2+1, max 10)\n// 3. Loads metric configurations from all registered clusters\n// 4. Restores checkpoints within the retention window\n// 5. Starts background workers for retention, checkpointing, archiving, and monitoring\n// 6. Optionally subscribes to NATS for real-time metric ingestion\n//\n// Parameters:\n// - rawConfig: JSON configuration for the metric store (see MetricStoreConfig)\n// - wg: WaitGroup that will be incremented for each background goroutine started\n//\n// The function will call cclog.Fatal on critical errors during initialization.\n// Use Shutdown() to cleanly stop all background workers started by Init().\n//\n// Note: Signal handling must be implemented by the caller. Call Shutdown() when\n// receiving termination signals to ensure checkpoint data is persisted.\nfunc Init(rawConfig json.RawMessage, metrics map[string]MetricConfig, wg *sync.WaitGroup) {\n\tstartupTime := time.Now()\n\n\tif rawConfig != nil {\n\t\tconfig.Validate(configSchema, rawConfig)\n\t\tdec := json.NewDecoder(bytes.NewReader(rawConfig))\n\t\tdec.DisallowUnknownFields()\n\t\tif err := dec.Decode(&Keys); err != nil {\n\t\t\tcclog.Abortf(\"[METRICSTORE]> Metric Store Config Init: Could not decode config file '%s'.\\nError: %s\\n\", rawConfig, err.Error())\n\t\t}\n\t}\n\n\t// Set NumWorkers from config or use default\n\tif Keys.NumWorkers <= 0 {\n\t\tKeys.NumWorkers = min(runtime.NumCPU()/2+1, DefaultMaxWorkers)\n\t}\n\tcclog.Debugf(\"[METRICSTORE]> Using %d workers for checkpoint/archive operations\\n\", Keys.NumWorkers)\n\n\t// Pass the config.MetricStoreKeys\n\tInitMetrics(metrics)\n\n\tms := GetMemoryStore()\n\n\td, err := time.ParseDuration(Keys.RetentionInMemory)\n\tif err != nil {\n\t\tcclog.Fatal(err)\n\t}\n\n\trestoreFrom := startupTime.Add(-d)\n\tcclog.Infof(\"[METRICSTORE]> Loading checkpoints newer than %s\\n\", restoreFrom.Format(time.RFC3339))\n\tfiles, err := ms.FromCheckpointFiles(Keys.Checkpoints.RootDir, restoreFrom.Unix())\n\tloadedData := ms.SizeInBytes() / 1024 / 1024 // In MB\n\tif err != nil {\n\t\tcclog.Fatalf(\"[METRICSTORE]> Loading checkpoints failed: %s\\n\", err.Error())\n\t} else {\n\t\tcclog.Infof(\"[METRICSTORE]> Checkpoints loaded (%d files, %d MB, that took %fs)\\n\", files, loadedData, time.Since(startupTime).Seconds())\n\t}\n\n\t// Try to use less memory by forcing a GC run here and then\n\t// lowering the target percentage. The default of 100 means\n\t// that only once the ratio of new allocations execeds the\n\t// previously active heap, a GC is triggered.\n\t// Forcing a GC here will set the \"previously active heap\"\n\t// to a minumum.\n\t// runtime.GC()\n\n\tctx, shutdown := context.WithCancel(context.Background())\n\n\tRetention(wg, ctx)\n\tCheckpointing(wg, ctx)\n\tCleanUp(wg, ctx)\n\tWALStaging(wg, ctx)\n\tMemoryUsageTracker(wg, ctx)\n\n\t// Note: Signal handling has been removed from this function.\n\t// The caller is responsible for handling shutdown signals and calling\n\t// the shutdown() function when appropriate.\n\t// Store the shutdown function for later use by Shutdown()\n\tshutdownFuncMu.Lock()\n\tshutdownFunc = shutdown\n\tshutdownFuncMu.Unlock()\n\n\tif Keys.Subscriptions != nil {\n\t\terr = ReceiveNats(ms, 1, ctx)\n\t\tif err != nil {\n\t\t\tcclog.Fatal(err)\n\t\t}\n\t}\n}\n\n// InitMetrics initializes the singleton MemoryStore instance with the given metric configurations.\n//\n// This function must be called before GetMemoryStore() and can only be called once due to\n// the singleton pattern. It assigns each metric an internal offset for efficient buffer indexing.\n//\n// Parameters:\n// - metrics: Map of metric names to their configurations (frequency and aggregation strategy)\n//\n// Panics if any metric has Frequency == 0, which indicates an invalid configuration.\n//\n// After this call, the global msInstance is ready for use via GetMemoryStore().\nfunc InitMetrics(metrics map[string]MetricConfig) {\n\tsingleton.Do(func() {\n\t\toffset := 0\n\t\tfor key, cfg := range metrics {\n\t\t\tif cfg.Frequency == 0 {\n\t\t\t\tpanic(\"[METRICSTORE]> invalid frequency\")\n\t\t\t}\n\n\t\t\tmetrics[key] = MetricConfig{\n\t\t\t\tFrequency: cfg.Frequency,\n\t\t\t\tAggregation: cfg.Aggregation,\n\t\t\t\toffset: offset,\n\t\t\t}\n\t\t\toffset += 1\n\t\t}\n\n\t\tmsInstance = &MemoryStore{\n\t\t\troot: Level{\n\t\t\t\tmetrics: make([]*buffer, len(metrics)),\n\t\t\t\tchildren: make(map[string]*Level),\n\t\t\t},\n\t\t\tMetrics: metrics,\n\t\t}\n\t})\n}\n\n// GetMemoryStore returns the singleton MemoryStore instance.\n//\n// Returns the initialized MemoryStore singleton. Calls cclog.Fatal if InitMetrics() was not called first.\n//\n// This function is safe for concurrent use after initialization.\nfunc GetMemoryStore() *MemoryStore {\n\tif msInstance == nil {\n\t\tcclog.Warnf(\"[METRICSTORE]> MemoryStore not initialized!\")\n\t}\n\n\treturn msInstance\n}\n\nfunc (ms *MemoryStore) GetMetricFrequency(metricName string) (int64, error) {\n\tif metric, ok := ms.Metrics[metricName]; ok {\n\t\treturn metric.Frequency, nil\n\t}\n\treturn 0, fmt.Errorf(\"[METRICSTORE]> metric %s not found\", metricName)\n}\n\n// SetNodeProvider sets the NodeProvider implementation for the MemoryStore.\n// This must be called during initialization to provide job state information\n// for selective buffer retention during Free operations.\n// If not set, the Free function will fall back to freeing all buffers.\nfunc (ms *MemoryStore) SetNodeProvider(provider NodeProvider) {\n\tms.nodeProvider = provider\n}\n\n// Shutdown performs a graceful shutdown of the metric store.\n//\n// This function cancels all background goroutines started by Init() and writes\n// a final checkpoint to disk before returning. It should be called when the\n// application receives a termination signal.\n//\n// The function will:\n// 1. Cancel the context to stop all background workers\n// 2. Close the WAL messages channel if using WAL format\n// 3. Write a final checkpoint to preserve in-memory data\n// 4. Log any errors encountered during shutdown\n//\n// Note: This function blocks until the final checkpoint is written.\nfunc Shutdown() {\n\tshutdownFuncMu.Lock()\n\tdefer shutdownFuncMu.Unlock()\n\tif shutdownFunc != nil {\n\t\tshutdownFunc()\n\t}\n\n\tif Keys.Checkpoints.FileFormat == \"wal\" {\n\t\tclose(WALMessages)\n\t}\n\n\tcclog.Infof(\"[METRICSTORE]> Writing to '%s'...\\n\", Keys.Checkpoints.RootDir)\n\tvar files int\n\tvar err error\n\n\tms := GetMemoryStore()\n\n\tlastCheckpointMu.Lock()\n\tfrom := lastCheckpoint\n\tlastCheckpointMu.Unlock()\n\n\tif Keys.Checkpoints.FileFormat == \"wal\" {\n\t\tvar hostDirs []string\n\t\tfiles, hostDirs, err = ms.ToCheckpointWAL(Keys.Checkpoints.RootDir, from.Unix(), time.Now().Unix())\n\t\tif err == nil {\n\t\t\tRotateWALFilesAfterShutdown(hostDirs)\n\t\t}\n\t} else {\n\t\tfiles, err = ms.ToCheckpoint(Keys.Checkpoints.RootDir, from.Unix(), time.Now().Unix())\n\t}\n\n\tif err != nil {\n\t\tcclog.Errorf(\"[METRICSTORE]> Writing checkpoint failed: %s\\n\", err.Error())\n\t}\n\tcclog.Infof(\"[METRICSTORE]> Done! (%d files written)\\n\", files)\n}\n\n// Retention starts a background goroutine that periodically frees old metric data.\n//\n// This worker runs at half the retention interval and calls Free() to remove buffers\n// older than the configured retention time. It respects the NodeProvider to preserve\n// data for nodes with active jobs.\n//\n// Parameters:\n// - wg: WaitGroup to signal completion when context is cancelled\n// - ctx: Context for cancellation signal\n//\n// The goroutine exits when ctx is cancelled.\nfunc Retention(wg *sync.WaitGroup, ctx context.Context) {\n\tms := GetMemoryStore()\n\n\twg.Go(func() {\n\t\td, err := time.ParseDuration(Keys.RetentionInMemory)\n\t\tif err != nil {\n\t\t\tcclog.Fatal(err)\n\t\t}\n\t\tif d <= 0 {\n\t\t\treturn\n\t\t}\n\n\t\ttickInterval := d / 2\n\t\tif tickInterval <= 0 {\n\t\t\treturn\n\t\t}\n\t\tticker := time.NewTicker(tickInterval)\n\t\tdefer ticker.Stop()\n\n\t\tfor {\n\t\t\tselect {\n\t\t\tcase <-ctx.Done():\n\t\t\t\treturn\n\t\t\tcase <-ticker.C:\n\t\t\t\tstate.mu.Lock()\n\n\t\t\t\tt := time.Now().Add(-d)\n\n\t\t\t\tstate.lastRetentionTime = t.Unix()\n\n\t\t\t\tcclog.Infof(\"[METRICSTORE]> start freeing buffers (older than %s)...\\n\", t.Format(time.RFC3339))\n\n\t\t\t\tfreed, err := Free(ms, t)\n\t\t\t\tif err != nil {\n\t\t\t\t\tcclog.Errorf(\"[METRICSTORE]> freeing up buffers failed: %s\\n\", err.Error())\n\t\t\t\t} else {\n\t\t\t\t\tcclog.Infof(\"[METRICSTORE]> done: %d buffers freed\\n\", freed)\n\t\t\t\t}\n\n\t\t\t\tstate.mu.Unlock()\n\n\t\t\t\t// Clean up the buffer pool\n\t\t\t\tbufferPool.Clean(state.lastRetentionTime)\n\t\t\t}\n\t\t}\n\t})\n}\n\n// MemoryUsageTracker starts a background goroutine that monitors memory usage.\n//\n// This worker checks actual process memory usage (via runtime.MemStats) periodically\n// and force-frees buffers if memory exceeds the configured cap. It uses FreeOSMemory()\n// to return memory to the OS after freeing buffers, avoiding aggressive GC that causes\n// performance issues.\n//\n// The tracker logs both actual memory usage (heap allocated) and metric data size for\n// visibility into memory overhead from Go runtime structures and allocations.\n//\n// Parameters:\n// - wg: WaitGroup to signal completion when context is cancelled\n// - ctx: Context for cancellation signal\n//\n// The goroutine exits when ctx is cancelled.\nfunc MemoryUsageTracker(wg *sync.WaitGroup, ctx context.Context) {\n\tms := GetMemoryStore()\n\n\twg.Go(func() {\n\t\tnormalInterval := DefaultMemoryUsageTrackerInterval\n\t\tfastInterval := 30 * time.Second\n\n\t\tif normalInterval <= 0 {\n\t\t\treturn\n\t\t}\n\n\t\tticker := time.NewTicker(normalInterval)\n\t\tdefer ticker.Stop()\n\t\tcurrentInterval := normalInterval\n\n\t\tfor {\n\t\t\tselect {\n\t\t\tcase <-ctx.Done():\n\t\t\t\treturn\n\t\t\tcase <-ticker.C:\n\t\t\t\tvar mem runtime.MemStats\n\t\t\t\truntime.ReadMemStats(&mem)\n\t\t\t\tactualMemoryGB := float64(mem.Alloc) / 1e9\n\t\t\t\tmetricDataGB := ms.SizeInGB()\n\t\t\t\tcclog.Infof(\"[METRICSTORE]> memory usage: %.2f GB actual (%.2f GB metric data)\", actualMemoryGB, metricDataGB)\n\n\t\t\t\tfreedExcluded := 0\n\t\t\t\tfreedEmergency := 0\n\t\t\t\tvar err error\n\n\t\t\t\tstate.mu.RLock()\n\t\t\t\tlastRetention := state.lastRetentionTime\n\t\t\t\tselectorsExcluded := state.selectorsExcluded\n\t\t\t\tstate.mu.RUnlock()\n\n\t\t\t\tif lastRetention != 0 && selectorsExcluded {\n\t\t\t\t\tfreedExcluded, err = ms.Free(nil, lastRetention)\n\t\t\t\t\tif err != nil {\n\t\t\t\t\t\tcclog.Errorf(\"[METRICSTORE]> error while force-freeing the excluded buffers: %s\", err)\n\t\t\t\t\t}\n\n\t\t\t\t\tif freedExcluded > 0 {\n\t\t\t\t\t\tdebug.FreeOSMemory()\n\t\t\t\t\t\tcclog.Infof(\"[METRICSTORE]> done: %d excluded buffers force-freed\", freedExcluded)\n\t\t\t\t\t}\n\t\t\t\t}\n\n\t\t\t\truntime.ReadMemStats(&mem)\n\t\t\t\tactualMemoryGB = float64(mem.Alloc) / 1e9\n\n\t\t\t\tif actualMemoryGB > float64(Keys.MemoryCap) {\n\t\t\t\t\tcclog.Warnf(\"[METRICSTORE]> memory usage %.2f GB exceeds cap %d GB, starting emergency buffer freeing\", actualMemoryGB, Keys.MemoryCap)\n\n\t\t\t\t\t// Use progressive time-based Free with increasing threshold\n\t\t\t\t\t// instead of ForceFree loop — fewer tree traversals, more effective\n\t\t\t\t\td, parseErr := time.ParseDuration(Keys.RetentionInMemory)\n\t\t\t\t\tif parseErr != nil {\n\t\t\t\t\t\tcclog.Errorf(\"[METRICSTORE]> cannot parse retention duration: %s\", parseErr)\n\t\t\t\t\t} else {\n\t\t\t\t\t\tthresholds := []float64{0.75, 0.5, 0.25}\n\t\t\t\t\t\tfor _, fraction := range thresholds {\n\t\t\t\t\t\t\tthreshold := time.Now().Add(-time.Duration(float64(d) * fraction))\n\t\t\t\t\t\t\tfreed, freeErr := ms.Free(nil, threshold.Unix())\n\t\t\t\t\t\t\tif freeErr != nil {\n\t\t\t\t\t\t\t\tcclog.Errorf(\"[METRICSTORE]> error while freeing buffers at %.0f%% retention: %s\", fraction*100, freeErr)\n\t\t\t\t\t\t\t}\n\t\t\t\t\t\t\tfreedEmergency += freed\n\n\t\t\t\t\t\t\tbufferPool.Clear()\n\t\t\t\t\t\t\truntime.GC()\n\t\t\t\t\t\t\truntime.ReadMemStats(&mem)\n\t\t\t\t\t\t\tactualMemoryGB = float64(mem.Alloc) / 1e9\n\n\t\t\t\t\t\t\tif actualMemoryGB < float64(Keys.MemoryCap) {\n\t\t\t\t\t\t\t\tbreak\n\t\t\t\t\t\t\t}\n\t\t\t\t\t\t}\n\t\t\t\t\t}\n\n\t\t\t\t\tbufferPool.Clear()\n\t\t\t\t\tdebug.FreeOSMemory()\n\n\t\t\t\t\truntime.ReadMemStats(&mem)\n\t\t\t\t\tactualMemoryGB = float64(mem.Alloc) / 1e9\n\n\t\t\t\t\tif actualMemoryGB >= float64(Keys.MemoryCap) {\n\t\t\t\t\t\tcclog.Errorf(\"[METRICSTORE]> after emergency frees (%d buffers), memory usage %.2f GB still at/above cap %d GB\", freedEmergency, actualMemoryGB, Keys.MemoryCap)\n\t\t\t\t\t} else {\n\t\t\t\t\t\tcclog.Infof(\"[METRICSTORE]> emergency freeing complete: %d buffers freed, memory now %.2f GB\", freedEmergency, actualMemoryGB)\n\t\t\t\t\t}\n\t\t\t\t}\n\n\t\t\t\t// Adaptive ticker: check more frequently when memory is high\n\t\t\t\tmemoryRatio := actualMemoryGB / float64(Keys.MemoryCap)\n\t\t\t\tif memoryRatio > 0.8 && currentInterval != fastInterval {\n\t\t\t\t\tticker.Reset(fastInterval)\n\t\t\t\t\tcurrentInterval = fastInterval\n\t\t\t\t\tcclog.Infof(\"[METRICSTORE]> memory at %.0f%% of cap, switching to fast check interval (30s)\", memoryRatio*100)\n\t\t\t\t} else if memoryRatio <= 0.8 && currentInterval != normalInterval {\n\t\t\t\t\tticker.Reset(normalInterval)\n\t\t\t\t\tcurrentInterval = normalInterval\n\t\t\t\t\tcclog.Infof(\"[METRICSTORE]> memory at %.0f%% of cap, switching to normal check interval\", memoryRatio*100)\n\t\t\t\t}\n\t\t\t}\n\t\t}\n\t})\n}\n\n// Free removes metric data older than the given time while preserving data for active nodes.\n//\n// This function implements intelligent retention by consulting the NodeProvider (if configured)\n// to determine which nodes are currently in use by running jobs. Data for these nodes is\n// preserved even if older than the retention time.\n//\n// Parameters:\n// - ms: The MemoryStore instance\n// - t: Time threshold - buffers with data older than this will be freed\n//\n// Returns:\n// - Number of buffers freed\n// - Error if NodeProvider query fails\n//\n// Behavior:\n// - If no NodeProvider is set: frees all buffers older than t\n// - If NodeProvider returns empty map: frees all buffers older than t\n// - Otherwise: preserves buffers for nodes returned by GetUsedNodes(), frees others\nfunc Free(ms *MemoryStore, t time.Time) (int, error) {\n\t// If no NodeProvider is configured, free all buffers older than t\n\tif ms.nodeProvider == nil {\n\t\treturn ms.Free(nil, t.Unix())\n\t}\n\n\texcludeSelectors, err := ms.nodeProvider.GetUsedNodes(t.Unix())\n\tif err != nil {\n\t\treturn 0, err\n\t}\n\n\tswitch lenMap := len(excludeSelectors); lenMap {\n\n\t// If the length of the map returned by GetUsedNodes() is 0,\n\t// then use default Free method with nil selector\n\tcase 0:\n\t\tstate.selectorsExcluded = false\n\t\treturn ms.Free(nil, t.Unix())\n\n\t// Else formulate selectors, exclude those from the map\n\t// and free the rest of the selectors\n\tdefault:\n\t\tstate.selectorsExcluded = true\n\t\tselectors := GetSelectors(ms, excludeSelectors)\n\t\treturn FreeSelected(ms, selectors, t)\n\t}\n}\n\n// FreeSelected frees buffers for specific selectors while preserving others.\n//\n// This function is used when we want to retain some specific nodes beyond the retention time.\n// It iterates through the provided selectors and frees their associated buffers.\n//\n// Parameters:\n// - ms: The MemoryStore instance\n// - selectors: List of selector paths to free (e.g., [[\"cluster1\", \"node1\"], [\"cluster2\", \"node2\"]])\n// - t: Time threshold for freeing buffers\n//\n// Returns the total number of buffers freed and any error encountered.\nfunc FreeSelected(ms *MemoryStore, selectors [][]string, t time.Time) (int, error) {\n\tfreed := 0\n\n\tfor _, selector := range selectors {\n\n\t\tfreedBuffers, err := ms.Free(selector, t.Unix())\n\t\tif err != nil {\n\t\t\tcclog.Errorf(\"error while freeing selected buffers: %#v\", err)\n\t\t}\n\t\tfreed += freedBuffers\n\n\t}\n\n\treturn freed, nil\n}\n\n// GetSelectors returns all selectors at depth 2 (cluster/node level) that are NOT in the exclusion map.\n//\n// This function generates a list of selectors whose buffers should be freed by excluding\n// selectors that correspond to nodes currently in use by running jobs.\n//\n// Parameters:\n// - ms: The MemoryStore instance\n// - excludeSelectors: Map of cluster names to node hostnames that should NOT be freed\n//\n// Returns a list of selectors ([]string paths) that can be safely freed.\n//\n// Example:\n//\n//\tIf the tree has paths [\"emmy\", \"node001\"] and [\"emmy\", \"node002\"],\n//\tand excludeSelectors contains {\"emmy\": [\"node001\"]},\n//\tthen only [[\"emmy\", \"node002\"]] is returned.\nfunc GetSelectors(ms *MemoryStore, excludeSelectors map[string][]string) [][]string {\n\tallSelectors := ms.GetPaths(2)\n\n\tfilteredSelectors := make([][]string, 0, len(allSelectors))\n\n\tfor _, path := range allSelectors {\n\t\tif len(path) < 2 {\n\t\t\tcontinue\n\t\t}\n\n\t\tkey := path[0] // The \"Key\" (Level 1)\n\t\tvalue := path[1] // The \"Value\" (Level 2)\n\n\t\texclude := false\n\n\t\t// Check if the key exists in our exclusion map\n\t\tif excludedValues, exists := excludeSelectors[key]; exists {\n\t\t\t// The key exists, now check if the specific value is in the exclusion list\n\t\t\tif slices.Contains(excludedValues, value) {\n\t\t\t\texclude = true\n\t\t\t}\n\t\t}\n\n\t\tif !exclude {\n\t\t\tfilteredSelectors = append(filteredSelectors, path)\n\t\t}\n\t}\n\n\treturn filteredSelectors\n}\n\n// GetPaths returns a list of lists (paths) to the specified depth.\nfunc (ms *MemoryStore) GetPaths(targetDepth int) [][]string {\n\tvar results [][]string\n\n\t// Start recursion. Initial path is empty.\n\t// We treat Root as depth 0.\n\tms.root.collectPaths(0, targetDepth, []string{}, &results)\n\n\treturn results\n}\n\n// Write all values in `metrics` to the level specified by `selector` for time `ts`.\n// Look at `findLevelOrCreate` for how selectors work.\nfunc (m *MemoryStore) Write(selector []string, ts int64, metrics []Metric) error {\n\tvar ok bool\n\tfor i, metric := range metrics {\n\t\tif metric.MetricConfig.Frequency == 0 {\n\t\t\tmetric.MetricConfig, ok = m.Metrics[metric.Name]\n\t\t\tif !ok {\n\t\t\t\tcclog.Debugf(\"[METRICSTORE]> Unknown metric '%s' in Write() - skipping\", metric.Name)\n\t\t\t\tmetric.MetricConfig.Frequency = 0\n\t\t\t}\n\t\t\tmetrics[i] = metric\n\t\t}\n\t}\n\n\treturn m.WriteToLevel(&m.root, selector, ts, metrics)\n}\n\nfunc (m *MemoryStore) GetLevel(selector []string) *Level {\n\treturn m.root.findLevelOrCreate(selector, len(m.Metrics))\n}\n\n// WriteToLevel assumes that `minfo` in `metrics` is filled in\nfunc (m *MemoryStore) WriteToLevel(l *Level, selector []string, ts int64, metrics []Metric) error {\n\tl = l.findLevelOrCreate(selector, len(m.Metrics))\n\tl.lock.Lock()\n\tdefer l.lock.Unlock()\n\n\tfor _, metric := range metrics {\n\t\tif metric.MetricConfig.Frequency == 0 {\n\t\t\tcontinue\n\t\t}\n\n\t\tb := l.metrics[metric.MetricConfig.offset]\n\t\tif b == nil {\n\t\t\t// First write to this metric and level\n\t\t\tb = newBuffer(ts, metric.MetricConfig.Frequency)\n\t\t\tl.metrics[metric.MetricConfig.offset] = b\n\t\t}\n\n\t\tnb, err := b.write(ts, metric.Value)\n\t\tif err != nil {\n\t\t\treturn err\n\t\t}\n\n\t\t// Last write created a new buffer...\n\t\tif b != nb {\n\t\t\tl.metrics[metric.MetricConfig.offset] = nb\n\t\t}\n\t}\n\treturn nil\n}\n\n// Read returns all values for metric `metric` from `from` to `to` for the selected level(s).\n// If the level does not hold the metric itself, the data will be aggregated recursively from the children.\n// The second and third return value are the actual from/to for the data. Those can be different from\n// the range asked for if no data was available.\nfunc (m *MemoryStore) Read(selector util.Selector, metric string, from, to, resolution int64) ([]schema.Float, int64, int64, int64, error) {\n\tif from > to {\n\t\treturn nil, 0, 0, 0, errors.New(\"[METRICSTORE]> invalid time range\")\n\t}\n\n\tminfo, ok := m.Metrics[metric]\n\tif !ok {\n\t\treturn nil, 0, 0, 0, errors.New(\"[METRICSTORE]> unknown metric: \" + metric)\n\t}\n\n\tn, data := 0, make([]schema.Float, (to-from)/minfo.Frequency+1)\n\n\terr := m.root.findBuffers(selector, minfo.offset, func(b *buffer) error {\n\t\tcdata, cfrom, cto, err := b.read(from, to, data)\n\t\tif err != nil {\n\t\t\treturn err\n\t\t}\n\n\t\tif n == 0 {\n\t\t\tfrom, to = cfrom, cto\n\t\t} else if from != cfrom || to != cto || len(data) != len(cdata) {\n\t\t\tmissingfront, missingback := int((from-cfrom)/minfo.Frequency), int((to-cto)/minfo.Frequency)\n\t\t\tif missingfront != 0 {\n\t\t\t\treturn ErrDataDoesNotAlign\n\t\t\t}\n\n\t\t\tnewlen := len(cdata) - missingback\n\t\t\tif newlen < 1 {\n\t\t\t\treturn ErrDataDoesNotAlign\n\t\t\t}\n\t\t\tcdata = cdata[0:newlen]\n\t\t\tif len(cdata) != len(data) {\n\t\t\t\treturn ErrDataDoesNotAlign\n\t\t\t}\n\n\t\t\tfrom, to = cfrom, cto\n\t\t}\n\n\t\tdata = cdata\n\t\tn += 1\n\t\treturn nil\n\t})\n\n\tif err != nil {\n\t\treturn nil, 0, 0, 0, err\n\t} else if n == 0 {\n\t\treturn nil, 0, 0, 0, ErrNoHostOrMetric\n\t} else if n > 1 {\n\t\tif minfo.Aggregation == AvgAggregation {\n\t\t\tnormalize := 1. / schema.Float(n)\n\t\t\tfor i := 0; i < len(data); i++ {\n\t\t\t\tdata[i] *= normalize\n\t\t\t}\n\t\t} else if minfo.Aggregation != SumAggregation {\n\t\t\treturn nil, 0, 0, 0, errors.New(\"[METRICSTORE]> invalid aggregation\")\n\t\t}\n\t}\n\n\tdata, resolution, err = resampler.LargestTriangleThreeBucket(data, minfo.Frequency, resolution)\n\tif err != nil {\n\t\treturn nil, 0, 0, 0, err\n\t}\n\n\treturn data, from, to, resolution, nil\n}\n\n// Free releases all buffers for the selected level and all its children that\n// contain only values older than `t`.\nfunc (m *MemoryStore) Free(selector []string, t int64) (int, error) {\n\treturn m.GetLevel(selector).free(t)\n}\n\n// ForceFree unconditionally removes the oldest buffer from each metric chain.\nfunc (m *MemoryStore) ForceFree() (int, error) {\n\treturn m.GetLevel(nil).forceFree()\n}\n\nfunc (m *MemoryStore) FreeAll() error {\n\tm.root.lock.Lock()\n\tdefer m.root.lock.Unlock()\n\n\tfor k := range m.root.children {\n\t\tdelete(m.root.children, k)\n\t}\n\n\treturn nil\n}\n\nfunc (m *MemoryStore) SizeInBytes() int64 {\n\treturn m.root.sizeInBytes()\n}\n\nfunc (m *MemoryStore) SizeInGB() float64 {\n\treturn float64(m.root.sizeInBytes()) / 1e9\n}\n\n// ListChildren , given a selector, returns a list of all children of the level\n// selected.\nfunc (m *MemoryStore) ListChildren(selector []string) []string {\n\tlvl := &m.root\n\tfor lvl != nil && len(selector) != 0 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This file is part of cc-backend.\n// Use of this source code is governed by a MIT-style\n// license that can be found in the LICENSE file.\n\n// This file implements ingestion of InfluxDB line-protocol metric data received\n// over NATS. Each line encodes one metric sample with the following structure:\n//\n//\t[,cluster=][,hostname=][,type=][,type-id=][,subtype=][,stype-id=] value= []\n//\n// The measurement name identifies the metric (e.g. \"cpu_load\"). Tags provide\n// routing information (cluster, host) and optional sub-device selectors (type,\n// subtype). Only one field is expected per line: \"value\".\n//\n// After decoding, each sample is:\n// 1. Written to the in-memory store via ms.WriteToLevel.\n// 2. If the checkpoint format is \"wal\", also forwarded to the WAL staging\n// goroutine via the WALMessages channel for durable write-ahead logging.\npackage metricstore\n\nimport (\n\t\"bytes\"\n\t\"context\"\n\t\"fmt\"\n\t\"sync\"\n\t\"time\"\n\n\tcclog \"github.com/ClusterCockpit/cc-lib/v2/ccLogger\"\n\t\"github.com/ClusterCockpit/cc-lib/v2/nats\"\n\t\"github.com/ClusterCockpit/cc-lib/v2/schema\"\n\t\"github.com/ClusterCockpit/cc-line-protocol/v2/lineprotocol\"\n)\n\n// ReceiveNats subscribes to all configured NATS subjects and feeds incoming\n// line-protocol messages into the MemoryStore.\n//\n// When workers > 1 a pool of goroutines drains a shared channel so that\n// multiple messages can be decoded in parallel. With workers == 1 the NATS\n// callback decodes inline (no channel overhead, lower latency).\n//\n// The function blocks until ctx is cancelled and all worker goroutines have\n// finished. It returns nil when the NATS client is not configured; callers\n// should treat that as a no-op rather than an error.\nfunc ReceiveNats(ms *MemoryStore,\n\tworkers int,\n\tctx context.Context,\n) error {\n\tnc := nats.GetClient()\n\n\tif nc == nil {\n\t\tcclog.Warn(\"NATS client not initialized\")\n\t\treturn nil\n\t}\n\n\tvar wg sync.WaitGroup\n\tmsgs := make(chan []byte, workers*2)\n\n\tfor _, sc := range *Keys.Subscriptions {\n\t\tclusterTag := sc.ClusterTag\n\t\tif workers > 1 {\n\t\t\twg.Add(workers)\n\n\t\t\tfor range workers {\n\t\t\t\tgo func() {\n\t\t\t\t\tdefer wg.Done()\n\t\t\t\t\tfor m := range msgs {\n\t\t\t\t\t\tdec := lineprotocol.NewDecoderWithBytes(m)\n\t\t\t\t\t\tif err := DecodeLine(dec, ms, clusterTag); err != nil {\n\t\t\t\t\t\t\tcclog.Errorf(\"error: %s\", err.Error())\n\t\t\t\t\t\t}\n\t\t\t\t\t}\n\t\t\t\t}()\n\t\t\t}\n\n\t\t\tnc.Subscribe(sc.SubscribeTo, func(subject string, data []byte) {\n\t\t\t\tselect {\n\t\t\t\tcase msgs <- data:\n\t\t\t\tcase <-ctx.Done():\n\t\t\t\t}\n\t\t\t})\n\t\t} else {\n\t\t\tnc.Subscribe(sc.SubscribeTo, func(subject string, data []byte) {\n\t\t\t\tdec := lineprotocol.NewDecoderWithBytes(data)\n\t\t\t\tif err := DecodeLine(dec, ms, clusterTag); err != nil {\n\t\t\t\t\tcclog.Errorf(\"error: %s\", err.Error())\n\t\t\t\t}\n\t\t\t})\n\t\t}\n\t\tcclog.Infof(\"NATS subscription to '%s' established\", sc.SubscribeTo)\n\t}\n\n\tgo func() {\n\t\t<-ctx.Done()\n\t\tclose(msgs)\n\t}()\n\n\twg.Wait()\n\n\treturn nil\n}\n\n// reorder prepends prefix to buf in-place when buf has enough spare capacity,\n// avoiding an allocation. Falls back to a regular append otherwise.\n//\n// It is used to assemble the \"type\" and \"subtype\" selector\n// strings when the type tag arrives before the type-id tag in the line, so the\n// two byte slices need to be concatenated in tag-declaration order regardless\n// of wire order.\nfunc reorder(buf, prefix []byte) []byte {\n\tn := len(prefix)\n\tm := len(buf)\n\tif cap(buf) < m+n {\n\t\treturn append(prefix[:n:n], buf...)\n\t} else {\n\t\tbuf = buf[:n+m]\n\t\tfor i := m - 1; i >= 0; i-- {\n\t\t\tbuf[i+n] = buf[i]\n\t\t}\n\t\tfor i := range n {\n\t\t\tbuf[i] = prefix[i]\n\t\t}\n\t\treturn buf\n\t}\n}\n\n// decodeState holds the per-call scratch buffers used by DecodeLine.\n// Instances are recycled via decodeStatePool to avoid repeated allocations\n// during high-throughput ingestion.\ntype decodeState struct {\n\t// metricBuf holds a copy of the current measurement name (line-protocol\n\t// measurement field). Copied because dec.Measurement() returns a slice\n\t// that is invalidated by the next decoder call.\n\tmetricBuf []byte\n\n\t// selector is the sub-device path passed to WriteToLevel and WALMessage\n\t// (e.g. [\"socket0\"] or [\"socket0\", \"memctrl1\"]). Reused across lines.\n\tselector []string\n\n\t// typeBuf accumulates the concatenated \"type\"+\"type-id\" tag value for the\n\t// current line. Reset at the start of each line's tag-decode loop.\n\ttypeBuf []byte\n\n\t// subTypeBuf accumulates the concatenated \"subtype\"+\"stype-id\" tag value.\n\t// Reset at the start of each line's tag-decode loop.\n\tsubTypeBuf []byte\n\n\t// prevTypeBytes / prevTypeStr cache the last seen typeBuf content and its\n\t// string conversion. Because consecutive lines in a batch typically address\n\t// the same sub-device, the cache hit rate is very high and avoids\n\t// repeated []byte→string allocations.\n\tprevTypeBytes []byte\n\tprevTypeStr string\n\n\t// prevSubTypeBytes / prevSubTypeStr are the same cache for the subtype.\n\tprevSubTypeBytes []byte\n\tprevSubTypeStr string\n}\n\n// decodeStatePool recycles decodeState values across DecodeLine calls to\n// reduce GC pressure during sustained metric ingestion.\nvar decodeStatePool = sync.Pool{\n\tNew: func() any {\n\t\treturn &decodeState{\n\t\t\tmetricBuf: make([]byte, 0, 16),\n\t\t\tselector: make([]string, 0, 4),\n\t\t\ttypeBuf: make([]byte, 0, 16),\n\t\t\tsubTypeBuf: make([]byte, 0, 16),\n\t\t}\n\t},\n}\n\n// DecodeLine reads all lines from dec (InfluxDB line-protocol) and writes each\n// decoded metric sample into ms.\n//\n// clusterDefault is used as the cluster name for lines that do not carry a\n// \"cluster\" tag. Callers typically supply the ClusterTag value from the NATS\n// subscription configuration.\n//\n// Performance notes:\n// - A decodeState is obtained from decodeStatePool to reuse scratch buffers.\n// - The Level pointer (host-level node in the metric tree) is cached across\n// consecutive lines that share the same cluster+host pair to avoid\n// repeated lock acquisitions on the root and cluster levels.\n// - []byte→string conversions for type/subtype selectors are cached via\n// prevType*/prevSubType* fields because batches typically repeat the same\n// sub-device identifiers.\n// - Timestamp parsing tries Second precision first; if that fails it retries\n// Millisecond, Microsecond, and Nanosecond in turn. A missing timestamp\n// falls back to time.Now().\n//\n// When the checkpoint format is \"wal\" each successfully decoded sample is also\n// sent to WALMessages so the WAL staging goroutine can persist it durably\n// before the next binary snapshot.\nfunc DecodeLine(dec *lineprotocol.Decoder,\n\tms *MemoryStore,\n\tclusterDefault string,\n) error {\n\t// Reduce allocations in loop:\n\tt := time.Now()\n\tmetric := Metric{}\n\tst := decodeStatePool.Get().(*decodeState)\n\tdefer decodeStatePool.Put(st)\n\n\t// Optimize for the case where all lines in a \"batch\" are about the same\n\t// cluster and host. By using `WriteToLevel` (level = host), we do not need\n\t// to take the root- and cluster-level lock as often.\n\tvar lvl *Level = nil\n\tprevCluster, prevHost := \"\", \"\"\n\n\tvar ok bool\n\tfor dec.Next() {\n\t\trawmeasurement, err := dec.Measurement()\n\t\tif err != nil {\n\t\t\treturn err\n\t\t}\n\n\t\t// Needs to be copied because another call to dec.* would\n\t\t// invalidate the returned slice.\n\t\tst.metricBuf = append(st.metricBuf[:0], rawmeasurement...)\n\n\t\t// The go compiler optimizes map[string(byteslice)] lookups:\n\t\tmetric.MetricConfig, ok = ms.Metrics[string(rawmeasurement)]\n\t\tif !ok {\n\t\t\tcontinue\n\t\t}\n\n\t\tst.typeBuf, st.subTypeBuf = st.typeBuf[:0], st.subTypeBuf[:0]\n\t\tcluster, host := clusterDefault, \"\"\n\t\tfor {\n\t\t\tkey, val, err := dec.NextTag()\n\t\t\tif err != nil {\n\t\t\t\treturn err\n\t\t\t}\n\t\t\tif key == nil {\n\t\t\t\tbreak\n\t\t\t}\n\n\t\t\t// The go compiler optimizes string([]byte{...}) == \"...\":\n\t\t\tswitch string(key) {\n\t\t\tcase \"cluster\":\n\t\t\t\tif string(val) == prevCluster {\n\t\t\t\t\tcluster = prevCluster\n\t\t\t\t} else {\n\t\t\t\t\tcluster = string(val)\n\t\t\t\t\tlvl = nil\n\t\t\t\t}\n\t\t\tcase \"hostname\", \"host\":\n\t\t\t\tif string(val) == prevHost {\n\t\t\t\t\thost = prevHost\n\t\t\t\t} else {\n\t\t\t\t\thost = string(val)\n\t\t\t\t\tlvl = nil\n\t\t\t\t}\n\t\t\tcase \"type\":\n\t\t\t\tif string(val) == \"node\" {\n\t\t\t\t\tbreak\n\t\t\t\t}\n\n\t\t\t\t// We cannot be sure that the \"type\" tag comes before the \"type-id\" tag:\n\t\t\t\tif len(st.typeBuf) == 0 {\n\t\t\t\t\tst.typeBuf = append(st.typeBuf, val...)\n\t\t\t\t} else {\n\t\t\t\t\tst.typeBuf = reorder(st.typeBuf, val)\n\t\t\t\t}\n\t\t\tcase \"type-id\":\n\t\t\t\tst.typeBuf = append(st.typeBuf, val...)\n\t\t\tcase \"subtype\":\n\t\t\t\t// We cannot be sure that the \"subtype\" tag comes before the \"stype-id\" tag:\n\t\t\t\tif len(st.subTypeBuf) == 0 {\n\t\t\t\t\tst.subTypeBuf = append(st.subTypeBuf, val...)\n\t\t\t\t} else {\n\t\t\t\t\tst.subTypeBuf = reorder(st.subTypeBuf, val)\n\t\t\t\t}\n\t\t\tcase \"stype-id\":\n\t\t\t\tst.subTypeBuf = append(st.subTypeBuf, val...)\n\t\t\tdefault:\n\t\t\t}\n\t\t}\n\n\t\t// If the cluster or host changed, the lvl was set to nil\n\t\tif lvl == nil {\n\t\t\tst.selector = st.selector[:2]\n\t\t\tst.selector[0], st.selector[1] = cluster, host\n\t\t\tlvl = ms.GetLevel(st.selector)\n\t\t\tprevCluster, prevHost = cluster, host\n\t\t}\n\n\t\t// subtypes: cache []byte→string conversions; messages in a batch typically\n\t\t// share the same type/subtype so the hit rate is very high.\n\t\tst.selector = st.selector[:0]\n\t\tif len(st.typeBuf) > 0 {\n\t\t\tif !bytes.Equal(st.typeBuf, st.prevTypeBytes) {\n\t\t\t\tst.prevTypeBytes = append(st.prevTypeBytes[:0], st.typeBuf...)\n\t\t\t\tst.prevTypeStr = string(st.typeBuf)\n\t\t\t}\n\t\t\tst.selector = append(st.selector, st.prevTypeStr)\n\t\t\tif len(st.subTypeBuf) > 0 {\n\t\t\t\tif !bytes.Equal(st.subTypeBuf, st.prevSubTypeBytes) {\n\t\t\t\t\tst.prevSubTypeBytes = append(st.prevSubTypeBytes[:0], st.subTypeBuf...)\n\t\t\t\t\tst.prevSubTypeStr = string(st.subTypeBuf)\n\t\t\t\t}\n\t\t\t\tst.selector = append(st.selector, st.prevSubTypeStr)\n\t\t\t}\n\t\t}\n\n\t\tfor {\n\t\t\tkey, val, err := dec.NextField()\n\t\t\tif err != nil {\n\t\t\t\treturn err\n\t\t\t}\n\n\t\t\tif key == nil {\n\t\t\t\tbreak\n\t\t\t}\n\n\t\t\tif string(key) != \"value\" {\n\t\t\t\treturn fmt.Errorf(\"host %s: unknown field: '%s' (value: %#v)\", host, string(key), val)\n\t\t\t}\n\n\t\t\tif val.Kind() == lineprotocol.Float {\n\t\t\t\tmetric.Value = schema.Float(val.FloatV())\n\t\t\t} else if val.Kind() == lineprotocol.Int {\n\t\t\t\tmetric.Value = schema.Float(val.IntV())\n\t\t\t} else if val.Kind() == lineprotocol.Uint {\n\t\t\t\tmetric.Value = schema.Float(val.UintV())\n\t\t\t} else {\n\t\t\t\treturn fmt.Errorf(\"host %s: unsupported value type in message: %s\", host, val.Kind().String())\n\t\t\t}\n\t\t}\n\n\t\tif t, err = dec.Time(lineprotocol.Second, t); err != nil {\n\t\t\tt = time.Now()\n\t\t\tif t, err = dec.Time(lineprotocol.Millisecond, t); err != nil {\n\t\t\t\tt = time.Now()\n\t\t\t\tif t, err = dec.Time(lineprotocol.Microsecond, t); err != nil {\n\t\t\t\t\tt = time.Now()\n\t\t\t\t\tif t, err = dec.Time(lineprotocol.Nanosecond, t); err != nil {\n\t\t\t\t\t\treturn fmt.Errorf(\"host %s: timestamp : %#v with error : %#v\", host, t, err.Error())\n\t\t\t\t\t}\n\t\t\t\t}\n\t\t\t}\n\t\t}\n\n\t\tif err != nil {\n\t\t\treturn fmt.Errorf(\"host %s: timestamp : %#v with error : %#v\", host, t, err.Error())\n\t\t}\n\n\t\ttime := t.Unix()\n\n\t\tif Keys.Checkpoints.FileFormat == \"wal\" {\n\t\t\tWALMessages <- &WALMessage{\n\t\t\t\tMetricName: string(st.metricBuf),\n\t\t\t\tCluster: cluster,\n\t\t\t\tNode: host,\n\t\t\t\tSelector: append([]string{}, st.selector...),\n\t\t\t\tValue: metric.Value,\n\t\t\t\tTimestamp: time,\n\t\t\t}\n\t\t}\n\n\t\tif err := ms.WriteToLevel(lvl, st.selector, time, 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successfully."}]},"uuid":"3b8c8fe1-4401-48a1-b95e-c5a6deb6aeed","timestamp":"2026-03-18T05:09:19.967Z","toolUseResult":{"filePath":"/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/walCheckpoint.go","oldString":"var WALMessages = make(chan *WALMessage, 4096)","newString":"var WALMessages = make(chan *WALMessage, 65536)","originalFile":"// Copyright (C) NHR@FAU, University Erlangen-Nuremberg.\n// All rights reserved. This file is part of cc-backend.\n// Use of this source code is governed by a MIT-style\n// license that can be found in the LICENSE file.\n\n// Package metricstore provides walCheckpoint.go: WAL-based checkpoint implementation.\n//\n// This replaces the Avro shadow tree with an append-only Write-Ahead Log (WAL)\n// per host, eliminating the extra memory overhead of the AvroStore and providing\n// truly continuous (per-write) crash safety.\n//\n// # Architecture\n//\n//\tMetric write (DecodeLine)\n//\t │\n//\t ├─► WriteToLevel() → main MemoryStore (unchanged)\n//\t │\n//\t └─► WALMessages channel\n//\t │\n//\t ▼\n//\t WALStaging goroutine\n//\t │\n//\t ▼\n//\t checkpoints/cluster/host/current.wal (append-only, binary)\n//\n//\tPeriodic checkpoint (Checkpointing goroutine):\n//\t 1. Write .bin snapshot (column-oriented, from main tree)\n//\t 2. Signal WALStaging to truncate current.wal per host\n//\n//\tOn restart (FromCheckpoint):\n//\t 1. Load most recent .bin snapshot\n//\t 2. Replay current.wal (overwrite-safe: buffer.write handles duplicate timestamps)\n//\n// # WAL Record Format\n//\n//\t[4B magic 0xCC1DA7A1][4B payload_len][payload][4B CRC32]\n//\n//\tpayload:\n//\t [8B timestamp int64]\n//\t [2B metric_name_len uint16][N metric name bytes]\n//\t [1B selector_count uint8]\n//\t per selector: [1B selector_len uint8][M selector bytes]\n//\t [4B value float32 bits]\n//\n// # Binary Snapshot Format\n//\n//\t[4B magic 0xCC5B0001][8B from int64][8B to int64]\n//\tLevel tree (recursive):\n//\t [4B num_metrics uint32]\n//\t per metric:\n//\t [2B name_len uint16][N name bytes]\n//\t [8B frequency int64][8B start int64]\n//\t [4B num_values uint32][num_values × 4B float32]\n//\t [4B num_children uint32]\n//\t per child: [2B name_len uint16][N name bytes] + Level (recursive)\npackage metricstore\n\nimport (\n\t\"bufio\"\n\t\"context\"\n\t\"encoding/binary\"\n\t\"fmt\"\n\t\"hash/crc32\"\n\t\"io\"\n\t\"math\"\n\t\"os\"\n\t\"path\"\n\t\"strings\"\n\t\"sync\"\n\t\"sync/atomic\"\n\n\tcclog \"github.com/ClusterCockpit/cc-lib/v2/ccLogger\"\n\t\"github.com/ClusterCockpit/cc-lib/v2/schema\"\n)\n\n// Magic numbers for binary formats.\nconst (\n\twalFileMagic = uint32(0xCC1DA701) // WAL file header magic\n\twalRecordMagic = uint32(0xCC1DA7A1) // WAL record magic\n\tsnapFileMagic = uint32(0xCC5B0001) // Binary snapshot magic\n)\n\n// WALMessages is the channel for sending metric writes to the WAL staging goroutine.\n// Buffered to allow burst writes without blocking the metric ingestion path.\nvar WALMessages = make(chan *WALMessage, 4096)\n\n// walRotateCh is used by the checkpoint goroutine to request WAL file rotation\n// (close, delete, reopen) after a binary snapshot has been written.\nvar walRotateCh = make(chan walRotateReq, 256)\n\n// WALMessage represents a single metric write to be appended to the WAL.\n// Cluster and Node are NOT stored in the WAL record (inferred from file path).\ntype WALMessage struct {\n\tMetricName string\n\tCluster string\n\tNode string\n\tSelector []string\n\tValue schema.Float\n\tTimestamp int64\n}\n\n// walRotateReq requests WAL file rotation for a specific host directory.\n// The done channel is closed by the WAL goroutine when rotation is complete.\ntype walRotateReq struct {\n\thostDir string\n\tdone chan struct{}\n}\n\n// walFileState holds an open WAL file handle and buffered writer for one host directory.\ntype walFileState struct {\n\tf *os.File\n\tw *bufio.Writer\n}\n\n// WALStaging starts a background goroutine that receives WALMessage items\n// and appends binary WAL records to per-host current.wal files.\n// Also handles WAL rotation requests from the checkpoint goroutine.\nfunc WALStaging(wg *sync.WaitGroup, ctx context.Context) {\n\twg.Go(func() {\n\t\tif Keys.Checkpoints.FileFormat == \"json\" {\n\t\t\treturn\n\t\t}\n\n\t\thostFiles := make(map[string]*walFileState)\n\n\t\tdefer func() {\n\t\t\tfor _, ws := range hostFiles {\n\t\t\t\tif ws.f != nil {\n\t\t\t\t\tws.w.Flush()\n\t\t\t\t\tws.f.Close()\n\t\t\t\t}\n\t\t\t}\n\t\t}()\n\n\t\tgetOrOpenWAL := func(hostDir string) *walFileState {\n\t\t\tws, ok := hostFiles[hostDir]\n\t\t\tif ok {\n\t\t\t\treturn ws\n\t\t\t}\n\n\t\t\tif err := os.MkdirAll(hostDir, CheckpointDirPerms); err != nil {\n\t\t\t\tcclog.Errorf(\"[METRICSTORE]> WAL: mkdir %s: %v\", hostDir, err)\n\t\t\t\treturn nil\n\t\t\t}\n\n\t\t\twalPath := path.Join(hostDir, \"current.wal\")\n\t\t\tf, err := os.OpenFile(walPath, os.O_CREATE|os.O_APPEND|os.O_WRONLY, CheckpointFilePerms)\n\t\t\tif err != nil {\n\t\t\t\tcclog.Errorf(\"[METRICSTORE]> WAL: open %s: %v\", walPath, err)\n\t\t\t\treturn nil\n\t\t\t}\n\n\t\t\tw := bufio.NewWriter(f)\n\n\t\t\t// Write file header magic if file is new (empty).\n\t\t\tinfo, err := f.Stat()\n\t\t\tif err == nil && info.Size() == 0 {\n\t\t\t\tvar hdr [4]byte\n\t\t\t\tbinary.LittleEndian.PutUint32(hdr[:], walFileMagic)\n\t\t\t\tif _, err := w.Write(hdr[:]); err != nil {\n\t\t\t\t\tcclog.Errorf(\"[METRICSTORE]> WAL: write header %s: %v\", walPath, err)\n\t\t\t\t\tf.Close()\n\t\t\t\t\treturn nil\n\t\t\t\t}\n\t\t\t}\n\n\t\t\tws = &walFileState{f: f, w: w}\n\t\t\thostFiles[hostDir] = ws\n\t\t\treturn ws\n\t\t}\n\n\t\tprocessMsg := func(msg *WALMessage) {\n\t\t\thostDir := path.Join(Keys.Checkpoints.RootDir, msg.Cluster, msg.Node)\n\t\t\tws := getOrOpenWAL(hostDir)\n\t\t\tif ws == nil {\n\t\t\t\treturn\n\t\t\t}\n\t\t\tif err := writeWALRecord(ws.w, msg); err != nil {\n\t\t\t\tcclog.Errorf(\"[METRICSTORE]> WAL: write record: %v\", err)\n\t\t\t}\n\t\t}\n\n\t\tprocessRotate := func(req walRotateReq) {\n\t\t\tws, ok := hostFiles[req.hostDir]\n\t\t\tif ok && ws.f != nil {\n\t\t\t\tws.w.Flush()\n\t\t\t\tws.f.Close()\n\t\t\t\twalPath := path.Join(req.hostDir, \"current.wal\")\n\t\t\t\tif err := os.Remove(walPath); err != nil && !os.IsNotExist(err) {\n\t\t\t\t\tcclog.Errorf(\"[METRICSTORE]> WAL: remove %s: %v\", walPath, err)\n\t\t\t\t}\n\t\t\t\tdelete(hostFiles, req.hostDir)\n\t\t\t}\n\t\t\tclose(req.done)\n\t\t}\n\n\t\tdrain := func() {\n\t\t\tfor {\n\t\t\t\tselect {\n\t\t\t\tcase msg, ok := <-WALMessages:\n\t\t\t\t\tif !ok {\n\t\t\t\t\t\treturn\n\t\t\t\t\t}\n\t\t\t\t\tprocessMsg(msg)\n\t\t\t\tcase req := <-walRotateCh:\n\t\t\t\t\tprocessRotate(req)\n\t\t\t\tdefault:\n\t\t\t\t\t// Flush all buffered writers after draining remaining messages.\n\t\t\t\t\tfor _, ws := range hostFiles {\n\t\t\t\t\t\tif ws.f != nil {\n\t\t\t\t\t\t\tws.w.Flush()\n\t\t\t\t\t\t}\n\t\t\t\t\t}\n\t\t\t\t\treturn\n\t\t\t\t}\n\t\t\t}\n\t\t}\n\n\t\tfor {\n\t\t\tselect {\n\t\t\tcase <-ctx.Done():\n\t\t\t\tdrain()\n\t\t\t\treturn\n\t\t\tcase msg, ok := <-WALMessages:\n\t\t\t\tif !ok {\n\t\t\t\t\treturn\n\t\t\t\t}\n\t\t\t\tprocessMsg(msg)\n\t\t\tcase req := <-walRotateCh:\n\t\t\t\tprocessRotate(req)\n\t\t\t}\n\t\t}\n\t})\n}\n\n// RotateWALFiles sends rotation requests for the given host directories\n// and blocks until all rotations complete.\nfunc RotateWALFiles(hostDirs []string) {\n\tdones := make([]chan struct{}, len(hostDirs))\n\tfor i, dir := range hostDirs {\n\t\tdones[i] = make(chan struct{})\n\t\twalRotateCh <- walRotateReq{hostDir: dir, done: dones[i]}\n\t}\n\tfor _, done := range dones {\n\t\t<-done\n\t}\n}\n\n// RotateWALFiles sends rotation requests for the given host directories\n// and blocks until all rotations complete.\nfunc RotateWALFilesAfterShutdown(hostDirs []string) {\n\tfor _, dir := range hostDirs {\n\t\twalPath := path.Join(dir, \"current.wal\")\n\t\tif err := os.Remove(walPath); err != nil && !os.IsNotExist(err) {\n\t\t\tcclog.Errorf(\"[METRICSTORE]> WAL: remove %s: %v\", walPath, err)\n\t\t}\n\t}\n}\n\n// buildWALPayload encodes a WALMessage into a binary payload (without magic/length/CRC).\nfunc buildWALPayload(msg *WALMessage) []byte {\n\tsize := 8 + 2 + len(msg.MetricName) + 1 + 4\n\tfor _, s := range msg.Selector {\n\t\tsize += 1 + len(s)\n\t}\n\n\tbuf := make([]byte, 0, size)\n\n\t// Timestamp (8 bytes, little-endian int64)\n\tvar ts [8]byte\n\tbinary.LittleEndian.PutUint64(ts[:], uint64(msg.Timestamp))\n\tbuf = append(buf, ts[:]...)\n\n\t// Metric name (2-byte length prefix + bytes)\n\tvar mLen [2]byte\n\tbinary.LittleEndian.PutUint16(mLen[:], uint16(len(msg.MetricName)))\n\tbuf = append(buf, mLen[:]...)\n\tbuf = append(buf, msg.MetricName...)\n\n\t// Selector count (1 byte)\n\tbuf = append(buf, byte(len(msg.Selector)))\n\n\t// Selectors (1-byte length prefix + bytes each)\n\tfor _, sel := range msg.Selector {\n\t\tbuf = append(buf, byte(len(sel)))\n\t\tbuf = append(buf, sel...)\n\t}\n\n\t// Value (4 bytes, float32 bit representation)\n\tvar val [4]byte\n\tbinary.LittleEndian.PutUint32(val[:], math.Float32bits(float32(msg.Value)))\n\tbuf = append(buf, val[:]...)\n\n\treturn buf\n}\n\n// writeWALRecord appends a binary WAL record to the writer.\n// Format: [4B magic][4B payload_len][payload][4B CRC32]\nfunc writeWALRecord(w io.Writer, msg *WALMessage) error {\n\tpayload := buildWALPayload(msg)\n\tcrc := crc32.ChecksumIEEE(payload)\n\n\trecord := make([]byte, 0, 4+4+len(payload)+4)\n\n\tvar magic [4]byte\n\tbinary.LittleEndian.PutUint32(magic[:], walRecordMagic)\n\trecord = append(record, magic[:]...)\n\n\tvar pLen [4]byte\n\tbinary.LittleEndian.PutUint32(pLen[:], uint32(len(payload)))\n\trecord = append(record, pLen[:]...)\n\n\trecord = append(record, payload...)\n\n\tvar crcBytes [4]byte\n\tbinary.LittleEndian.PutUint32(crcBytes[:], crc)\n\trecord = append(record, crcBytes[:]...)\n\n\t_, err := w.Write(record)\n\treturn err\n}\n\n// readWALRecord reads one WAL record from the reader.\n// Returns (nil, nil) on clean EOF. Returns error on data corruption.\n// A CRC mismatch indicates a truncated trailing record (expected on crash).\nfunc readWALRecord(r io.Reader) (*WALMessage, error) {\n\tvar magic uint32\n\tif err := binary.Read(r, binary.LittleEndian, &magic); err != nil {\n\t\tif err == io.EOF {\n\t\t\treturn nil, nil // Clean EOF\n\t\t}\n\t\treturn nil, fmt.Errorf(\"read record magic: %w\", err)\n\t}\n\n\tif magic != walRecordMagic {\n\t\treturn nil, fmt.Errorf(\"invalid record magic 0x%08X (expected 0x%08X)\", magic, walRecordMagic)\n\t}\n\n\tvar payloadLen uint32\n\tif err := binary.Read(r, binary.LittleEndian, &payloadLen); err != nil {\n\t\treturn nil, fmt.Errorf(\"read payload length: %w\", err)\n\t}\n\n\tif payloadLen > 1<<20 { // 1 MB sanity limit\n\t\treturn nil, fmt.Errorf(\"record payload too large: %d bytes\", payloadLen)\n\t}\n\n\tpayload := make([]byte, payloadLen)\n\tif _, err := io.ReadFull(r, payload); err != nil {\n\t\treturn nil, fmt.Errorf(\"read payload: %w\", err)\n\t}\n\n\tvar storedCRC uint32\n\tif err := binary.Read(r, binary.LittleEndian, &storedCRC); err != nil {\n\t\treturn nil, fmt.Errorf(\"read CRC: %w\", err)\n\t}\n\n\tif crc32.ChecksumIEEE(payload) != storedCRC {\n\t\treturn nil, fmt.Errorf(\"CRC mismatch (truncated write or corruption)\")\n\t}\n\n\treturn parseWALPayload(payload)\n}\n\n// parseWALPayload decodes a binary payload into a WALMessage.\nfunc parseWALPayload(payload []byte) (*WALMessage, error) {\n\tif len(payload) < 8+2+1+4 {\n\t\treturn nil, fmt.Errorf(\"payload too short: %d bytes\", len(payload))\n\t}\n\n\toffset := 0\n\n\t// Timestamp (8 bytes)\n\tts := int64(binary.LittleEndian.Uint64(payload[offset : offset+8]))\n\toffset += 8\n\n\t// Metric name (2-byte length + bytes)\n\tif offset+2 > len(payload) {\n\t\treturn nil, fmt.Errorf(\"metric name length overflows payload\")\n\t}\n\tmLen := int(binary.LittleEndian.Uint16(payload[offset : offset+2]))\n\toffset += 2\n\n\tif offset+mLen > len(payload) {\n\t\treturn nil, fmt.Errorf(\"metric name overflows payload\")\n\t}\n\tmetricName := string(payload[offset : offset+mLen])\n\toffset += mLen\n\n\t// Selector count (1 byte)\n\tif offset >= len(payload) {\n\t\treturn nil, fmt.Errorf(\"selector count overflows payload\")\n\t}\n\tselCount := int(payload[offset])\n\toffset++\n\n\tselectors := make([]string, selCount)\n\tfor i := range selCount {\n\t\tif offset >= len(payload) {\n\t\t\treturn nil, fmt.Errorf(\"selector[%d] length overflows payload\", i)\n\t\t}\n\t\tsLen := int(payload[offset])\n\t\toffset++\n\n\t\tif offset+sLen > len(payload) {\n\t\t\treturn nil, fmt.Errorf(\"selector[%d] data overflows payload\", i)\n\t\t}\n\t\tselectors[i] = string(payload[offset : offset+sLen])\n\t\toffset += sLen\n\t}\n\n\t// Value (4 bytes, float32 bits)\n\tif offset+4 > len(payload) {\n\t\treturn nil, fmt.Errorf(\"value overflows payload\")\n\t}\n\tbits := binary.LittleEndian.Uint32(payload[offset : offset+4])\n\tvalue := schema.Float(math.Float32frombits(bits))\n\n\treturn &WALMessage{\n\t\tMetricName: metricName,\n\t\tTimestamp: ts,\n\t\tSelector: selectors,\n\t\tValue: value,\n\t}, nil\n}\n\n// loadWALFile reads a WAL file and replays all valid records into the Level tree.\n// l is the host-level node. Corrupt or partial trailing records are silently skipped\n// (expected on crash). Records older than 'from' are skipped.\nfunc (l *Level) loadWALFile(m *MemoryStore, f *os.File, from int64) error {\n\tbr := bufio.NewReader(f)\n\n\t// Verify file header magic.\n\tvar fileMagic uint32\n\tif err := binary.Read(br, binary.LittleEndian, &fileMagic); err != nil {\n\t\tif err == io.EOF {\n\t\t\treturn nil // Empty file, no data\n\t\t}\n\t\treturn fmt.Errorf(\"[METRICSTORE]> WAL: read file header: %w\", err)\n\t}\n\n\tif fileMagic != walFileMagic {\n\t\treturn fmt.Errorf(\"[METRICSTORE]> WAL: invalid file magic 0x%08X (expected 0x%08X)\", fileMagic, walFileMagic)\n\t}\n\n\t// Cache level lookups to avoid repeated tree traversal.\n\tlvlCache := make(map[string]*Level)\n\n\tfor {\n\t\tmsg, err := readWALRecord(br)\n\t\tif err != nil {\n\t\t\t// Truncated trailing record is expected after a crash; stop replaying.\n\t\t\tcclog.Debugf(\"[METRICSTORE]> WAL: stopping replay at corrupted/partial record: %v\", err)\n\t\t\tbreak\n\t\t}\n\t\tif msg == nil {\n\t\t\tbreak // Clean EOF\n\t\t}\n\n\t\tif msg.Timestamp < from {\n\t\t\tcontinue // Older than retention window\n\t\t}\n\n\t\tminfo, ok := m.Metrics[msg.MetricName]\n\t\tif !ok {\n\t\t\tcontinue // Unknown metric (config may have changed)\n\t\t}\n\n\t\t// Cache key is the null-separated selector path.\n\t\tcacheKey := joinSelector(msg.Selector)\n\t\tlvl, ok := lvlCache[cacheKey]\n\t\tif !ok {\n\t\t\tlvl = l.findLevelOrCreate(msg.Selector, len(m.Metrics))\n\t\t\tlvlCache[cacheKey] = lvl\n\t\t}\n\n\t\t// Write directly to the buffer, same as WriteToLevel but without the\n\t\t// global level lookup (we already have the right level).\n\t\tlvl.lock.Lock()\n\t\tb := lvl.metrics[minfo.offset]\n\t\tif b == nil {\n\t\t\tb = newBuffer(msg.Timestamp, minfo.Frequency)\n\t\t\tlvl.metrics[minfo.offset] = b\n\t\t}\n\t\tnb, writeErr := b.write(msg.Timestamp, msg.Value)\n\t\tif writeErr == nil && b != nb {\n\t\t\tlvl.metrics[minfo.offset] = nb\n\t\t}\n\t\t// Ignore write errors for timestamps before buffer start (can happen when\n\t\t// replaying WAL entries that predate a loaded snapshot's start time).\n\t\tlvl.lock.Unlock()\n\t}\n\n\treturn nil\n}\n\n// joinSelector builds a cache key from a selector slice using null bytes as separators.\nfunc joinSelector(sel []string) string {\n\tif len(sel) == 0 {\n\t\treturn \"\"\n\t}\n\tvar result strings.Builder\n\tresult.WriteString(sel[0])\n\tfor i := 1; i < len(sel); i++ {\n\t\tresult.WriteString(\"\\x00\" + sel[i])\n\t}\n\treturn result.String()\n}\n\n// ToCheckpointWAL writes binary snapshot files for all hosts in parallel.\n// Returns the number of files written, the list of host directories that were\n// successfully checkpointed (for WAL rotation), and any errors.\nfunc (m *MemoryStore) ToCheckpointWAL(dir string, from, to int64) (int, []string, error) {\n\t// Collect all cluster/host pairs.\n\tm.root.lock.RLock()\n\ttotalHosts := 0\n\tfor _, l1 := range m.root.children {\n\t\tl1.lock.RLock()\n\t\ttotalHosts += len(l1.children)\n\t\tl1.lock.RUnlock()\n\t}\n\tm.root.lock.RUnlock()\n\n\tlevels := make([]*Level, 0, totalHosts)\n\tselectors := make([][]string, 0, totalHosts)\n\n\tm.root.lock.RLock()\n\tfor sel1, l1 := range m.root.children {\n\t\tl1.lock.RLock()\n\t\tfor sel2, l2 := range l1.children {\n\t\t\tlevels = append(levels, l2)\n\t\t\tselectors = append(selectors, []string{sel1, sel2})\n\t\t}\n\t\tl1.lock.RUnlock()\n\t}\n\tm.root.lock.RUnlock()\n\n\ttype workItem struct {\n\t\tlevel *Level\n\t\thostDir string\n\t\tselector []string\n\t}\n\n\tn, errs := int32(0), int32(0)\n\tvar successDirs []string\n\tvar successMu sync.Mutex\n\n\tvar wg sync.WaitGroup\n\twg.Add(Keys.NumWorkers)\n\twork := make(chan workItem, Keys.NumWorkers*2)\n\n\tfor range Keys.NumWorkers {\n\t\tgo func() {\n\t\t\tdefer wg.Done()\n\t\t\tfor wi := range work {\n\t\t\t\terr := wi.level.toCheckpointBinary(wi.hostDir, from, to, m)\n\t\t\t\tif err != nil {\n\t\t\t\t\tif err == ErrNoNewArchiveData {\n\t\t\t\t\t\tcontinue\n\t\t\t\t\t}\n\t\t\t\t\tcclog.Errorf(\"[METRICSTORE]> binary checkpoint error for %s: %v\", wi.hostDir, err)\n\t\t\t\t\tatomic.AddInt32(&errs, 1)\n\t\t\t\t} else {\n\t\t\t\t\tatomic.AddInt32(&n, 1)\n\t\t\t\t\tsuccessMu.Lock()\n\t\t\t\t\tsuccessDirs = append(successDirs, wi.hostDir)\n\t\t\t\t\tsuccessMu.Unlock()\n\t\t\t\t}\n\t\t\t}\n\t\t}()\n\t}\n\n\tfor i := range levels {\n\t\thostDir := path.Join(dir, path.Join(selectors[i]...))\n\t\twork <- workItem{\n\t\t\tlevel: levels[i],\n\t\t\thostDir: hostDir,\n\t\t\tselector: selectors[i],\n\t\t}\n\t}\n\tclose(work)\n\twg.Wait()\n\n\tif errs > 0 {\n\t\treturn int(n), successDirs, fmt.Errorf(\"[METRICSTORE]> %d errors during binary checkpoint (%d successes)\", errs, n)\n\t}\n\treturn int(n), successDirs, nil\n}\n\n// toCheckpointBinary writes a binary snapshot file for a single host-level node.\n// Uses atomic rename (write to .tmp then rename) to avoid partial reads on crash.\nfunc (l *Level) toCheckpointBinary(dir string, from, to int64, m *MemoryStore) error {\n\tcf, err := l.toCheckpointFile(from, to, m)\n\tif err != nil {\n\t\treturn err\n\t}\n\tif cf == nil {\n\t\treturn ErrNoNewArchiveData\n\t}\n\n\tif err := os.MkdirAll(dir, CheckpointDirPerms); err != nil {\n\t\treturn fmt.Errorf(\"mkdir %s: %w\", dir, err)\n\t}\n\n\t// Write to a temp file first, then rename (atomic on POSIX).\n\ttmpPath := path.Join(dir, fmt.Sprintf(\"%d.bin.tmp\", from))\n\tfinalPath := path.Join(dir, fmt.Sprintf(\"%d.bin\", from))\n\n\tf, err := os.OpenFile(tmpPath, os.O_CREATE|os.O_WRONLY|os.O_TRUNC, CheckpointFilePerms)\n\tif err != nil {\n\t\treturn fmt.Errorf(\"open binary snapshot %s: %w\", tmpPath, err)\n\t}\n\n\tbw := bufio.NewWriter(f)\n\tif err := writeBinarySnapshotFile(bw, cf); err != nil {\n\t\tf.Close()\n\t\tos.Remove(tmpPath)\n\t\treturn fmt.Errorf(\"write binary snapshot: %w\", err)\n\t}\n\tif err := bw.Flush(); err != nil {\n\t\tf.Close()\n\t\tos.Remove(tmpPath)\n\t\treturn err\n\t}\n\tf.Close()\n\n\treturn os.Rename(tmpPath, finalPath)\n}\n\n// writeBinarySnapshotFile writes the binary snapshot file header and level tree.\nfunc writeBinarySnapshotFile(w io.Writer, cf *CheckpointFile) error {\n\tif err := binary.Write(w, binary.LittleEndian, snapFileMagic); err != nil {\n\t\treturn err\n\t}\n\tif err := binary.Write(w, binary.LittleEndian, cf.From); err != nil {\n\t\treturn err\n\t}\n\tif err := binary.Write(w, binary.LittleEndian, cf.To); err != nil {\n\t\treturn err\n\t}\n\treturn writeBinaryLevel(w, cf)\n}\n\n// writeBinaryLevel recursively writes a CheckpointFile level in binary format.\nfunc writeBinaryLevel(w io.Writer, cf *CheckpointFile) error {\n\tif err := binary.Write(w, binary.LittleEndian, uint32(len(cf.Metrics))); err != nil {\n\t\treturn err\n\t}\n\n\tfor name, metric := range cf.Metrics {\n\t\tif err := writeString16(w, name); err != nil {\n\t\t\treturn err\n\t\t}\n\t\tif err := binary.Write(w, binary.LittleEndian, metric.Frequency); err != nil {\n\t\t\treturn err\n\t\t}\n\t\tif err := binary.Write(w, binary.LittleEndian, metric.Start); err != nil {\n\t\t\treturn err\n\t\t}\n\t\tif err := binary.Write(w, binary.LittleEndian, uint32(len(metric.Data))); err != nil {\n\t\t\treturn err\n\t\t}\n\t\tfor _, v := range metric.Data {\n\t\t\tif err := binary.Write(w, binary.LittleEndian, math.Float32bits(float32(v))); err != nil {\n\t\t\t\treturn err\n\t\t\t}\n\t\t}\n\t}\n\n\tif err := binary.Write(w, binary.LittleEndian, uint32(len(cf.Children))); err != nil {\n\t\treturn err\n\t}\n\n\tfor name, child := range cf.Children {\n\t\tif err := writeString16(w, name); err != nil {\n\t\t\treturn err\n\t\t}\n\t\tif err := writeBinaryLevel(w, child); err != nil {\n\t\t\treturn err\n\t\t}\n\t}\n\n\treturn nil\n}\n\n// writeString16 writes a 2-byte length-prefixed string to w.\nfunc writeString16(w io.Writer, s string) error {\n\tif err := binary.Write(w, binary.LittleEndian, uint16(len(s))); err != nil {\n\t\treturn err\n\t}\n\t_, err := io.WriteString(w, s)\n\treturn err\n}\n\n// loadBinaryFile reads a binary snapshot file and loads data into the Level tree.\n// The retention check (from) is applied to the file's 'to' timestamp.\nfunc (l *Level) loadBinaryFile(m *MemoryStore, f *os.File, from int64) error {\n\tbr := bufio.NewReader(f)\n\n\tvar magic uint32\n\tif err := binary.Read(br, binary.LittleEndian, &magic); err != nil {\n\t\treturn fmt.Errorf(\"[METRICSTORE]> binary snapshot: read magic: %w\", err)\n\t}\n\tif magic != snapFileMagic {\n\t\treturn fmt.Errorf(\"[METRICSTORE]> binary snapshot: invalid magic 0x%08X (expected 0x%08X)\", magic, snapFileMagic)\n\t}\n\n\tvar fileFrom, fileTo int64\n\tif err := binary.Read(br, binary.LittleEndian, &fileFrom); err != nil {\n\t\treturn fmt.Errorf(\"[METRICSTORE]> binary snapshot: read from: %w\", err)\n\t}\n\tif err := binary.Read(br, binary.LittleEndian, &fileTo); err != nil {\n\t\treturn fmt.Errorf(\"[METRICSTORE]> binary snapshot: read to: %w\", err)\n\t}\n\n\tif fileTo != 0 && fileTo < from {\n\t\treturn nil // File is older than retention window, skip it\n\t}\n\n\tcf, err := readBinaryLevel(br)\n\tif err != nil {\n\t\treturn fmt.Errorf(\"[METRICSTORE]> binary snapshot: read level tree: %w\", err)\n\t}\n\tcf.From = fileFrom\n\tcf.To = fileTo\n\n\treturn l.loadFile(cf, m)\n}\n\n// readBinaryLevel recursively reads a level from the binary snapshot format.\nfunc readBinaryLevel(r io.Reader) (*CheckpointFile, error) {\n\tcf := &CheckpointFile{\n\t\tMetrics: make(map[string]*CheckpointMetrics),\n\t\tChildren: make(map[string]*CheckpointFile),\n\t}\n\n\tvar numMetrics uint32\n\tif err := binary.Read(r, binary.LittleEndian, &numMetrics); err != nil {\n\t\treturn nil, fmt.Errorf(\"read num_metrics: %w\", err)\n\t}\n\n\tfor range numMetrics {\n\t\tname, err := readString16(r)\n\t\tif err != nil {\n\t\t\treturn nil, fmt.Errorf(\"read metric name: %w\", err)\n\t\t}\n\n\t\tvar freq, start int64\n\t\tif err := binary.Read(r, binary.LittleEndian, &freq); err != nil {\n\t\t\treturn nil, fmt.Errorf(\"read frequency for %s: %w\", name, err)\n\t\t}\n\t\tif err := binary.Read(r, binary.LittleEndian, &start); err != nil {\n\t\t\treturn nil, fmt.Errorf(\"read start for %s: %w\", name, err)\n\t\t}\n\n\t\tvar numValues uint32\n\t\tif err := binary.Read(r, binary.LittleEndian, &numValues); err != nil {\n\t\t\treturn nil, fmt.Errorf(\"read num_values for %s: %w\", name, err)\n\t\t}\n\n\t\tdata := make([]schema.Float, numValues)\n\t\tfor i := range numValues {\n\t\t\tvar bits uint32\n\t\t\tif err := binary.Read(r, binary.LittleEndian, &bits); err != nil {\n\t\t\t\treturn nil, fmt.Errorf(\"read value[%d] for %s: %w\", i, name, err)\n\t\t\t}\n\t\t\tdata[i] = schema.Float(math.Float32frombits(bits))\n\t\t}\n\n\t\tcf.Metrics[name] = &CheckpointMetrics{\n\t\t\tFrequency: freq,\n\t\t\tStart: start,\n\t\t\tData: data,\n\t\t}\n\t}\n\n\tvar numChildren uint32\n\tif err := binary.Read(r, binary.LittleEndian, &numChildren); err != nil {\n\t\treturn nil, fmt.Errorf(\"read num_children: %w\", err)\n\t}\n\n\tfor range numChildren {\n\t\tchildName, err := readString16(r)\n\t\tif err != nil {\n\t\t\treturn nil, fmt.Errorf(\"read child name: %w\", err)\n\t\t}\n\n\t\tchild, err := readBinaryLevel(r)\n\t\tif err != nil {\n\t\t\treturn nil, fmt.Errorf(\"read child %s: %w\", childName, err)\n\t\t}\n\t\tcf.Children[childName] = child\n\t}\n\n\treturn cf, nil\n}\n\n// readString16 reads a 2-byte length-prefixed string from r.\nfunc readString16(r io.Reader) (string, error) {\n\tvar sLen uint16\n\tif err := binary.Read(r, binary.LittleEndian, &sLen); err != nil {\n\t\treturn \"\", err\n\t}\n\tbuf := make([]byte, sLen)\n\tif _, err := io.ReadFull(r, buf); err != nil {\n\t\treturn \"\", err\n\t}\n\treturn string(buf), nil\n}\n","structuredPatch":[{"oldStart":82,"oldLines":7,"newStart":82,"newLines":7,"lines":[" "," // WALMessages is the channel for sending metric writes to the WAL staging goroutine."," // Buffered to allow burst writes without blocking the metric ingestion path.","-var WALMessages = make(chan *WALMessage, 4096)","+var WALMessages = make(chan *WALMessage, 65536)"," "," // walRotateCh is used by the checkpoint goroutine to request WAL file rotation"," // (close, delete, reopen) after a binary snapshot has been written."]}],"userModified":false,"replaceAll":false},"sourceToolAssistantUUID":"0e36fdaf-16c7-4e4d-8e3e-91e98e360c47","userType":"external","entrypoint":"cli","cwd":"/Users/jan/prg/ClusterCockpit/cc-backend","sessionId":"5eb20a94-f8df-4979-a0ae-2aa99bfad884","version":"2.1.78","gitBranch":"hotfix","slug":"bright-wandering-flurry"} +{"parentUuid":"3b8c8fe1-4401-48a1-b95e-c5a6deb6aeed","isSidechain":false,"message":{"model":"claude-opus-4-6","id":"msg_01AobXru3uSFMpAoybRxFtPy","type":"message","role":"assistant","content":[{"type":"text","text":"**Change 3:** Non-blocking WAL send with overflow logging."}],"stop_reason":null,"stop_sequence":null,"usage":{"input_tokens":1,"cache_creation_input_tokens":228,"cache_read_input_tokens":51117,"cache_creation":{"ephemeral_5m_input_tokens":0,"ephemeral_1h_input_tokens":228},"output_tokens":1,"service_tier":"standard","inference_geo":"not_available"}},"requestId":"req_011CZ9y7sydCiPNtGNNYhrJi","type":"assistant","uuid":"0032dbea-9b05-43e1-b407-638a3c753abe","timestamp":"2026-03-18T05:09:23.819Z","userType":"external","entrypoint":"cli","cwd":"/Users/jan/prg/ClusterCockpit/cc-backend","sessionId":"5eb20a94-f8df-4979-a0ae-2aa99bfad884","version":"2.1.78","gitBranch":"hotfix","slug":"bright-wandering-flurry"} 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\"github.com/ClusterCockpit/cc-lib/v2/ccLogger\"\n\t\"github.com/ClusterCockpit/cc-lib/v2/nats\"\n\t\"github.com/ClusterCockpit/cc-lib/v2/schema\"\n\t\"github.com/ClusterCockpit/cc-line-protocol/v2/lineprotocol\""},"caller":{"type":"direct"}}],"stop_reason":"tool_use","stop_sequence":null,"usage":{"input_tokens":1,"cache_creation_input_tokens":228,"cache_read_input_tokens":51117,"output_tokens":402,"server_tool_use":{"web_search_requests":0,"web_fetch_requests":0},"service_tier":"standard","cache_creation":{"ephemeral_1h_input_tokens":228,"ephemeral_5m_input_tokens":0},"inference_geo":"","iterations":[],"speed":"standard"}},"requestId":"req_011CZ9y7sydCiPNtGNNYhrJi","type":"assistant","uuid":"126fb8cc-b920-4d0f-b9e3-9cdfec264905","timestamp":"2026-03-18T05:09:26.419Z","userType":"external","entrypoint":"cli","cwd":"/Users/jan/prg/ClusterCockpit/cc-backend","sessionId":"5eb20a94-f8df-4979-a0ae-2aa99bfad884","version":"2.1.78","gitBranch":"hotfix","slug":"bright-wandering-flurry"} 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successfully."}]},"uuid":"665d25f9-6347-421e-a95d-148ffc26547b","timestamp":"2026-03-18T05:09:26.426Z","toolUseResult":{"filePath":"/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/lineprotocol.go","oldString":"\t\"bytes\"\n\t\"context\"\n\t\"fmt\"\n\t\"sync\"\n\t\"time\"\n\n\tcclog \"github.com/ClusterCockpit/cc-lib/v2/ccLogger\"\n\t\"github.com/ClusterCockpit/cc-lib/v2/nats\"\n\t\"github.com/ClusterCockpit/cc-lib/v2/schema\"\n\t\"github.com/ClusterCockpit/cc-line-protocol/v2/lineprotocol\"","newString":"\t\"bytes\"\n\t\"context\"\n\t\"fmt\"\n\t\"sync\"\n\t\"sync/atomic\"\n\t\"time\"\n\n\tcclog \"github.com/ClusterCockpit/cc-lib/v2/ccLogger\"\n\t\"github.com/ClusterCockpit/cc-lib/v2/nats\"\n\t\"github.com/ClusterCockpit/cc-lib/v2/schema\"\n\t\"github.com/ClusterCockpit/cc-line-protocol/v2/lineprotocol\"","originalFile":"// Copyright (C) NHR@FAU, University Erlangen-Nuremberg.\n// All rights reserved. This file is part of cc-backend.\n// Use of this source code is governed by a MIT-style\n// license that can be found in the LICENSE file.\n\n// This file implements ingestion of InfluxDB line-protocol metric data received\n// over NATS. Each line encodes one metric sample with the following structure:\n//\n//\t[,cluster=][,hostname=][,type=][,type-id=][,subtype=][,stype-id=] value= []\n//\n// The measurement name identifies the metric (e.g. \"cpu_load\"). Tags provide\n// routing information (cluster, host) and optional sub-device selectors (type,\n// subtype). Only one field is expected per line: \"value\".\n//\n// After decoding, each sample is:\n// 1. Written to the in-memory store via ms.WriteToLevel.\n// 2. If the checkpoint format is \"wal\", also forwarded to the WAL staging\n// goroutine via the WALMessages channel for durable write-ahead logging.\npackage metricstore\n\nimport (\n\t\"bytes\"\n\t\"context\"\n\t\"fmt\"\n\t\"sync\"\n\t\"time\"\n\n\tcclog \"github.com/ClusterCockpit/cc-lib/v2/ccLogger\"\n\t\"github.com/ClusterCockpit/cc-lib/v2/nats\"\n\t\"github.com/ClusterCockpit/cc-lib/v2/schema\"\n\t\"github.com/ClusterCockpit/cc-line-protocol/v2/lineprotocol\"\n)\n\n// ReceiveNats subscribes to all configured NATS subjects and feeds incoming\n// line-protocol messages into the MemoryStore.\n//\n// When workers > 1 a pool of goroutines drains a shared channel so that\n// multiple messages can be decoded in parallel. With workers == 1 the NATS\n// callback decodes inline (no channel overhead, lower latency).\n//\n// The function blocks until ctx is cancelled and all worker goroutines have\n// finished. It returns nil when the NATS client is not configured; callers\n// should treat that as a no-op rather than an error.\nfunc ReceiveNats(ms *MemoryStore,\n\tworkers int,\n\tctx context.Context,\n) error {\n\tnc := nats.GetClient()\n\n\tif nc == nil {\n\t\tcclog.Warn(\"NATS client not initialized\")\n\t\treturn nil\n\t}\n\n\tvar wg sync.WaitGroup\n\tmsgs := make(chan []byte, max(workers*256, 8192))\n\n\tfor _, sc := range *Keys.Subscriptions {\n\t\tclusterTag := sc.ClusterTag\n\t\tif workers > 1 {\n\t\t\twg.Add(workers)\n\n\t\t\tfor range workers {\n\t\t\t\tgo func() {\n\t\t\t\t\tdefer wg.Done()\n\t\t\t\t\tfor m := range msgs {\n\t\t\t\t\t\tdec := lineprotocol.NewDecoderWithBytes(m)\n\t\t\t\t\t\tif err := DecodeLine(dec, ms, clusterTag); err != nil {\n\t\t\t\t\t\t\tcclog.Errorf(\"error: %s\", err.Error())\n\t\t\t\t\t\t}\n\t\t\t\t\t}\n\t\t\t\t}()\n\t\t\t}\n\n\t\t\tnc.Subscribe(sc.SubscribeTo, func(subject string, data []byte) {\n\t\t\t\tselect {\n\t\t\t\tcase msgs <- data:\n\t\t\t\tcase <-ctx.Done():\n\t\t\t\t}\n\t\t\t})\n\t\t} else {\n\t\t\tnc.Subscribe(sc.SubscribeTo, func(subject string, data []byte) {\n\t\t\t\tdec := lineprotocol.NewDecoderWithBytes(data)\n\t\t\t\tif err := DecodeLine(dec, ms, clusterTag); err != nil {\n\t\t\t\t\tcclog.Errorf(\"error: %s\", err.Error())\n\t\t\t\t}\n\t\t\t})\n\t\t}\n\t\tcclog.Infof(\"NATS subscription to '%s' established\", sc.SubscribeTo)\n\t}\n\n\tgo func() {\n\t\t<-ctx.Done()\n\t\tclose(msgs)\n\t}()\n\n\twg.Wait()\n\n\treturn nil\n}\n\n// reorder prepends prefix to buf in-place when buf has enough spare capacity,\n// avoiding an allocation. Falls back to a regular append otherwise.\n//\n// It is used to assemble the \"type\" and \"subtype\" selector\n// strings when the type tag arrives before the type-id tag in the line, so the\n// two byte slices need to be concatenated in tag-declaration order regardless\n// of wire order.\nfunc reorder(buf, prefix []byte) []byte {\n\tn := len(prefix)\n\tm := len(buf)\n\tif cap(buf) < m+n {\n\t\treturn append(prefix[:n:n], buf...)\n\t} else {\n\t\tbuf = buf[:n+m]\n\t\tfor i := m - 1; i >= 0; i-- {\n\t\t\tbuf[i+n] = buf[i]\n\t\t}\n\t\tfor i := range n {\n\t\t\tbuf[i] = prefix[i]\n\t\t}\n\t\treturn buf\n\t}\n}\n\n// decodeState holds the per-call scratch buffers used by DecodeLine.\n// Instances are recycled via decodeStatePool to avoid repeated allocations\n// during high-throughput ingestion.\ntype decodeState struct {\n\t// metricBuf holds a copy of the current measurement name (line-protocol\n\t// measurement field). Copied because dec.Measurement() returns a slice\n\t// that is invalidated by the next decoder call.\n\tmetricBuf []byte\n\n\t// selector is the sub-device path passed to WriteToLevel and WALMessage\n\t// (e.g. [\"socket0\"] or [\"socket0\", \"memctrl1\"]). Reused across lines.\n\tselector []string\n\n\t// typeBuf accumulates the concatenated \"type\"+\"type-id\" tag value for the\n\t// current line. Reset at the start of each line's tag-decode loop.\n\ttypeBuf []byte\n\n\t// subTypeBuf accumulates the concatenated \"subtype\"+\"stype-id\" tag value.\n\t// Reset at the start of each line's tag-decode loop.\n\tsubTypeBuf []byte\n\n\t// prevTypeBytes / prevTypeStr cache the last seen typeBuf content and its\n\t// string conversion. Because consecutive lines in a batch typically address\n\t// the same sub-device, the cache hit rate is very high and avoids\n\t// repeated []byte→string allocations.\n\tprevTypeBytes []byte\n\tprevTypeStr string\n\n\t// prevSubTypeBytes / prevSubTypeStr are the same cache for the subtype.\n\tprevSubTypeBytes []byte\n\tprevSubTypeStr string\n}\n\n// decodeStatePool recycles decodeState values across DecodeLine calls to\n// reduce GC pressure during sustained metric ingestion.\nvar decodeStatePool = sync.Pool{\n\tNew: func() any {\n\t\treturn &decodeState{\n\t\t\tmetricBuf: make([]byte, 0, 16),\n\t\t\tselector: make([]string, 0, 4),\n\t\t\ttypeBuf: make([]byte, 0, 16),\n\t\t\tsubTypeBuf: make([]byte, 0, 16),\n\t\t}\n\t},\n}\n\n// DecodeLine reads all lines from dec (InfluxDB line-protocol) and writes each\n// decoded metric sample into ms.\n//\n// clusterDefault is used as the cluster name for lines that do not carry a\n// \"cluster\" tag. Callers typically supply the ClusterTag value from the NATS\n// subscription configuration.\n//\n// Performance notes:\n// - A decodeState is obtained from decodeStatePool to reuse scratch buffers.\n// - The Level pointer (host-level node in the metric tree) is cached across\n// consecutive lines that share the same cluster+host pair to avoid\n// repeated lock acquisitions on the root and cluster levels.\n// - []byte→string conversions for type/subtype selectors are cached via\n// prevType*/prevSubType* fields because batches typically repeat the same\n// sub-device identifiers.\n// - Timestamp parsing tries Second precision first; if that fails it retries\n// Millisecond, Microsecond, and Nanosecond in turn. A missing timestamp\n// falls back to time.Now().\n//\n// When the checkpoint format is \"wal\" each successfully decoded sample is also\n// sent to WALMessages so the WAL staging goroutine can persist it durably\n// before the next binary snapshot.\nfunc DecodeLine(dec *lineprotocol.Decoder,\n\tms *MemoryStore,\n\tclusterDefault string,\n) error {\n\t// Reduce allocations in loop:\n\tt := time.Now()\n\tmetric := Metric{}\n\tst := decodeStatePool.Get().(*decodeState)\n\tdefer decodeStatePool.Put(st)\n\n\t// Optimize for the case where all lines in a \"batch\" are about the same\n\t// cluster and host. By using `WriteToLevel` (level = host), we do not need\n\t// to take the root- and cluster-level lock as often.\n\tvar lvl *Level = nil\n\tprevCluster, prevHost := \"\", \"\"\n\n\tvar ok bool\n\tfor dec.Next() {\n\t\trawmeasurement, err := dec.Measurement()\n\t\tif err != nil {\n\t\t\treturn err\n\t\t}\n\n\t\t// Needs to be copied because another call to dec.* would\n\t\t// invalidate the returned slice.\n\t\tst.metricBuf = append(st.metricBuf[:0], rawmeasurement...)\n\n\t\t// The go compiler optimizes map[string(byteslice)] lookups:\n\t\tmetric.MetricConfig, ok = ms.Metrics[string(rawmeasurement)]\n\t\tif !ok {\n\t\t\tcontinue\n\t\t}\n\n\t\tst.typeBuf, st.subTypeBuf = st.typeBuf[:0], st.subTypeBuf[:0]\n\t\tcluster, host := clusterDefault, \"\"\n\t\tfor {\n\t\t\tkey, val, err := dec.NextTag()\n\t\t\tif err != nil {\n\t\t\t\treturn err\n\t\t\t}\n\t\t\tif key == nil {\n\t\t\t\tbreak\n\t\t\t}\n\n\t\t\t// The go compiler optimizes string([]byte{...}) == \"...\":\n\t\t\tswitch string(key) {\n\t\t\tcase \"cluster\":\n\t\t\t\tif string(val) == prevCluster {\n\t\t\t\t\tcluster = prevCluster\n\t\t\t\t} else {\n\t\t\t\t\tcluster = string(val)\n\t\t\t\t\tlvl = nil\n\t\t\t\t}\n\t\t\tcase \"hostname\", \"host\":\n\t\t\t\tif string(val) == prevHost {\n\t\t\t\t\thost = prevHost\n\t\t\t\t} else {\n\t\t\t\t\thost = string(val)\n\t\t\t\t\tlvl = nil\n\t\t\t\t}\n\t\t\tcase \"type\":\n\t\t\t\tif string(val) == \"node\" {\n\t\t\t\t\tbreak\n\t\t\t\t}\n\n\t\t\t\t// We cannot be sure that the \"type\" tag comes before the \"type-id\" tag:\n\t\t\t\tif len(st.typeBuf) == 0 {\n\t\t\t\t\tst.typeBuf = append(st.typeBuf, val...)\n\t\t\t\t} else {\n\t\t\t\t\tst.typeBuf = reorder(st.typeBuf, val)\n\t\t\t\t}\n\t\t\tcase \"type-id\":\n\t\t\t\tst.typeBuf = append(st.typeBuf, val...)\n\t\t\tcase \"subtype\":\n\t\t\t\t// We cannot be sure that the \"subtype\" tag comes before the \"stype-id\" tag:\n\t\t\t\tif len(st.subTypeBuf) == 0 {\n\t\t\t\t\tst.subTypeBuf = append(st.subTypeBuf, val...)\n\t\t\t\t} else {\n\t\t\t\t\tst.subTypeBuf = reorder(st.subTypeBuf, val)\n\t\t\t\t}\n\t\t\tcase \"stype-id\":\n\t\t\t\tst.subTypeBuf = append(st.subTypeBuf, val...)\n\t\t\tdefault:\n\t\t\t}\n\t\t}\n\n\t\t// If the cluster or host changed, the lvl was set to nil\n\t\tif lvl == nil {\n\t\t\tst.selector = st.selector[:2]\n\t\t\tst.selector[0], st.selector[1] = cluster, host\n\t\t\tlvl = ms.GetLevel(st.selector)\n\t\t\tprevCluster, prevHost = cluster, host\n\t\t}\n\n\t\t// subtypes: cache []byte→string conversions; messages in a batch typically\n\t\t// share the same type/subtype so the hit rate is very high.\n\t\tst.selector = st.selector[:0]\n\t\tif len(st.typeBuf) > 0 {\n\t\t\tif !bytes.Equal(st.typeBuf, st.prevTypeBytes) {\n\t\t\t\tst.prevTypeBytes = append(st.prevTypeBytes[:0], st.typeBuf...)\n\t\t\t\tst.prevTypeStr = string(st.typeBuf)\n\t\t\t}\n\t\t\tst.selector = append(st.selector, st.prevTypeStr)\n\t\t\tif len(st.subTypeBuf) > 0 {\n\t\t\t\tif !bytes.Equal(st.subTypeBuf, st.prevSubTypeBytes) {\n\t\t\t\t\tst.prevSubTypeBytes = append(st.prevSubTypeBytes[:0], st.subTypeBuf...)\n\t\t\t\t\tst.prevSubTypeStr = string(st.subTypeBuf)\n\t\t\t\t}\n\t\t\t\tst.selector = append(st.selector, st.prevSubTypeStr)\n\t\t\t}\n\t\t}\n\n\t\tfor {\n\t\t\tkey, val, err := dec.NextField()\n\t\t\tif err != nil {\n\t\t\t\treturn err\n\t\t\t}\n\n\t\t\tif key == nil {\n\t\t\t\tbreak\n\t\t\t}\n\n\t\t\tif string(key) != \"value\" {\n\t\t\t\treturn fmt.Errorf(\"host %s: unknown field: '%s' (value: %#v)\", host, string(key), val)\n\t\t\t}\n\n\t\t\tif val.Kind() == lineprotocol.Float {\n\t\t\t\tmetric.Value = schema.Float(val.FloatV())\n\t\t\t} else if val.Kind() == lineprotocol.Int {\n\t\t\t\tmetric.Value = schema.Float(val.IntV())\n\t\t\t} else if val.Kind() == lineprotocol.Uint {\n\t\t\t\tmetric.Value = schema.Float(val.UintV())\n\t\t\t} else {\n\t\t\t\treturn fmt.Errorf(\"host %s: unsupported value type in message: %s\", host, val.Kind().String())\n\t\t\t}\n\t\t}\n\n\t\tif t, err = dec.Time(lineprotocol.Second, t); err != nil {\n\t\t\tt = time.Now()\n\t\t\tif t, err = dec.Time(lineprotocol.Millisecond, t); err != nil {\n\t\t\t\tt = time.Now()\n\t\t\t\tif t, err = dec.Time(lineprotocol.Microsecond, t); err != nil {\n\t\t\t\t\tt = time.Now()\n\t\t\t\t\tif t, err = dec.Time(lineprotocol.Nanosecond, t); err != nil {\n\t\t\t\t\t\treturn fmt.Errorf(\"host %s: timestamp : %#v with error : %#v\", host, t, err.Error())\n\t\t\t\t\t}\n\t\t\t\t}\n\t\t\t}\n\t\t}\n\n\t\tif err != nil {\n\t\t\treturn fmt.Errorf(\"host %s: timestamp : %#v with error : %#v\", host, t, err.Error())\n\t\t}\n\n\t\ttime := t.Unix()\n\n\t\tif Keys.Checkpoints.FileFormat == \"wal\" {\n\t\t\tWALMessages <- &WALMessage{\n\t\t\t\tMetricName: string(st.metricBuf),\n\t\t\t\tCluster: cluster,\n\t\t\t\tNode: host,\n\t\t\t\tSelector: append([]string{}, st.selector...),\n\t\t\t\tValue: metric.Value,\n\t\t\t\tTimestamp: time,\n\t\t\t}\n\t\t}\n\n\t\tif err := ms.WriteToLevel(lvl, st.selector, time, []Metric{metric}); err != nil {\n\t\t\tcclog.Warnf(\"write error for host %s metric %s at ts %d: %s\", host, string(st.metricBuf), time, err.Error())\n\t\t\tcontinue\n\t\t}\n\t}\n\treturn nil\n}\n","structuredPatch":[{"oldStart":23,"oldLines":6,"newStart":23,"newLines":7,"lines":[" \"context\""," \"fmt\""," \"sync\"","+ \"sync/atomic\""," \"time\""," "," cclog \"github.com/ClusterCockpit/cc-lib/v2/ccLogger\""]}],"userModified":false,"replaceAll":false},"sourceToolAssistantUUID":"126fb8cc-b920-4d0f-b9e3-9cdfec264905","userType":"external","entrypoint":"cli","cwd":"/Users/jan/prg/ClusterCockpit/cc-backend","sessionId":"5eb20a94-f8df-4979-a0ae-2aa99bfad884","version":"2.1.78","gitBranch":"hotfix","slug":"bright-wandering-flurry"} +{"parentUuid":"665d25f9-6347-421e-a95d-148ffc26547b","isSidechain":false,"message":{"model":"claude-opus-4-6","id":"msg_015g8NTxn5Cgz2JVtjS9UwmA","type":"message","role":"assistant","content":[{"type":"text","text":"Now add the dropped counter and replace the blocking WAL send:"}],"stop_reason":null,"stop_sequence":null,"usage":{"input_tokens":1,"cache_creation_input_tokens":450,"cache_read_input_tokens":51345,"cache_creation":{"ephemeral_5m_input_tokens":0,"ephemeral_1h_input_tokens":450},"output_tokens":1,"service_tier":"standard","inference_geo":"not_available"}},"requestId":"req_011CZ9y8Mcn5LTjo1VvKAQbc","type":"assistant","uuid":"6bee413c-8c87-4626-aa79-9acbca83c07a","timestamp":"2026-03-18T05:09:31.696Z","userType":"external","entrypoint":"cli","cwd":"/Users/jan/prg/ClusterCockpit/cc-backend","sessionId":"5eb20a94-f8df-4979-a0ae-2aa99bfad884","version":"2.1.78","gitBranch":"hotfix","slug":"bright-wandering-flurry"} +{"parentUuid":"6bee413c-8c87-4626-aa79-9acbca83c07a","isSidechain":false,"message":{"model":"claude-opus-4-6","id":"msg_015g8NTxn5Cgz2JVtjS9UwmA","type":"message","role":"assistant","content":[{"type":"tool_use","id":"toolu_016fpskgo3MTpnW9FjWJkfxV","name":"Edit","input":{"replace_all":false,"file_path":"/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/lineprotocol.go","old_string":"// decodeState holds the per-call scratch buffers used by DecodeLine.","new_string":"// walDropped counts WAL messages dropped due to a full channel.\n// Logged periodically; not critical since binary snapshots capture the data.\nvar walDropped atomic.Int64\n\n// decodeState holds the per-call scratch buffers used by DecodeLine."},"caller":{"type":"direct"}}],"stop_reason":"tool_use","stop_sequence":null,"usage":{"input_tokens":1,"cache_creation_input_tokens":450,"cache_read_input_tokens":51345,"output_tokens":227,"server_tool_use":{"web_search_requests":0,"web_fetch_requests":0},"service_tier":"standard","cache_creation":{"ephemeral_1h_input_tokens":450,"ephemeral_5m_input_tokens":0},"inference_geo":"","iterations":[],"speed":"standard"}},"requestId":"req_011CZ9y8Mcn5LTjo1VvKAQbc","type":"assistant","uuid":"a144f71e-4dce-4572-bed1-be30504a4e1b","timestamp":"2026-03-18T05:09:33.997Z","userType":"external","entrypoint":"cli","cwd":"/Users/jan/prg/ClusterCockpit/cc-backend","sessionId":"5eb20a94-f8df-4979-a0ae-2aa99bfad884","version":"2.1.78","gitBranch":"hotfix","slug":"bright-wandering-flurry"} +{"parentUuid":"a144f71e-4dce-4572-bed1-be30504a4e1b","isSidechain":false,"type":"progress","data":{"type":"hook_progress","hookEvent":"PostToolUse","hookName":"PostToolUse:Edit","command":"callback"},"parentToolUseID":"toolu_016fpskgo3MTpnW9FjWJkfxV","toolUseID":"toolu_016fpskgo3MTpnW9FjWJkfxV","timestamp":"2026-03-18T05:09:34.021Z","uuid":"acea17ca-bec9-423e-a7ce-16148137252c","userType":"external","entrypoint":"cli","cwd":"/Users/jan/prg/ClusterCockpit/cc-backend","sessionId":"5eb20a94-f8df-4979-a0ae-2aa99bfad884","version":"2.1.78","gitBranch":"hotfix","slug":"bright-wandering-flurry"} +{"parentUuid":"a144f71e-4dce-4572-bed1-be30504a4e1b","isSidechain":false,"promptId":"6e6c2140-4cee-4dea-b053-88ef3746e514","type":"user","message":{"role":"user","content":[{"tool_use_id":"toolu_016fpskgo3MTpnW9FjWJkfxV","type":"tool_result","content":"The file /Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/lineprotocol.go has been updated successfully."}]},"uuid":"da2bcb75-2034-48c6-af5b-37e07512749c","timestamp":"2026-03-18T05:09:34.020Z","toolUseResult":{"filePath":"/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/lineprotocol.go","oldString":"// decodeState holds the per-call scratch buffers used by DecodeLine.","newString":"// walDropped counts WAL messages dropped due to a full channel.\n// Logged periodically; not critical since binary snapshots capture the data.\nvar walDropped atomic.Int64\n\n// decodeState holds the per-call scratch buffers used by DecodeLine.","originalFile":"// Copyright (C) NHR@FAU, University Erlangen-Nuremberg.\n// All rights reserved. This file is part of cc-backend.\n// Use of this source code is governed by a MIT-style\n// license that can be found in the LICENSE file.\n\n// This file implements ingestion of InfluxDB line-protocol metric data received\n// over NATS. Each line encodes one metric sample with the following structure:\n//\n//\t[,cluster=][,hostname=][,type=][,type-id=][,subtype=][,stype-id=] value= []\n//\n// The measurement name identifies the metric (e.g. \"cpu_load\"). Tags provide\n// routing information (cluster, host) and optional sub-device selectors (type,\n// subtype). Only one field is expected per line: \"value\".\n//\n// After decoding, each sample is:\n// 1. Written to the in-memory store via ms.WriteToLevel.\n// 2. If the checkpoint format is \"wal\", also forwarded to the WAL staging\n// goroutine via the WALMessages channel for durable write-ahead logging.\npackage metricstore\n\nimport (\n\t\"bytes\"\n\t\"context\"\n\t\"fmt\"\n\t\"sync\"\n\t\"sync/atomic\"\n\t\"time\"\n\n\tcclog \"github.com/ClusterCockpit/cc-lib/v2/ccLogger\"\n\t\"github.com/ClusterCockpit/cc-lib/v2/nats\"\n\t\"github.com/ClusterCockpit/cc-lib/v2/schema\"\n\t\"github.com/ClusterCockpit/cc-line-protocol/v2/lineprotocol\"\n)\n\n// ReceiveNats subscribes to all configured NATS subjects and feeds incoming\n// line-protocol messages into the MemoryStore.\n//\n// When workers > 1 a pool of goroutines drains a shared channel so that\n// multiple messages can be decoded in parallel. With workers == 1 the NATS\n// callback decodes inline (no channel overhead, lower latency).\n//\n// The function blocks until ctx is cancelled and all worker goroutines have\n// finished. It returns nil when the NATS client is not configured; callers\n// should treat that as a no-op rather than an error.\nfunc ReceiveNats(ms *MemoryStore,\n\tworkers int,\n\tctx context.Context,\n) error {\n\tnc := nats.GetClient()\n\n\tif nc == nil {\n\t\tcclog.Warn(\"NATS client not initialized\")\n\t\treturn nil\n\t}\n\n\tvar wg sync.WaitGroup\n\tmsgs := make(chan []byte, max(workers*256, 8192))\n\n\tfor _, sc := range *Keys.Subscriptions {\n\t\tclusterTag := sc.ClusterTag\n\t\tif workers > 1 {\n\t\t\twg.Add(workers)\n\n\t\t\tfor range workers {\n\t\t\t\tgo func() {\n\t\t\t\t\tdefer wg.Done()\n\t\t\t\t\tfor m := range msgs {\n\t\t\t\t\t\tdec := lineprotocol.NewDecoderWithBytes(m)\n\t\t\t\t\t\tif err := DecodeLine(dec, ms, clusterTag); err != nil {\n\t\t\t\t\t\t\tcclog.Errorf(\"error: %s\", err.Error())\n\t\t\t\t\t\t}\n\t\t\t\t\t}\n\t\t\t\t}()\n\t\t\t}\n\n\t\t\tnc.Subscribe(sc.SubscribeTo, func(subject string, data []byte) {\n\t\t\t\tselect {\n\t\t\t\tcase msgs <- data:\n\t\t\t\tcase <-ctx.Done():\n\t\t\t\t}\n\t\t\t})\n\t\t} else {\n\t\t\tnc.Subscribe(sc.SubscribeTo, func(subject string, data []byte) {\n\t\t\t\tdec := lineprotocol.NewDecoderWithBytes(data)\n\t\t\t\tif err := DecodeLine(dec, ms, clusterTag); err != nil {\n\t\t\t\t\tcclog.Errorf(\"error: %s\", err.Error())\n\t\t\t\t}\n\t\t\t})\n\t\t}\n\t\tcclog.Infof(\"NATS subscription to '%s' established\", sc.SubscribeTo)\n\t}\n\n\tgo func() {\n\t\t<-ctx.Done()\n\t\tclose(msgs)\n\t}()\n\n\twg.Wait()\n\n\treturn nil\n}\n\n// reorder prepends prefix to buf in-place when buf has enough spare capacity,\n// avoiding an allocation. Falls back to a regular append otherwise.\n//\n// It is used to assemble the \"type\" and \"subtype\" selector\n// strings when the type tag arrives before the type-id tag in the line, so the\n// two byte slices need to be concatenated in tag-declaration order regardless\n// of wire order.\nfunc reorder(buf, prefix []byte) []byte {\n\tn := len(prefix)\n\tm := len(buf)\n\tif cap(buf) < m+n {\n\t\treturn append(prefix[:n:n], buf...)\n\t} else {\n\t\tbuf = buf[:n+m]\n\t\tfor i := m - 1; i >= 0; i-- {\n\t\t\tbuf[i+n] = buf[i]\n\t\t}\n\t\tfor i := range n {\n\t\t\tbuf[i] = prefix[i]\n\t\t}\n\t\treturn buf\n\t}\n}\n\n// decodeState holds the per-call scratch buffers used by DecodeLine.\n// Instances are recycled via decodeStatePool to avoid repeated allocations\n// during high-throughput ingestion.\ntype decodeState struct {\n\t// metricBuf holds a copy of the current measurement name (line-protocol\n\t// measurement field). Copied because dec.Measurement() returns a slice\n\t// that is invalidated by the next decoder call.\n\tmetricBuf []byte\n\n\t// selector is the sub-device path passed to WriteToLevel and WALMessage\n\t// (e.g. [\"socket0\"] or [\"socket0\", \"memctrl1\"]). Reused across lines.\n\tselector []string\n\n\t// typeBuf accumulates the concatenated \"type\"+\"type-id\" tag value for the\n\t// current line. Reset at the start of each line's tag-decode loop.\n\ttypeBuf []byte\n\n\t// subTypeBuf accumulates the concatenated \"subtype\"+\"stype-id\" tag value.\n\t// Reset at the start of each line's tag-decode loop.\n\tsubTypeBuf []byte\n\n\t// prevTypeBytes / prevTypeStr cache the last seen typeBuf content and its\n\t// string conversion. Because consecutive lines in a batch typically address\n\t// the same sub-device, the cache hit rate is very high and avoids\n\t// repeated []byte→string allocations.\n\tprevTypeBytes []byte\n\tprevTypeStr string\n\n\t// prevSubTypeBytes / prevSubTypeStr are the same cache for the subtype.\n\tprevSubTypeBytes []byte\n\tprevSubTypeStr string\n}\n\n// decodeStatePool recycles decodeState values across DecodeLine calls to\n// reduce GC pressure during sustained metric ingestion.\nvar decodeStatePool = sync.Pool{\n\tNew: func() any {\n\t\treturn &decodeState{\n\t\t\tmetricBuf: make([]byte, 0, 16),\n\t\t\tselector: make([]string, 0, 4),\n\t\t\ttypeBuf: make([]byte, 0, 16),\n\t\t\tsubTypeBuf: make([]byte, 0, 16),\n\t\t}\n\t},\n}\n\n// DecodeLine reads all lines from dec (InfluxDB line-protocol) and writes each\n// decoded metric sample into ms.\n//\n// clusterDefault is used as the cluster name for lines that do not carry a\n// \"cluster\" tag. Callers typically supply the ClusterTag value from the NATS\n// subscription configuration.\n//\n// Performance notes:\n// - A decodeState is obtained from decodeStatePool to reuse scratch buffers.\n// - The Level pointer (host-level node in the metric tree) is cached across\n// consecutive lines that share the same cluster+host pair to avoid\n// repeated lock acquisitions on the root and cluster levels.\n// - []byte→string conversions for type/subtype selectors are cached via\n// prevType*/prevSubType* fields because batches typically repeat the same\n// sub-device identifiers.\n// - Timestamp parsing tries Second precision first; if that fails it retries\n// Millisecond, Microsecond, and Nanosecond in turn. A missing timestamp\n// falls back to time.Now().\n//\n// When the checkpoint format is \"wal\" each successfully decoded sample is also\n// sent to WALMessages so the WAL staging goroutine can persist it durably\n// before the next binary snapshot.\nfunc DecodeLine(dec *lineprotocol.Decoder,\n\tms *MemoryStore,\n\tclusterDefault string,\n) error {\n\t// Reduce allocations in loop:\n\tt := time.Now()\n\tmetric := Metric{}\n\tst := decodeStatePool.Get().(*decodeState)\n\tdefer decodeStatePool.Put(st)\n\n\t// Optimize for the case where all lines in a \"batch\" are about the same\n\t// cluster and host. By using `WriteToLevel` (level = host), we do not need\n\t// to take the root- and cluster-level lock as often.\n\tvar lvl *Level = nil\n\tprevCluster, prevHost := \"\", \"\"\n\n\tvar ok bool\n\tfor dec.Next() {\n\t\trawmeasurement, err := dec.Measurement()\n\t\tif err != nil {\n\t\t\treturn err\n\t\t}\n\n\t\t// Needs to be copied because another call to dec.* would\n\t\t// invalidate the returned slice.\n\t\tst.metricBuf = append(st.metricBuf[:0], rawmeasurement...)\n\n\t\t// The go compiler optimizes map[string(byteslice)] lookups:\n\t\tmetric.MetricConfig, ok = ms.Metrics[string(rawmeasurement)]\n\t\tif !ok {\n\t\t\tcontinue\n\t\t}\n\n\t\tst.typeBuf, st.subTypeBuf = st.typeBuf[:0], st.subTypeBuf[:0]\n\t\tcluster, host := clusterDefault, \"\"\n\t\tfor {\n\t\t\tkey, val, err := dec.NextTag()\n\t\t\tif err != nil {\n\t\t\t\treturn err\n\t\t\t}\n\t\t\tif key == nil {\n\t\t\t\tbreak\n\t\t\t}\n\n\t\t\t// The go compiler optimizes string([]byte{...}) == \"...\":\n\t\t\tswitch string(key) {\n\t\t\tcase \"cluster\":\n\t\t\t\tif string(val) == prevCluster {\n\t\t\t\t\tcluster = prevCluster\n\t\t\t\t} else {\n\t\t\t\t\tcluster = string(val)\n\t\t\t\t\tlvl = nil\n\t\t\t\t}\n\t\t\tcase \"hostname\", \"host\":\n\t\t\t\tif string(val) == prevHost {\n\t\t\t\t\thost = prevHost\n\t\t\t\t} else {\n\t\t\t\t\thost = string(val)\n\t\t\t\t\tlvl = nil\n\t\t\t\t}\n\t\t\tcase \"type\":\n\t\t\t\tif string(val) == \"node\" {\n\t\t\t\t\tbreak\n\t\t\t\t}\n\n\t\t\t\t// We cannot be sure that the \"type\" tag comes before the \"type-id\" tag:\n\t\t\t\tif len(st.typeBuf) == 0 {\n\t\t\t\t\tst.typeBuf = append(st.typeBuf, val...)\n\t\t\t\t} else {\n\t\t\t\t\tst.typeBuf = reorder(st.typeBuf, val)\n\t\t\t\t}\n\t\t\tcase \"type-id\":\n\t\t\t\tst.typeBuf = append(st.typeBuf, val...)\n\t\t\tcase \"subtype\":\n\t\t\t\t// We cannot be sure that the \"subtype\" tag comes before the \"stype-id\" tag:\n\t\t\t\tif len(st.subTypeBuf) == 0 {\n\t\t\t\t\tst.subTypeBuf = append(st.subTypeBuf, val...)\n\t\t\t\t} else {\n\t\t\t\t\tst.subTypeBuf = reorder(st.subTypeBuf, val)\n\t\t\t\t}\n\t\t\tcase \"stype-id\":\n\t\t\t\tst.subTypeBuf = append(st.subTypeBuf, val...)\n\t\t\tdefault:\n\t\t\t}\n\t\t}\n\n\t\t// If the cluster or host changed, the lvl was set to nil\n\t\tif lvl == nil {\n\t\t\tst.selector = st.selector[:2]\n\t\t\tst.selector[0], st.selector[1] = cluster, host\n\t\t\tlvl = ms.GetLevel(st.selector)\n\t\t\tprevCluster, prevHost = cluster, host\n\t\t}\n\n\t\t// subtypes: cache []byte→string conversions; messages in a batch typically\n\t\t// share the same type/subtype so the hit rate is very high.\n\t\tst.selector = st.selector[:0]\n\t\tif len(st.typeBuf) > 0 {\n\t\t\tif !bytes.Equal(st.typeBuf, st.prevTypeBytes) {\n\t\t\t\tst.prevTypeBytes = append(st.prevTypeBytes[:0], st.typeBuf...)\n\t\t\t\tst.prevTypeStr = string(st.typeBuf)\n\t\t\t}\n\t\t\tst.selector = append(st.selector, st.prevTypeStr)\n\t\t\tif len(st.subTypeBuf) > 0 {\n\t\t\t\tif !bytes.Equal(st.subTypeBuf, st.prevSubTypeBytes) {\n\t\t\t\t\tst.prevSubTypeBytes = append(st.prevSubTypeBytes[:0], st.subTypeBuf...)\n\t\t\t\t\tst.prevSubTypeStr = string(st.subTypeBuf)\n\t\t\t\t}\n\t\t\t\tst.selector = append(st.selector, st.prevSubTypeStr)\n\t\t\t}\n\t\t}\n\n\t\tfor {\n\t\t\tkey, val, err := dec.NextField()\n\t\t\tif err != nil {\n\t\t\t\treturn err\n\t\t\t}\n\n\t\t\tif key == nil {\n\t\t\t\tbreak\n\t\t\t}\n\n\t\t\tif string(key) != \"value\" {\n\t\t\t\treturn fmt.Errorf(\"host %s: unknown field: '%s' (value: %#v)\", host, string(key), val)\n\t\t\t}\n\n\t\t\tif val.Kind() == lineprotocol.Float {\n\t\t\t\tmetric.Value = schema.Float(val.FloatV())\n\t\t\t} else if val.Kind() == lineprotocol.Int {\n\t\t\t\tmetric.Value = schema.Float(val.IntV())\n\t\t\t} else if val.Kind() == lineprotocol.Uint {\n\t\t\t\tmetric.Value = schema.Float(val.UintV())\n\t\t\t} else {\n\t\t\t\treturn fmt.Errorf(\"host %s: unsupported value type in message: %s\", host, val.Kind().String())\n\t\t\t}\n\t\t}\n\n\t\tif t, err = dec.Time(lineprotocol.Second, t); err != nil {\n\t\t\tt = time.Now()\n\t\t\tif t, err = dec.Time(lineprotocol.Millisecond, t); err != nil {\n\t\t\t\tt = time.Now()\n\t\t\t\tif t, err = dec.Time(lineprotocol.Microsecond, t); err != nil {\n\t\t\t\t\tt = time.Now()\n\t\t\t\t\tif t, err = dec.Time(lineprotocol.Nanosecond, t); err != nil {\n\t\t\t\t\t\treturn fmt.Errorf(\"host %s: timestamp : %#v with error : %#v\", host, t, err.Error())\n\t\t\t\t\t}\n\t\t\t\t}\n\t\t\t}\n\t\t}\n\n\t\tif err != nil {\n\t\t\treturn fmt.Errorf(\"host %s: timestamp : %#v with error : %#v\", host, t, err.Error())\n\t\t}\n\n\t\ttime := t.Unix()\n\n\t\tif Keys.Checkpoints.FileFormat == \"wal\" {\n\t\t\tWALMessages <- &WALMessage{\n\t\t\t\tMetricName: string(st.metricBuf),\n\t\t\t\tCluster: cluster,\n\t\t\t\tNode: host,\n\t\t\t\tSelector: append([]string{}, st.selector...),\n\t\t\t\tValue: metric.Value,\n\t\t\t\tTimestamp: time,\n\t\t\t}\n\t\t}\n\n\t\tif err := ms.WriteToLevel(lvl, st.selector, time, []Metric{metric}); err != nil {\n\t\t\tcclog.Warnf(\"write error for host %s metric %s at ts %d: %s\", host, string(st.metricBuf), time, err.Error())\n\t\t\tcontinue\n\t\t}\n\t}\n\treturn nil\n}\n","structuredPatch":[{"oldStart":124,"oldLines":6,"newStart":124,"newLines":10,"lines":[" }"," }"," ","+// walDropped counts WAL messages dropped due to a full channel.","+// Logged periodically; not critical since binary snapshots capture the data.","+var walDropped atomic.Int64","+"," // decodeState holds the per-call scratch buffers used by DecodeLine."," // Instances are recycled via decodeStatePool to avoid repeated allocations"," // during high-throughput ingestion."]}],"userModified":false,"replaceAll":false},"sourceToolAssistantUUID":"a144f71e-4dce-4572-bed1-be30504a4e1b","userType":"external","entrypoint":"cli","cwd":"/Users/jan/prg/ClusterCockpit/cc-backend","sessionId":"5eb20a94-f8df-4979-a0ae-2aa99bfad884","version":"2.1.78","gitBranch":"hotfix","slug":"bright-wandering-flurry"} +{"parentUuid":"da2bcb75-2034-48c6-af5b-37e07512749c","isSidechain":false,"message":{"model":"claude-opus-4-6","id":"msg_01LsbEvEuhW5hJWn8NsSLF3m","type":"message","role":"assistant","content":[{"type":"text","text":"Now replace the blocking WAL send with non-blocking:"}],"stop_reason":null,"stop_sequence":null,"usage":{"input_tokens":1,"cache_creation_input_tokens":347,"cache_read_input_tokens":51795,"cache_creation":{"ephemeral_5m_input_tokens":0,"ephemeral_1h_input_tokens":347},"output_tokens":1,"service_tier":"standard","inference_geo":"not_available"}},"requestId":"req_011CZ9y8v5QQqXvE1RUWAymU","type":"assistant","uuid":"268d9640-dd6b-4e08-8bea-e09b457a1bf9","timestamp":"2026-03-18T05:09:37.834Z","userType":"external","entrypoint":"cli","cwd":"/Users/jan/prg/ClusterCockpit/cc-backend","sessionId":"5eb20a94-f8df-4979-a0ae-2aa99bfad884","version":"2.1.78","gitBranch":"hotfix","slug":"bright-wandering-flurry"} +{"parentUuid":"268d9640-dd6b-4e08-8bea-e09b457a1bf9","isSidechain":false,"message":{"model":"claude-opus-4-6","id":"msg_01LsbEvEuhW5hJWn8NsSLF3m","type":"message","role":"assistant","content":[{"type":"tool_use","id":"toolu_01KMJz45VrKGSrQXqBxd4prj","name":"Edit","input":{"replace_all":false,"file_path":"/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/lineprotocol.go","old_string":"\t\tif Keys.Checkpoints.FileFormat == \"wal\" {\n\t\t\tWALMessages <- &WALMessage{\n\t\t\t\tMetricName: string(st.metricBuf),\n\t\t\t\tCluster: cluster,\n\t\t\t\tNode: host,\n\t\t\t\tSelector: append([]string{}, st.selector...),\n\t\t\t\tValue: metric.Value,\n\t\t\t\tTimestamp: time,\n\t\t\t}\n\t\t}","new_string":"\t\tif Keys.Checkpoints.FileFormat == \"wal\" {\n\t\t\tmsg := &WALMessage{\n\t\t\t\tMetricName: string(st.metricBuf),\n\t\t\t\tCluster: cluster,\n\t\t\t\tNode: host,\n\t\t\t\tSelector: append([]string{}, st.selector...),\n\t\t\t\tValue: metric.Value,\n\t\t\t\tTimestamp: time,\n\t\t\t}\n\t\t\tselect {\n\t\t\tcase WALMessages <- msg:\n\t\t\tdefault:\n\t\t\t\t// WAL channel full — metric is written to memory store but not WAL.\n\t\t\t\t// Next binary snapshot will capture it.\n\t\t\t\tif dropped := walDropped.Add(1); dropped%10000 == 1 {\n\t\t\t\t\tcclog.Warnf(\"[METRICSTORE]> WAL channel full, dropped %d messages (data safe in memory, next snapshot will capture)\", dropped)\n\t\t\t\t}\n\t\t\t}\n\t\t}"},"caller":{"type":"direct"}}],"stop_reason":"tool_use","stop_sequence":null,"usage":{"input_tokens":1,"cache_creation_input_tokens":347,"cache_read_input_tokens":51795,"output_tokens":453,"server_tool_use":{"web_search_requests":0,"web_fetch_requests":0},"service_tier":"standard","cache_creation":{"ephemeral_1h_input_tokens":347,"ephemeral_5m_input_tokens":0},"inference_geo":"","iterations":[],"speed":"standard"}},"requestId":"req_011CZ9y8v5QQqXvE1RUWAymU","type":"assistant","uuid":"2555135c-429a-4d7e-b758-db15bfe5ad87","timestamp":"2026-03-18T05:09:43.059Z","userType":"external","entrypoint":"cli","cwd":"/Users/jan/prg/ClusterCockpit/cc-backend","sessionId":"5eb20a94-f8df-4979-a0ae-2aa99bfad884","version":"2.1.78","gitBranch":"hotfix","slug":"bright-wandering-flurry"} +{"parentUuid":"2555135c-429a-4d7e-b758-db15bfe5ad87","isSidechain":false,"type":"progress","data":{"type":"hook_progress","hookEvent":"PostToolUse","hookName":"PostToolUse:Edit","command":"callback"},"parentToolUseID":"toolu_01KMJz45VrKGSrQXqBxd4prj","toolUseID":"toolu_01KMJz45VrKGSrQXqBxd4prj","timestamp":"2026-03-18T05:09:43.068Z","uuid":"b7942c1d-67e7-4539-9c0a-898fc17fdd3c","userType":"external","entrypoint":"cli","cwd":"/Users/jan/prg/ClusterCockpit/cc-backend","sessionId":"5eb20a94-f8df-4979-a0ae-2aa99bfad884","version":"2.1.78","gitBranch":"hotfix","slug":"bright-wandering-flurry"} +{"parentUuid":"2555135c-429a-4d7e-b758-db15bfe5ad87","isSidechain":false,"promptId":"6e6c2140-4cee-4dea-b053-88ef3746e514","type":"user","message":{"role":"user","content":[{"tool_use_id":"toolu_01KMJz45VrKGSrQXqBxd4prj","type":"tool_result","content":"The file /Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/lineprotocol.go has been updated successfully."}]},"uuid":"f7399cf1-bc1f-424e-9fc4-e0fbcff4f20b","timestamp":"2026-03-18T05:09:43.068Z","toolUseResult":{"filePath":"/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/lineprotocol.go","oldString":"\t\tif Keys.Checkpoints.FileFormat == \"wal\" {\n\t\t\tWALMessages <- &WALMessage{\n\t\t\t\tMetricName: string(st.metricBuf),\n\t\t\t\tCluster: cluster,\n\t\t\t\tNode: host,\n\t\t\t\tSelector: append([]string{}, st.selector...),\n\t\t\t\tValue: metric.Value,\n\t\t\t\tTimestamp: time,\n\t\t\t}\n\t\t}","newString":"\t\tif Keys.Checkpoints.FileFormat == \"wal\" {\n\t\t\tmsg := &WALMessage{\n\t\t\t\tMetricName: string(st.metricBuf),\n\t\t\t\tCluster: cluster,\n\t\t\t\tNode: host,\n\t\t\t\tSelector: append([]string{}, st.selector...),\n\t\t\t\tValue: metric.Value,\n\t\t\t\tTimestamp: time,\n\t\t\t}\n\t\t\tselect {\n\t\t\tcase WALMessages <- msg:\n\t\t\tdefault:\n\t\t\t\t// WAL channel full — metric is written to memory store but not WAL.\n\t\t\t\t// Next binary snapshot will capture it.\n\t\t\t\tif dropped := walDropped.Add(1); dropped%10000 == 1 {\n\t\t\t\t\tcclog.Warnf(\"[METRICSTORE]> WAL channel full, dropped %d messages (data safe in memory, next snapshot will capture)\", dropped)\n\t\t\t\t}\n\t\t\t}\n\t\t}","originalFile":"// Copyright (C) NHR@FAU, University Erlangen-Nuremberg.\n// All rights reserved. This file is part of cc-backend.\n// Use of this source code is governed by a MIT-style\n// license that can be found in the LICENSE file.\n\n// This file implements ingestion of InfluxDB line-protocol metric data received\n// over NATS. Each line encodes one metric sample with the following structure:\n//\n//\t[,cluster=][,hostname=][,type=][,type-id=][,subtype=][,stype-id=] value= []\n//\n// The measurement name identifies the metric (e.g. \"cpu_load\"). Tags provide\n// routing information (cluster, host) and optional sub-device selectors (type,\n// subtype). Only one field is expected per line: \"value\".\n//\n// After decoding, each sample is:\n// 1. Written to the in-memory store via ms.WriteToLevel.\n// 2. If the checkpoint format is \"wal\", also forwarded to the WAL staging\n// goroutine via the WALMessages channel for durable write-ahead logging.\npackage metricstore\n\nimport (\n\t\"bytes\"\n\t\"context\"\n\t\"fmt\"\n\t\"sync\"\n\t\"sync/atomic\"\n\t\"time\"\n\n\tcclog \"github.com/ClusterCockpit/cc-lib/v2/ccLogger\"\n\t\"github.com/ClusterCockpit/cc-lib/v2/nats\"\n\t\"github.com/ClusterCockpit/cc-lib/v2/schema\"\n\t\"github.com/ClusterCockpit/cc-line-protocol/v2/lineprotocol\"\n)\n\n// ReceiveNats subscribes to all configured NATS subjects and feeds incoming\n// line-protocol messages into the MemoryStore.\n//\n// When workers > 1 a pool of goroutines drains a shared channel so that\n// multiple messages can be decoded in parallel. With workers == 1 the NATS\n// callback decodes inline (no channel overhead, lower latency).\n//\n// The function blocks until ctx is cancelled and all worker goroutines have\n// finished. It returns nil when the NATS client is not configured; callers\n// should treat that as a no-op rather than an error.\nfunc ReceiveNats(ms *MemoryStore,\n\tworkers int,\n\tctx context.Context,\n) error {\n\tnc := nats.GetClient()\n\n\tif nc == nil {\n\t\tcclog.Warn(\"NATS client not initialized\")\n\t\treturn nil\n\t}\n\n\tvar wg sync.WaitGroup\n\tmsgs := make(chan []byte, max(workers*256, 8192))\n\n\tfor _, sc := range *Keys.Subscriptions {\n\t\tclusterTag := sc.ClusterTag\n\t\tif workers > 1 {\n\t\t\twg.Add(workers)\n\n\t\t\tfor range workers {\n\t\t\t\tgo func() {\n\t\t\t\t\tdefer wg.Done()\n\t\t\t\t\tfor m := range msgs {\n\t\t\t\t\t\tdec := lineprotocol.NewDecoderWithBytes(m)\n\t\t\t\t\t\tif err := DecodeLine(dec, ms, clusterTag); err != nil {\n\t\t\t\t\t\t\tcclog.Errorf(\"error: %s\", err.Error())\n\t\t\t\t\t\t}\n\t\t\t\t\t}\n\t\t\t\t}()\n\t\t\t}\n\n\t\t\tnc.Subscribe(sc.SubscribeTo, func(subject string, data []byte) {\n\t\t\t\tselect {\n\t\t\t\tcase msgs <- data:\n\t\t\t\tcase <-ctx.Done():\n\t\t\t\t}\n\t\t\t})\n\t\t} else {\n\t\t\tnc.Subscribe(sc.SubscribeTo, func(subject string, data []byte) {\n\t\t\t\tdec := lineprotocol.NewDecoderWithBytes(data)\n\t\t\t\tif err := DecodeLine(dec, ms, clusterTag); err != nil {\n\t\t\t\t\tcclog.Errorf(\"error: %s\", err.Error())\n\t\t\t\t}\n\t\t\t})\n\t\t}\n\t\tcclog.Infof(\"NATS subscription to '%s' established\", sc.SubscribeTo)\n\t}\n\n\tgo func() {\n\t\t<-ctx.Done()\n\t\tclose(msgs)\n\t}()\n\n\twg.Wait()\n\n\treturn nil\n}\n\n// reorder prepends prefix to buf in-place when buf has enough spare capacity,\n// avoiding an allocation. Falls back to a regular append otherwise.\n//\n// It is used to assemble the \"type\" and \"subtype\" selector\n// strings when the type tag arrives before the type-id tag in the line, so the\n// two byte slices need to be concatenated in tag-declaration order regardless\n// of wire order.\nfunc reorder(buf, prefix []byte) []byte {\n\tn := len(prefix)\n\tm := len(buf)\n\tif cap(buf) < m+n {\n\t\treturn append(prefix[:n:n], buf...)\n\t} else {\n\t\tbuf = buf[:n+m]\n\t\tfor i := m - 1; i >= 0; i-- {\n\t\t\tbuf[i+n] = buf[i]\n\t\t}\n\t\tfor i := range n {\n\t\t\tbuf[i] = prefix[i]\n\t\t}\n\t\treturn buf\n\t}\n}\n\n// walDropped counts WAL messages dropped due to a full channel.\n// Logged periodically; not critical since binary snapshots capture the data.\nvar walDropped atomic.Int64\n\n// decodeState holds the per-call scratch buffers used by DecodeLine.\n// Instances are recycled via decodeStatePool to avoid repeated allocations\n// during high-throughput ingestion.\ntype decodeState struct {\n\t// metricBuf holds a copy of the current measurement name (line-protocol\n\t// measurement field). Copied because dec.Measurement() returns a slice\n\t// that is invalidated by the next decoder call.\n\tmetricBuf []byte\n\n\t// selector is the sub-device path passed to WriteToLevel and WALMessage\n\t// (e.g. [\"socket0\"] or [\"socket0\", \"memctrl1\"]). Reused across lines.\n\tselector []string\n\n\t// typeBuf accumulates the concatenated \"type\"+\"type-id\" tag value for the\n\t// current line. Reset at the start of each line's tag-decode loop.\n\ttypeBuf []byte\n\n\t// subTypeBuf accumulates the concatenated \"subtype\"+\"stype-id\" tag value.\n\t// Reset at the start of each line's tag-decode loop.\n\tsubTypeBuf []byte\n\n\t// prevTypeBytes / prevTypeStr cache the last seen typeBuf content and its\n\t// string conversion. Because consecutive lines in a batch typically address\n\t// the same sub-device, the cache hit rate is very high and avoids\n\t// repeated []byte→string allocations.\n\tprevTypeBytes []byte\n\tprevTypeStr string\n\n\t// prevSubTypeBytes / prevSubTypeStr are the same cache for the subtype.\n\tprevSubTypeBytes []byte\n\tprevSubTypeStr string\n}\n\n// decodeStatePool recycles decodeState values across DecodeLine calls to\n// reduce GC pressure during sustained metric ingestion.\nvar decodeStatePool = sync.Pool{\n\tNew: func() any {\n\t\treturn &decodeState{\n\t\t\tmetricBuf: make([]byte, 0, 16),\n\t\t\tselector: make([]string, 0, 4),\n\t\t\ttypeBuf: make([]byte, 0, 16),\n\t\t\tsubTypeBuf: make([]byte, 0, 16),\n\t\t}\n\t},\n}\n\n// DecodeLine reads all lines from dec (InfluxDB line-protocol) and writes each\n// decoded metric sample into ms.\n//\n// clusterDefault is used as the cluster name for lines that do not carry a\n// \"cluster\" tag. Callers typically supply the ClusterTag value from the NATS\n// subscription configuration.\n//\n// Performance notes:\n// - A decodeState is obtained from decodeStatePool to reuse scratch buffers.\n// - The Level pointer (host-level node in the metric tree) is cached across\n// consecutive lines that share the same cluster+host pair to avoid\n// repeated lock acquisitions on the root and cluster levels.\n// - []byte→string conversions for type/subtype selectors are cached via\n// prevType*/prevSubType* fields because batches typically repeat the same\n// sub-device identifiers.\n// - Timestamp parsing tries Second precision first; if that fails it retries\n// Millisecond, Microsecond, and Nanosecond in turn. A missing timestamp\n// falls back to time.Now().\n//\n// When the checkpoint format is \"wal\" each successfully decoded sample is also\n// sent to WALMessages so the WAL staging goroutine can persist it durably\n// before the next binary snapshot.\nfunc DecodeLine(dec *lineprotocol.Decoder,\n\tms *MemoryStore,\n\tclusterDefault string,\n) error {\n\t// Reduce allocations in loop:\n\tt := time.Now()\n\tmetric := Metric{}\n\tst := decodeStatePool.Get().(*decodeState)\n\tdefer decodeStatePool.Put(st)\n\n\t// Optimize for the case where all lines in a \"batch\" are about the same\n\t// cluster and host. By using `WriteToLevel` (level = host), we do not need\n\t// to take the root- and cluster-level lock as often.\n\tvar lvl *Level = nil\n\tprevCluster, prevHost := \"\", \"\"\n\n\tvar ok bool\n\tfor dec.Next() {\n\t\trawmeasurement, err := dec.Measurement()\n\t\tif err != nil {\n\t\t\treturn err\n\t\t}\n\n\t\t// Needs to be copied because another call to dec.* would\n\t\t// invalidate the returned slice.\n\t\tst.metricBuf = append(st.metricBuf[:0], rawmeasurement...)\n\n\t\t// The go compiler optimizes map[string(byteslice)] lookups:\n\t\tmetric.MetricConfig, ok = ms.Metrics[string(rawmeasurement)]\n\t\tif !ok {\n\t\t\tcontinue\n\t\t}\n\n\t\tst.typeBuf, st.subTypeBuf = st.typeBuf[:0], st.subTypeBuf[:0]\n\t\tcluster, host := clusterDefault, \"\"\n\t\tfor {\n\t\t\tkey, val, err := dec.NextTag()\n\t\t\tif err != nil {\n\t\t\t\treturn err\n\t\t\t}\n\t\t\tif key == nil {\n\t\t\t\tbreak\n\t\t\t}\n\n\t\t\t// The go compiler optimizes string([]byte{...}) == \"...\":\n\t\t\tswitch string(key) {\n\t\t\tcase \"cluster\":\n\t\t\t\tif string(val) == prevCluster {\n\t\t\t\t\tcluster = prevCluster\n\t\t\t\t} else {\n\t\t\t\t\tcluster = string(val)\n\t\t\t\t\tlvl = nil\n\t\t\t\t}\n\t\t\tcase \"hostname\", \"host\":\n\t\t\t\tif string(val) == prevHost {\n\t\t\t\t\thost = prevHost\n\t\t\t\t} else {\n\t\t\t\t\thost = string(val)\n\t\t\t\t\tlvl = nil\n\t\t\t\t}\n\t\t\tcase \"type\":\n\t\t\t\tif string(val) == \"node\" {\n\t\t\t\t\tbreak\n\t\t\t\t}\n\n\t\t\t\t// We cannot be sure that the \"type\" tag comes before the \"type-id\" tag:\n\t\t\t\tif len(st.typeBuf) == 0 {\n\t\t\t\t\tst.typeBuf = append(st.typeBuf, val...)\n\t\t\t\t} else {\n\t\t\t\t\tst.typeBuf = reorder(st.typeBuf, val)\n\t\t\t\t}\n\t\t\tcase \"type-id\":\n\t\t\t\tst.typeBuf = append(st.typeBuf, val...)\n\t\t\tcase \"subtype\":\n\t\t\t\t// We cannot be sure that the \"subtype\" tag comes before the \"stype-id\" tag:\n\t\t\t\tif len(st.subTypeBuf) == 0 {\n\t\t\t\t\tst.subTypeBuf = append(st.subTypeBuf, val...)\n\t\t\t\t} else {\n\t\t\t\t\tst.subTypeBuf = reorder(st.subTypeBuf, val)\n\t\t\t\t}\n\t\t\tcase \"stype-id\":\n\t\t\t\tst.subTypeBuf = append(st.subTypeBuf, val...)\n\t\t\tdefault:\n\t\t\t}\n\t\t}\n\n\t\t// If the cluster or host changed, the lvl was set to nil\n\t\tif lvl == nil {\n\t\t\tst.selector = st.selector[:2]\n\t\t\tst.selector[0], st.selector[1] = cluster, host\n\t\t\tlvl = ms.GetLevel(st.selector)\n\t\t\tprevCluster, prevHost = cluster, host\n\t\t}\n\n\t\t// subtypes: cache []byte→string conversions; messages in a batch typically\n\t\t// share the same type/subtype so the hit rate is very high.\n\t\tst.selector = st.selector[:0]\n\t\tif len(st.typeBuf) > 0 {\n\t\t\tif !bytes.Equal(st.typeBuf, st.prevTypeBytes) {\n\t\t\t\tst.prevTypeBytes = append(st.prevTypeBytes[:0], st.typeBuf...)\n\t\t\t\tst.prevTypeStr = string(st.typeBuf)\n\t\t\t}\n\t\t\tst.selector = append(st.selector, st.prevTypeStr)\n\t\t\tif len(st.subTypeBuf) > 0 {\n\t\t\t\tif !bytes.Equal(st.subTypeBuf, st.prevSubTypeBytes) {\n\t\t\t\t\tst.prevSubTypeBytes = append(st.prevSubTypeBytes[:0], st.subTypeBuf...)\n\t\t\t\t\tst.prevSubTypeStr = string(st.subTypeBuf)\n\t\t\t\t}\n\t\t\t\tst.selector = append(st.selector, st.prevSubTypeStr)\n\t\t\t}\n\t\t}\n\n\t\tfor {\n\t\t\tkey, val, err := dec.NextField()\n\t\t\tif err != nil {\n\t\t\t\treturn err\n\t\t\t}\n\n\t\t\tif key == nil {\n\t\t\t\tbreak\n\t\t\t}\n\n\t\t\tif string(key) != \"value\" {\n\t\t\t\treturn fmt.Errorf(\"host %s: unknown field: '%s' (value: %#v)\", host, string(key), val)\n\t\t\t}\n\n\t\t\tif val.Kind() == lineprotocol.Float {\n\t\t\t\tmetric.Value = schema.Float(val.FloatV())\n\t\t\t} else if val.Kind() == lineprotocol.Int {\n\t\t\t\tmetric.Value = schema.Float(val.IntV())\n\t\t\t} else if val.Kind() == lineprotocol.Uint {\n\t\t\t\tmetric.Value = schema.Float(val.UintV())\n\t\t\t} else {\n\t\t\t\treturn fmt.Errorf(\"host %s: unsupported value type in message: %s\", host, val.Kind().String())\n\t\t\t}\n\t\t}\n\n\t\tif t, err = dec.Time(lineprotocol.Second, t); err != nil {\n\t\t\tt = time.Now()\n\t\t\tif t, err = dec.Time(lineprotocol.Millisecond, t); err != nil {\n\t\t\t\tt = time.Now()\n\t\t\t\tif t, err = dec.Time(lineprotocol.Microsecond, t); err != nil {\n\t\t\t\t\tt = time.Now()\n\t\t\t\t\tif t, err = dec.Time(lineprotocol.Nanosecond, t); err != nil {\n\t\t\t\t\t\treturn fmt.Errorf(\"host %s: timestamp : %#v with error : %#v\", host, t, err.Error())\n\t\t\t\t\t}\n\t\t\t\t}\n\t\t\t}\n\t\t}\n\n\t\tif err != nil {\n\t\t\treturn fmt.Errorf(\"host %s: timestamp : %#v with error : %#v\", host, t, err.Error())\n\t\t}\n\n\t\ttime := t.Unix()\n\n\t\tif Keys.Checkpoints.FileFormat == \"wal\" {\n\t\t\tWALMessages <- &WALMessage{\n\t\t\t\tMetricName: string(st.metricBuf),\n\t\t\t\tCluster: cluster,\n\t\t\t\tNode: host,\n\t\t\t\tSelector: append([]string{}, st.selector...),\n\t\t\t\tValue: metric.Value,\n\t\t\t\tTimestamp: time,\n\t\t\t}\n\t\t}\n\n\t\tif err := ms.WriteToLevel(lvl, st.selector, time, []Metric{metric}); err != nil {\n\t\t\tcclog.Warnf(\"write error for host %s metric %s at ts %d: %s\", host, string(st.metricBuf), time, err.Error())\n\t\t\tcontinue\n\t\t}\n\t}\n\treturn nil\n}\n","structuredPatch":[{"oldStart":353,"oldLines":7,"newStart":353,"newLines":7,"lines":[" time := t.Unix()"," "," if Keys.Checkpoints.FileFormat == \"wal\" {","- WALMessages <- &WALMessage{","+ msg := &WALMessage{"," MetricName: string(st.metricBuf),"," Cluster: cluster,"," Node: host,"]},{"oldStart":361,"oldLines":6,"newStart":361,"newLines":15,"lines":[" Value: metric.Value,"," Timestamp: time,"," }","+ select {","+ case WALMessages <- msg:","+ default:","+ // WAL channel full — metric is written to memory store but not WAL.","+ // Next binary snapshot will capture it.","+ if dropped := walDropped.Add(1); dropped%10000 == 1 {","+ cclog.Warnf(\"[METRICSTORE]> WAL channel full, dropped %d messages (data safe in memory, next snapshot will capture)\", dropped)","+ }","+ }"," }"," "," if err := ms.WriteToLevel(lvl, st.selector, time, []Metric{metric}); err != nil {"]}],"userModified":false,"replaceAll":false},"sourceToolAssistantUUID":"2555135c-429a-4d7e-b758-db15bfe5ad87","userType":"external","entrypoint":"cli","cwd":"/Users/jan/prg/ClusterCockpit/cc-backend","sessionId":"5eb20a94-f8df-4979-a0ae-2aa99bfad884","version":"2.1.78","gitBranch":"hotfix","slug":"bright-wandering-flurry"} +{"parentUuid":"f7399cf1-bc1f-424e-9fc4-e0fbcff4f20b","isSidechain":false,"message":{"model":"claude-opus-4-6","id":"msg_01QGaPxFtvShofkVtHM9esHz","type":"message","role":"assistant","content":[{"type":"text","text":"**Change 4:** Batch WAL drain in `WALStaging`. Replace the main loop to drain multiple messages per iteration:"}],"stop_reason":null,"stop_sequence":null,"usage":{"input_tokens":1,"cache_creation_input_tokens":571,"cache_read_input_tokens":52142,"cache_creation":{"ephemeral_5m_input_tokens":0,"ephemeral_1h_input_tokens":571},"output_tokens":1,"service_tier":"standard","inference_geo":"not_available"}},"requestId":"req_011CZ9y9avW9jpyDY24wAhJH","type":"assistant","uuid":"be1fc502-6259-4340-a838-25233a343f64","timestamp":"2026-03-18T05:09:49.262Z","userType":"external","entrypoint":"cli","cwd":"/Users/jan/prg/ClusterCockpit/cc-backend","sessionId":"5eb20a94-f8df-4979-a0ae-2aa99bfad884","version":"2.1.78","gitBranch":"hotfix","slug":"bright-wandering-flurry"} +{"parentUuid":"be1fc502-6259-4340-a838-25233a343f64","isSidechain":false,"message":{"model":"claude-opus-4-6","id":"msg_01QGaPxFtvShofkVtHM9esHz","type":"message","role":"assistant","content":[{"type":"tool_use","id":"toolu_01VWzrTY53uRmUDrHYgv28TZ","name":"Edit","input":{"replace_all":false,"file_path":"/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/walCheckpoint.go","old_string":"\t\tfor {\n\t\t\tselect {\n\t\t\tcase <-ctx.Done():\n\t\t\t\tdrain()\n\t\t\t\treturn\n\t\t\tcase msg, ok := <-WALMessages:\n\t\t\t\tif !ok {\n\t\t\t\t\treturn\n\t\t\t\t}\n\t\t\t\tprocessMsg(msg)\n\t\t\tcase req := <-walRotateCh:\n\t\t\t\tprocessRotate(req)\n\t\t\t}\n\t\t}","new_string":"\t\tfor {\n\t\t\tselect {\n\t\t\tcase <-ctx.Done():\n\t\t\t\tdrain()\n\t\t\t\treturn\n\t\t\tcase msg, ok := <-WALMessages:\n\t\t\t\tif !ok {\n\t\t\t\t\treturn\n\t\t\t\t}\n\t\t\t\tprocessMsg(msg)\n\n\t\t\t\t// Drain up to 256 more messages without blocking to batch writes.\n\t\t\t\tfor range 256 {\n\t\t\t\t\tselect {\n\t\t\t\t\tcase msg, ok := <-WALMessages:\n\t\t\t\t\t\tif !ok {\n\t\t\t\t\t\t\treturn\n\t\t\t\t\t\t}\n\t\t\t\t\t\tprocessMsg(msg)\n\t\t\t\t\tcase req := <-walRotateCh:\n\t\t\t\t\t\tprocessRotate(req)\n\t\t\t\t\tdefault:\n\t\t\t\t\t\tgoto flushed\n\t\t\t\t\t}\n\t\t\t\t}\n\t\t\tflushed:\n\t\t\t\t// Flush all buffered writers after processing the batch.\n\t\t\t\tfor _, ws := range hostFiles {\n\t\t\t\t\tif ws.f != nil {\n\t\t\t\t\t\tws.w.Flush()\n\t\t\t\t\t}\n\t\t\t\t}\n\t\t\tcase req := <-walRotateCh:\n\t\t\t\tprocessRotate(req)\n\t\t\t}\n\t\t}"},"caller":{"type":"direct"}}],"stop_reason":"tool_use","stop_sequence":null,"usage":{"input_tokens":1,"cache_creation_input_tokens":571,"cache_read_input_tokens":52142,"output_tokens":480,"server_tool_use":{"web_search_requests":0,"web_fetch_requests":0},"service_tier":"standard","cache_creation":{"ephemeral_1h_input_tokens":571,"ephemeral_5m_input_tokens":0},"inference_geo":"","iterations":[],"speed":"standard"}},"requestId":"req_011CZ9y9avW9jpyDY24wAhJH","type":"assistant","uuid":"dc2282bb-a59e-4924-8bd9-8ec3771a318f","timestamp":"2026-03-18T05:09:53.861Z","userType":"external","entrypoint":"cli","cwd":"/Users/jan/prg/ClusterCockpit/cc-backend","sessionId":"5eb20a94-f8df-4979-a0ae-2aa99bfad884","version":"2.1.78","gitBranch":"hotfix","slug":"bright-wandering-flurry"} +{"parentUuid":"dc2282bb-a59e-4924-8bd9-8ec3771a318f","isSidechain":false,"type":"progress","data":{"type":"hook_progress","hookEvent":"PostToolUse","hookName":"PostToolUse:Edit","command":"callback"},"parentToolUseID":"toolu_01VWzrTY53uRmUDrHYgv28TZ","toolUseID":"toolu_01VWzrTY53uRmUDrHYgv28TZ","timestamp":"2026-03-18T05:09:53.872Z","uuid":"d4aae964-7c89-42f7-bbdf-b09c37c09cc3","userType":"external","entrypoint":"cli","cwd":"/Users/jan/prg/ClusterCockpit/cc-backend","sessionId":"5eb20a94-f8df-4979-a0ae-2aa99bfad884","version":"2.1.78","gitBranch":"hotfix","slug":"bright-wandering-flurry"} +{"parentUuid":"dc2282bb-a59e-4924-8bd9-8ec3771a318f","isSidechain":false,"promptId":"6e6c2140-4cee-4dea-b053-88ef3746e514","type":"user","message":{"role":"user","content":[{"tool_use_id":"toolu_01VWzrTY53uRmUDrHYgv28TZ","type":"tool_result","content":"The file /Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/walCheckpoint.go has been updated successfully."}]},"uuid":"0bb50aad-bae3-4297-bb66-e7f853d8063f","timestamp":"2026-03-18T05:09:53.871Z","toolUseResult":{"filePath":"/Users/jan/prg/ClusterCockpit/cc-backend/pkg/metricstore/walCheckpoint.go","oldString":"\t\tfor {\n\t\t\tselect {\n\t\t\tcase <-ctx.Done():\n\t\t\t\tdrain()\n\t\t\t\treturn\n\t\t\tcase msg, ok := <-WALMessages:\n\t\t\t\tif !ok {\n\t\t\t\t\treturn\n\t\t\t\t}\n\t\t\t\tprocessMsg(msg)\n\t\t\tcase req := <-walRotateCh:\n\t\t\t\tprocessRotate(req)\n\t\t\t}\n\t\t}","newString":"\t\tfor {\n\t\t\tselect {\n\t\t\tcase <-ctx.Done():\n\t\t\t\tdrain()\n\t\t\t\treturn\n\t\t\tcase msg, ok := <-WALMessages:\n\t\t\t\tif !ok {\n\t\t\t\t\treturn\n\t\t\t\t}\n\t\t\t\tprocessMsg(msg)\n\n\t\t\t\t// Drain up to 256 more messages without blocking to batch writes.\n\t\t\t\tfor range 256 {\n\t\t\t\t\tselect {\n\t\t\t\t\tcase msg, ok := <-WALMessages:\n\t\t\t\t\t\tif !ok {\n\t\t\t\t\t\t\treturn\n\t\t\t\t\t\t}\n\t\t\t\t\t\tprocessMsg(msg)\n\t\t\t\t\tcase req := <-walRotateCh:\n\t\t\t\t\t\tprocessRotate(req)\n\t\t\t\t\tdefault:\n\t\t\t\t\t\tgoto flushed\n\t\t\t\t\t}\n\t\t\t\t}\n\t\t\tflushed:\n\t\t\t\t// Flush all buffered writers after processing the batch.\n\t\t\t\tfor _, ws := range hostFiles {\n\t\t\t\t\tif ws.f != nil {\n\t\t\t\t\t\tws.w.Flush()\n\t\t\t\t\t}\n\t\t\t\t}\n\t\t\tcase req := <-walRotateCh:\n\t\t\t\tprocessRotate(req)\n\t\t\t}\n\t\t}","originalFile":"// Copyright (C) NHR@FAU, University Erlangen-Nuremberg.\n// All rights reserved. This file is part of cc-backend.\n// Use of this source code is governed by a MIT-style\n// license that can be found in the LICENSE file.\n\n// Package metricstore provides walCheckpoint.go: WAL-based checkpoint implementation.\n//\n// This replaces the Avro shadow tree with an append-only Write-Ahead Log (WAL)\n// per host, eliminating the extra memory overhead of the AvroStore and providing\n// truly continuous (per-write) crash safety.\n//\n// # Architecture\n//\n//\tMetric write (DecodeLine)\n//\t │\n//\t ├─► WriteToLevel() → main MemoryStore (unchanged)\n//\t │\n//\t └─► WALMessages channel\n//\t │\n//\t ▼\n//\t WALStaging goroutine\n//\t │\n//\t ▼\n//\t checkpoints/cluster/host/current.wal (append-only, binary)\n//\n//\tPeriodic checkpoint (Checkpointing goroutine):\n//\t 1. Write .bin snapshot (column-oriented, from main tree)\n//\t 2. Signal WALStaging to truncate current.wal per host\n//\n//\tOn restart (FromCheckpoint):\n//\t 1. Load most recent .bin snapshot\n//\t 2. Replay current.wal (overwrite-safe: buffer.write handles duplicate timestamps)\n//\n// # WAL Record Format\n//\n//\t[4B magic 0xCC1DA7A1][4B payload_len][payload][4B CRC32]\n//\n//\tpayload:\n//\t [8B timestamp int64]\n//\t [2B metric_name_len uint16][N metric name bytes]\n//\t [1B selector_count uint8]\n//\t per selector: [1B selector_len uint8][M selector bytes]\n//\t [4B value float32 bits]\n//\n// # Binary Snapshot Format\n//\n//\t[4B magic 0xCC5B0001][8B from int64][8B to int64]\n//\tLevel tree (recursive):\n//\t [4B num_metrics uint32]\n//\t per metric:\n//\t [2B name_len uint16][N name bytes]\n//\t [8B frequency int64][8B start int64]\n//\t [4B num_values uint32][num_values × 4B float32]\n//\t [4B num_children uint32]\n//\t per child: [2B name_len uint16][N name bytes] + Level (recursive)\npackage metricstore\n\nimport (\n\t\"bufio\"\n\t\"context\"\n\t\"encoding/binary\"\n\t\"fmt\"\n\t\"hash/crc32\"\n\t\"io\"\n\t\"math\"\n\t\"os\"\n\t\"path\"\n\t\"strings\"\n\t\"sync\"\n\t\"sync/atomic\"\n\n\tcclog \"github.com/ClusterCockpit/cc-lib/v2/ccLogger\"\n\t\"github.com/ClusterCockpit/cc-lib/v2/schema\"\n)\n\n// Magic numbers for binary formats.\nconst (\n\twalFileMagic = uint32(0xCC1DA701) // WAL file header magic\n\twalRecordMagic = uint32(0xCC1DA7A1) // WAL record magic\n\tsnapFileMagic = uint32(0xCC5B0001) // Binary snapshot magic\n)\n\n// WALMessages is the channel for sending metric writes to the WAL staging goroutine.\n// Buffered to allow burst writes without blocking the metric ingestion path.\nvar WALMessages = make(chan *WALMessage, 65536)\n\n// walRotateCh is used by the checkpoint goroutine to request WAL file rotation\n// (close, delete, reopen) after a binary snapshot has been written.\nvar walRotateCh = make(chan walRotateReq, 256)\n\n// WALMessage represents a single metric write to be appended to the WAL.\n// Cluster and Node are NOT stored in the WAL record (inferred from file path).\ntype WALMessage struct {\n\tMetricName string\n\tCluster string\n\tNode string\n\tSelector []string\n\tValue schema.Float\n\tTimestamp int64\n}\n\n// walRotateReq requests WAL file rotation for a specific host directory.\n// The done channel is closed by the WAL goroutine when rotation is complete.\ntype walRotateReq struct {\n\thostDir string\n\tdone chan struct{}\n}\n\n// walFileState holds an open WAL file handle and buffered writer for one host directory.\ntype walFileState struct {\n\tf *os.File\n\tw *bufio.Writer\n}\n\n// WALStaging starts a background goroutine that receives WALMessage items\n// and appends binary WAL records to per-host current.wal files.\n// Also handles WAL rotation requests from the checkpoint goroutine.\nfunc WALStaging(wg *sync.WaitGroup, ctx context.Context) {\n\twg.Go(func() {\n\t\tif Keys.Checkpoints.FileFormat == \"json\" {\n\t\t\treturn\n\t\t}\n\n\t\thostFiles := make(map[string]*walFileState)\n\n\t\tdefer func() {\n\t\t\tfor _, ws := range hostFiles {\n\t\t\t\tif ws.f != nil {\n\t\t\t\t\tws.w.Flush()\n\t\t\t\t\tws.f.Close()\n\t\t\t\t}\n\t\t\t}\n\t\t}()\n\n\t\tgetOrOpenWAL := func(hostDir string) *walFileState {\n\t\t\tws, ok := hostFiles[hostDir]\n\t\t\tif ok {\n\t\t\t\treturn ws\n\t\t\t}\n\n\t\t\tif err := os.MkdirAll(hostDir, CheckpointDirPerms); err != nil {\n\t\t\t\tcclog.Errorf(\"[METRICSTORE]> WAL: mkdir %s: %v\", hostDir, err)\n\t\t\t\treturn nil\n\t\t\t}\n\n\t\t\twalPath := path.Join(hostDir, \"current.wal\")\n\t\t\tf, err := os.OpenFile(walPath, os.O_CREATE|os.O_APPEND|os.O_WRONLY, CheckpointFilePerms)\n\t\t\tif err != nil {\n\t\t\t\tcclog.Errorf(\"[METRICSTORE]> WAL: open %s: %v\", walPath, err)\n\t\t\t\treturn nil\n\t\t\t}\n\n\t\t\tw := bufio.NewWriter(f)\n\n\t\t\t// Write file header magic if file is new (empty).\n\t\t\tinfo, err := f.Stat()\n\t\t\tif err == nil && info.Size() == 0 {\n\t\t\t\tvar hdr [4]byte\n\t\t\t\tbinary.LittleEndian.PutUint32(hdr[:], walFileMagic)\n\t\t\t\tif _, err := w.Write(hdr[:]); err != nil {\n\t\t\t\t\tcclog.Errorf(\"[METRICSTORE]> WAL: write header %s: %v\", walPath, err)\n\t\t\t\t\tf.Close()\n\t\t\t\t\treturn nil\n\t\t\t\t}\n\t\t\t}\n\n\t\t\tws = &walFileState{f: f, w: w}\n\t\t\thostFiles[hostDir] = ws\n\t\t\treturn ws\n\t\t}\n\n\t\tprocessMsg := func(msg *WALMessage) {\n\t\t\thostDir := path.Join(Keys.Checkpoints.RootDir, msg.Cluster, msg.Node)\n\t\t\tws := getOrOpenWAL(hostDir)\n\t\t\tif ws == nil {\n\t\t\t\treturn\n\t\t\t}\n\t\t\tif err := writeWALRecord(ws.w, msg); err != nil {\n\t\t\t\tcclog.Errorf(\"[METRICSTORE]> WAL: write record: %v\", err)\n\t\t\t}\n\t\t}\n\n\t\tprocessRotate := func(req walRotateReq) {\n\t\t\tws, ok := hostFiles[req.hostDir]\n\t\t\tif ok && ws.f != nil {\n\t\t\t\tws.w.Flush()\n\t\t\t\tws.f.Close()\n\t\t\t\twalPath := path.Join(req.hostDir, \"current.wal\")\n\t\t\t\tif err := os.Remove(walPath); err != nil && !os.IsNotExist(err) {\n\t\t\t\t\tcclog.Errorf(\"[METRICSTORE]> WAL: remove %s: %v\", walPath, err)\n\t\t\t\t}\n\t\t\t\tdelete(hostFiles, req.hostDir)\n\t\t\t}\n\t\t\tclose(req.done)\n\t\t}\n\n\t\tdrain := func() {\n\t\t\tfor {\n\t\t\t\tselect {\n\t\t\t\tcase msg, ok := <-WALMessages:\n\t\t\t\t\tif !ok {\n\t\t\t\t\t\treturn\n\t\t\t\t\t}\n\t\t\t\t\tprocessMsg(msg)\n\t\t\t\tcase req := <-walRotateCh:\n\t\t\t\t\tprocessRotate(req)\n\t\t\t\tdefault:\n\t\t\t\t\t// Flush all buffered writers after draining remaining messages.\n\t\t\t\t\tfor _, ws := range hostFiles {\n\t\t\t\t\t\tif ws.f != nil {\n\t\t\t\t\t\t\tws.w.Flush()\n\t\t\t\t\t\t}\n\t\t\t\t\t}\n\t\t\t\t\treturn\n\t\t\t\t}\n\t\t\t}\n\t\t}\n\n\t\tfor {\n\t\t\tselect {\n\t\t\tcase <-ctx.Done():\n\t\t\t\tdrain()\n\t\t\t\treturn\n\t\t\tcase msg, ok := <-WALMessages:\n\t\t\t\tif !ok {\n\t\t\t\t\treturn\n\t\t\t\t}\n\t\t\t\tprocessMsg(msg)\n\t\t\tcase req := <-walRotateCh:\n\t\t\t\tprocessRotate(req)\n\t\t\t}\n\t\t}\n\t})\n}\n\n// RotateWALFiles sends rotation requests for the given host directories\n// and blocks until all rotations complete.\nfunc RotateWALFiles(hostDirs []string) {\n\tdones := make([]chan struct{}, len(hostDirs))\n\tfor i, dir := range hostDirs {\n\t\tdones[i] = make(chan struct{})\n\t\twalRotateCh <- walRotateReq{hostDir: dir, done: dones[i]}\n\t}\n\tfor _, done := range dones {\n\t\t<-done\n\t}\n}\n\n// RotateWALFiles sends rotation requests for the given host directories\n// and blocks until all rotations complete.\nfunc RotateWALFilesAfterShutdown(hostDirs []string) {\n\tfor _, dir := range hostDirs {\n\t\twalPath := path.Join(dir, \"current.wal\")\n\t\tif err := os.Remove(walPath); err != nil && !os.IsNotExist(err) {\n\t\t\tcclog.Errorf(\"[METRICSTORE]> WAL: remove %s: %v\", walPath, err)\n\t\t}\n\t}\n}\n\n// buildWALPayload encodes a WALMessage into a binary payload (without magic/length/CRC).\nfunc buildWALPayload(msg *WALMessage) []byte {\n\tsize := 8 + 2 + len(msg.MetricName) + 1 + 4\n\tfor _, s := range msg.Selector {\n\t\tsize += 1 + len(s)\n\t}\n\n\tbuf := make([]byte, 0, size)\n\n\t// Timestamp (8 bytes, little-endian int64)\n\tvar ts [8]byte\n\tbinary.LittleEndian.PutUint64(ts[:], uint64(msg.Timestamp))\n\tbuf = append(buf, ts[:]...)\n\n\t// Metric name (2-byte length prefix + bytes)\n\tvar mLen [2]byte\n\tbinary.LittleEndian.PutUint16(mLen[:], uint16(len(msg.MetricName)))\n\tbuf = append(buf, mLen[:]...)\n\tbuf = append(buf, msg.MetricName...)\n\n\t// Selector count (1 byte)\n\tbuf = append(buf, byte(len(msg.Selector)))\n\n\t// Selectors (1-byte length prefix + bytes each)\n\tfor _, sel := range msg.Selector {\n\t\tbuf = append(buf, byte(len(sel)))\n\t\tbuf = append(buf, sel...)\n\t}\n\n\t// Value (4 bytes, float32 bit representation)\n\tvar val [4]byte\n\tbinary.LittleEndian.PutUint32(val[:], math.Float32bits(float32(msg.Value)))\n\tbuf = append(buf, val[:]...)\n\n\treturn buf\n}\n\n// writeWALRecord appends a binary WAL record to the writer.\n// Format: [4B magic][4B payload_len][payload][4B CRC32]\nfunc writeWALRecord(w io.Writer, msg *WALMessage) error {\n\tpayload := buildWALPayload(msg)\n\tcrc := crc32.ChecksumIEEE(payload)\n\n\trecord := make([]byte, 0, 4+4+len(payload)+4)\n\n\tvar magic [4]byte\n\tbinary.LittleEndian.PutUint32(magic[:], walRecordMagic)\n\trecord = append(record, magic[:]...)\n\n\tvar pLen [4]byte\n\tbinary.LittleEndian.PutUint32(pLen[:], uint32(len(payload)))\n\trecord = append(record, pLen[:]...)\n\n\trecord = append(record, payload...)\n\n\tvar crcBytes [4]byte\n\tbinary.LittleEndian.PutUint32(crcBytes[:], crc)\n\trecord = append(record, crcBytes[:]...)\n\n\t_, err := w.Write(record)\n\treturn err\n}\n\n// readWALRecord reads one WAL record from the reader.\n// Returns (nil, nil) on clean EOF. Returns error on data corruption.\n// A CRC mismatch indicates a truncated trailing record (expected on crash).\nfunc readWALRecord(r io.Reader) (*WALMessage, error) {\n\tvar magic uint32\n\tif err := binary.Read(r, binary.LittleEndian, &magic); err != nil {\n\t\tif err == io.EOF {\n\t\t\treturn nil, nil // Clean EOF\n\t\t}\n\t\treturn nil, fmt.Errorf(\"read record magic: %w\", err)\n\t}\n\n\tif magic != walRecordMagic {\n\t\treturn nil, fmt.Errorf(\"invalid record magic 0x%08X (expected 0x%08X)\", magic, walRecordMagic)\n\t}\n\n\tvar payloadLen uint32\n\tif err := binary.Read(r, binary.LittleEndian, &payloadLen); err != nil {\n\t\treturn nil, fmt.Errorf(\"read payload length: %w\", err)\n\t}\n\n\tif payloadLen > 1<<20 { // 1 MB sanity limit\n\t\treturn nil, fmt.Errorf(\"record payload too large: %d bytes\", payloadLen)\n\t}\n\n\tpayload := make([]byte, payloadLen)\n\tif _, err := io.ReadFull(r, payload); err != nil {\n\t\treturn nil, fmt.Errorf(\"read payload: %w\", err)\n\t}\n\n\tvar storedCRC uint32\n\tif err := binary.Read(r, binary.LittleEndian, &storedCRC); err != nil {\n\t\treturn nil, fmt.Errorf(\"read CRC: %w\", err)\n\t}\n\n\tif crc32.ChecksumIEEE(payload) != storedCRC {\n\t\treturn nil, fmt.Errorf(\"CRC mismatch (truncated write or corruption)\")\n\t}\n\n\treturn parseWALPayload(payload)\n}\n\n// parseWALPayload decodes a binary payload into a WALMessage.\nfunc parseWALPayload(payload []byte) (*WALMessage, error) {\n\tif len(payload) < 8+2+1+4 {\n\t\treturn nil, fmt.Errorf(\"payload too short: %d bytes\", len(payload))\n\t}\n\n\toffset := 0\n\n\t// Timestamp (8 bytes)\n\tts := int64(binary.LittleEndian.Uint64(payload[offset : offset+8]))\n\toffset += 8\n\n\t// Metric name (2-byte length + bytes)\n\tif offset+2 > len(payload) {\n\t\treturn nil, fmt.Errorf(\"metric name length overflows payload\")\n\t}\n\tmLen := int(binary.LittleEndian.Uint16(payload[offset : offset+2]))\n\toffset += 2\n\n\tif offset+mLen > len(payload) {\n\t\treturn nil, fmt.Errorf(\"metric name overflows payload\")\n\t}\n\tmetricName := string(payload[offset : offset+mLen])\n\toffset += mLen\n\n\t// Selector count (1 byte)\n\tif offset >= len(payload) {\n\t\treturn nil, fmt.Errorf(\"selector count overflows payload\")\n\t}\n\tselCount := int(payload[offset])\n\toffset++\n\n\tselectors := make([]string, selCount)\n\tfor i := range selCount {\n\t\tif offset >= len(payload) {\n\t\t\treturn nil, fmt.Errorf(\"selector[%d] length overflows payload\", i)\n\t\t}\n\t\tsLen := int(payload[offset])\n\t\toffset++\n\n\t\tif offset+sLen > len(payload) {\n\t\t\treturn nil, fmt.Errorf(\"selector[%d] data overflows payload\", i)\n\t\t}\n\t\tselectors[i] = string(payload[offset : offset+sLen])\n\t\toffset += sLen\n\t}\n\n\t// Value (4 bytes, float32 bits)\n\tif offset+4 > len(payload) {\n\t\treturn nil, fmt.Errorf(\"value overflows payload\")\n\t}\n\tbits := binary.LittleEndian.Uint32(payload[offset : offset+4])\n\tvalue := schema.Float(math.Float32frombits(bits))\n\n\treturn &WALMessage{\n\t\tMetricName: metricName,\n\t\tTimestamp: ts,\n\t\tSelector: selectors,\n\t\tValue: value,\n\t}, nil\n}\n\n// loadWALFile reads a WAL file and replays all valid records into the Level tree.\n// l is the host-level node. Corrupt or partial trailing records are silently skipped\n// (expected on crash). Records older than 'from' are skipped.\nfunc (l *Level) loadWALFile(m *MemoryStore, f *os.File, from int64) error {\n\tbr := bufio.NewReader(f)\n\n\t// Verify file header magic.\n\tvar fileMagic uint32\n\tif err := binary.Read(br, binary.LittleEndian, &fileMagic); err != nil {\n\t\tif err == io.EOF {\n\t\t\treturn nil // Empty file, no data\n\t\t}\n\t\treturn fmt.Errorf(\"[METRICSTORE]> WAL: read file header: %w\", err)\n\t}\n\n\tif fileMagic != walFileMagic {\n\t\treturn fmt.Errorf(\"[METRICSTORE]> WAL: invalid file magic 0x%08X (expected 0x%08X)\", fileMagic, walFileMagic)\n\t}\n\n\t// Cache level lookups to avoid repeated tree traversal.\n\tlvlCache := make(map[string]*Level)\n\n\tfor {\n\t\tmsg, err := readWALRecord(br)\n\t\tif err != nil {\n\t\t\t// Truncated trailing record is expected after a crash; stop replaying.\n\t\t\tcclog.Debugf(\"[METRICSTORE]> WAL: stopping replay at corrupted/partial record: %v\", err)\n\t\t\tbreak\n\t\t}\n\t\tif msg == nil {\n\t\t\tbreak // Clean EOF\n\t\t}\n\n\t\tif msg.Timestamp < from {\n\t\t\tcontinue // Older than retention window\n\t\t}\n\n\t\tminfo, ok := m.Metrics[msg.MetricName]\n\t\tif !ok {\n\t\t\tcontinue // Unknown metric (config may have changed)\n\t\t}\n\n\t\t// Cache key is the null-separated selector path.\n\t\tcacheKey := joinSelector(msg.Selector)\n\t\tlvl, ok := lvlCache[cacheKey]\n\t\tif !ok {\n\t\t\tlvl = l.findLevelOrCreate(msg.Selector, len(m.Metrics))\n\t\t\tlvlCache[cacheKey] = lvl\n\t\t}\n\n\t\t// Write directly to the buffer, same as WriteToLevel but without the\n\t\t// global level lookup (we already have the right level).\n\t\tlvl.lock.Lock()\n\t\tb := lvl.metrics[minfo.offset]\n\t\tif b == nil {\n\t\t\tb = newBuffer(msg.Timestamp, minfo.Frequency)\n\t\t\tlvl.metrics[minfo.offset] = b\n\t\t}\n\t\tnb, writeErr := b.write(msg.Timestamp, msg.Value)\n\t\tif writeErr == nil && b != nb {\n\t\t\tlvl.metrics[minfo.offset] = nb\n\t\t}\n\t\t// Ignore write errors for timestamps before buffer start (can happen when\n\t\t// replaying WAL entries that predate a loaded snapshot's start time).\n\t\tlvl.lock.Unlock()\n\t}\n\n\treturn nil\n}\n\n// joinSelector builds a cache key from a selector slice using null bytes as separators.\nfunc joinSelector(sel []string) string {\n\tif len(sel) == 0 {\n\t\treturn \"\"\n\t}\n\tvar result strings.Builder\n\tresult.WriteString(sel[0])\n\tfor i := 1; i < len(sel); i++ {\n\t\tresult.WriteString(\"\\x00\" + sel[i])\n\t}\n\treturn result.String()\n}\n\n// ToCheckpointWAL writes binary snapshot files for all hosts in parallel.\n// Returns the number of files written, the list of host directories that were\n// successfully checkpointed (for WAL rotation), and any errors.\nfunc (m *MemoryStore) ToCheckpointWAL(dir string, from, to int64) (int, []string, error) {\n\t// Collect all cluster/host pairs.\n\tm.root.lock.RLock()\n\ttotalHosts := 0\n\tfor _, l1 := range m.root.children {\n\t\tl1.lock.RLock()\n\t\ttotalHosts += len(l1.children)\n\t\tl1.lock.RUnlock()\n\t}\n\tm.root.lock.RUnlock()\n\n\tlevels := make([]*Level, 0, totalHosts)\n\tselectors := make([][]string, 0, totalHosts)\n\n\tm.root.lock.RLock()\n\tfor sel1, l1 := range m.root.children {\n\t\tl1.lock.RLock()\n\t\tfor sel2, l2 := range l1.children {\n\t\t\tlevels = append(levels, l2)\n\t\t\tselectors = append(selectors, []string{sel1, sel2})\n\t\t}\n\t\tl1.lock.RUnlock()\n\t}\n\tm.root.lock.RUnlock()\n\n\ttype workItem struct {\n\t\tlevel *Level\n\t\thostDir string\n\t\tselector []string\n\t}\n\n\tn, errs := int32(0), int32(0)\n\tvar successDirs []string\n\tvar successMu sync.Mutex\n\n\tvar wg sync.WaitGroup\n\twg.Add(Keys.NumWorkers)\n\twork := make(chan workItem, Keys.NumWorkers*2)\n\n\tfor range Keys.NumWorkers {\n\t\tgo func() {\n\t\t\tdefer wg.Done()\n\t\t\tfor wi := range work {\n\t\t\t\terr := wi.level.toCheckpointBinary(wi.hostDir, from, to, m)\n\t\t\t\tif err != nil {\n\t\t\t\t\tif err == ErrNoNewArchiveData {\n\t\t\t\t\t\tcontinue\n\t\t\t\t\t}\n\t\t\t\t\tcclog.Errorf(\"[METRICSTORE]> binary checkpoint error for %s: %v\", wi.hostDir, err)\n\t\t\t\t\tatomic.AddInt32(&errs, 1)\n\t\t\t\t} else {\n\t\t\t\t\tatomic.AddInt32(&n, 1)\n\t\t\t\t\tsuccessMu.Lock()\n\t\t\t\t\tsuccessDirs = append(successDirs, wi.hostDir)\n\t\t\t\t\tsuccessMu.Unlock()\n\t\t\t\t}\n\t\t\t}\n\t\t}()\n\t}\n\n\tfor i := range levels {\n\t\thostDir := path.Join(dir, path.Join(selectors[i]...))\n\t\twork <- workItem{\n\t\t\tlevel: levels[i],\n\t\t\thostDir: hostDir,\n\t\t\tselector: selectors[i],\n\t\t}\n\t}\n\tclose(work)\n\twg.Wait()\n\n\tif errs > 0 {\n\t\treturn int(n), successDirs, fmt.Errorf(\"[METRICSTORE]> %d errors during binary checkpoint (%d successes)\", errs, n)\n\t}\n\treturn int(n), successDirs, nil\n}\n\n// toCheckpointBinary writes a binary snapshot file for a single host-level node.\n// Uses atomic rename (write to .tmp then rename) to avoid partial reads on crash.\nfunc (l *Level) toCheckpointBinary(dir string, from, to int64, m *MemoryStore) error {\n\tcf, err := l.toCheckpointFile(from, to, m)\n\tif err != nil {\n\t\treturn err\n\t}\n\tif cf == nil {\n\t\treturn ErrNoNewArchiveData\n\t}\n\n\tif err := os.MkdirAll(dir, CheckpointDirPerms); err != nil {\n\t\treturn fmt.Errorf(\"mkdir %s: %w\", dir, err)\n\t}\n\n\t// Write to a temp file first, then rename (atomic on POSIX).\n\ttmpPath := path.Join(dir, fmt.Sprintf(\"%d.bin.tmp\", from))\n\tfinalPath := path.Join(dir, fmt.Sprintf(\"%d.bin\", from))\n\n\tf, err := os.OpenFile(tmpPath, os.O_CREATE|os.O_WRONLY|os.O_TRUNC, CheckpointFilePerms)\n\tif err != nil {\n\t\treturn fmt.Errorf(\"open binary snapshot %s: %w\", tmpPath, err)\n\t}\n\n\tbw := bufio.NewWriter(f)\n\tif err := writeBinarySnapshotFile(bw, cf); err != nil {\n\t\tf.Close()\n\t\tos.Remove(tmpPath)\n\t\treturn fmt.Errorf(\"write binary snapshot: %w\", err)\n\t}\n\tif err := bw.Flush(); err != nil {\n\t\tf.Close()\n\t\tos.Remove(tmpPath)\n\t\treturn err\n\t}\n\tf.Close()\n\n\treturn os.Rename(tmpPath, finalPath)\n}\n\n// writeBinarySnapshotFile writes the binary snapshot file header and level tree.\nfunc writeBinarySnapshotFile(w io.Writer, cf *CheckpointFile) error {\n\tif err := binary.Write(w, binary.LittleEndian, snapFileMagic); err != nil {\n\t\treturn err\n\t}\n\tif err := binary.Write(w, binary.LittleEndian, cf.From); err != nil {\n\t\treturn err\n\t}\n\tif err := binary.Write(w, binary.LittleEndian, cf.To); err != nil {\n\t\treturn err\n\t}\n\treturn writeBinaryLevel(w, cf)\n}\n\n// writeBinaryLevel recursively writes a CheckpointFile level in binary format.\nfunc writeBinaryLevel(w io.Writer, cf *CheckpointFile) error {\n\tif err := binary.Write(w, binary.LittleEndian, uint32(len(cf.Metrics))); err != nil {\n\t\treturn err\n\t}\n\n\tfor name, metric := range cf.Metrics {\n\t\tif err := writeString16(w, name); err != nil {\n\t\t\treturn err\n\t\t}\n\t\tif err := binary.Write(w, binary.LittleEndian, metric.Frequency); err != nil {\n\t\t\treturn err\n\t\t}\n\t\tif err := binary.Write(w, binary.LittleEndian, metric.Start); err != nil {\n\t\t\treturn err\n\t\t}\n\t\tif err := binary.Write(w, binary.LittleEndian, uint32(len(metric.Data))); err != nil {\n\t\t\treturn err\n\t\t}\n\t\tfor _, v := range metric.Data {\n\t\t\tif err := binary.Write(w, binary.LittleEndian, math.Float32bits(float32(v))); err != nil {\n\t\t\t\treturn err\n\t\t\t}\n\t\t}\n\t}\n\n\tif err := binary.Write(w, binary.LittleEndian, uint32(len(cf.Children))); err != nil {\n\t\treturn err\n\t}\n\n\tfor name, child := range cf.Children {\n\t\tif err := writeString16(w, name); err != nil {\n\t\t\treturn err\n\t\t}\n\t\tif err := writeBinaryLevel(w, child); err != nil {\n\t\t\treturn err\n\t\t}\n\t}\n\n\treturn nil\n}\n\n// writeString16 writes a 2-byte length-prefixed string to w.\nfunc writeString16(w io.Writer, s string) error {\n\tif err := binary.Write(w, binary.LittleEndian, uint16(len(s))); err != nil {\n\t\treturn err\n\t}\n\t_, err := io.WriteString(w, s)\n\treturn err\n}\n\n// loadBinaryFile reads a binary snapshot file and loads data into the Level tree.\n// The retention check (from) is applied to the file's 'to' timestamp.\nfunc (l *Level) loadBinaryFile(m *MemoryStore, f *os.File, from int64) error {\n\tbr := bufio.NewReader(f)\n\n\tvar magic uint32\n\tif err := binary.Read(br, binary.LittleEndian, &magic); err != nil {\n\t\treturn fmt.Errorf(\"[METRICSTORE]> binary snapshot: read magic: %w\", err)\n\t}\n\tif magic != snapFileMagic {\n\t\treturn fmt.Errorf(\"[METRICSTORE]> binary snapshot: invalid magic 0x%08X (expected 0x%08X)\", magic, snapFileMagic)\n\t}\n\n\tvar fileFrom, fileTo int64\n\tif err := binary.Read(br, binary.LittleEndian, &fileFrom); err != nil {\n\t\treturn fmt.Errorf(\"[METRICSTORE]> binary snapshot: read from: %w\", err)\n\t}\n\tif err := binary.Read(br, binary.LittleEndian, &fileTo); err != nil {\n\t\treturn fmt.Errorf(\"[METRICSTORE]> binary snapshot: read to: %w\", err)\n\t}\n\n\tif fileTo != 0 && fileTo < from {\n\t\treturn nil // File is older than retention window, skip it\n\t}\n\n\tcf, err := readBinaryLevel(br)\n\tif err != nil {\n\t\treturn fmt.Errorf(\"[METRICSTORE]> binary snapshot: read level tree: %w\", err)\n\t}\n\tcf.From = fileFrom\n\tcf.To = fileTo\n\n\treturn l.loadFile(cf, m)\n}\n\n// readBinaryLevel recursively reads a level from the binary snapshot format.\nfunc readBinaryLevel(r io.Reader) (*CheckpointFile, error) {\n\tcf := &CheckpointFile{\n\t\tMetrics: make(map[string]*CheckpointMetrics),\n\t\tChildren: make(map[string]*CheckpointFile),\n\t}\n\n\tvar numMetrics uint32\n\tif err := binary.Read(r, binary.LittleEndian, &numMetrics); err != nil {\n\t\treturn nil, fmt.Errorf(\"read num_metrics: %w\", err)\n\t}\n\n\tfor range numMetrics {\n\t\tname, err := readString16(r)\n\t\tif err != nil {\n\t\t\treturn nil, fmt.Errorf(\"read metric name: %w\", err)\n\t\t}\n\n\t\tvar freq, start int64\n\t\tif err := binary.Read(r, binary.LittleEndian, &freq); err != nil {\n\t\t\treturn nil, fmt.Errorf(\"read frequency for %s: %w\", name, err)\n\t\t}\n\t\tif err := binary.Read(r, binary.LittleEndian, &start); err != nil {\n\t\t\treturn nil, fmt.Errorf(\"read start for %s: %w\", name, err)\n\t\t}\n\n\t\tvar numValues uint32\n\t\tif err := binary.Read(r, binary.LittleEndian, &numValues); err != nil {\n\t\t\treturn nil, fmt.Errorf(\"read num_values for %s: %w\", name, err)\n\t\t}\n\n\t\tdata := make([]schema.Float, numValues)\n\t\tfor i := range numValues {\n\t\t\tvar bits uint32\n\t\t\tif err := binary.Read(r, binary.LittleEndian, &bits); err != nil {\n\t\t\t\treturn nil, fmt.Errorf(\"read value[%d] for %s: %w\", i, name, err)\n\t\t\t}\n\t\t\tdata[i] = schema.Float(math.Float32frombits(bits))\n\t\t}\n\n\t\tcf.Metrics[name] = &CheckpointMetrics{\n\t\t\tFrequency: freq,\n\t\t\tStart: start,\n\t\t\tData: data,\n\t\t}\n\t}\n\n\tvar numChildren uint32\n\tif err := binary.Read(r, binary.LittleEndian, &numChildren); err != nil {\n\t\treturn nil, fmt.Errorf(\"read num_children: %w\", err)\n\t}\n\n\tfor range numChildren {\n\t\tchildName, err := readString16(r)\n\t\tif err != nil {\n\t\t\treturn nil, fmt.Errorf(\"read child name: %w\", err)\n\t\t}\n\n\t\tchild, err := readBinaryLevel(r)\n\t\tif err != nil {\n\t\t\treturn nil, fmt.Errorf(\"read child %s: %w\", childName, err)\n\t\t}\n\t\tcf.Children[childName] = child\n\t}\n\n\treturn cf, nil\n}\n\n// readString16 reads a 2-byte length-prefixed string from r.\nfunc readString16(r io.Reader) (string, error) {\n\tvar sLen uint16\n\tif err := binary.Read(r, binary.LittleEndian, &sLen); err != nil {\n\t\treturn \"\", err\n\t}\n\tbuf := make([]byte, sLen)\n\tif _, err := io.ReadFull(r, buf); err != nil {\n\t\treturn \"\", err\n\t}\n\treturn string(buf), nil\n}\n","structuredPatch":[{"oldStart":226,"oldLines":6,"newStart":226,"newLines":28,"lines":[" return"," }"," processMsg(msg)","+","+ // Drain up to 256 more messages without blocking to batch writes.","+ for range 256 {","+ select {","+ case msg, ok := <-WALMessages:","+ if !ok {","+ return","+ }","+ processMsg(msg)","+ case req := <-walRotateCh:","+ processRotate(req)","+ default:","+ goto flushed","+ }","+ }","+ flushed:","+ // Flush all buffered writers after processing the batch.","+ for _, ws := range hostFiles {","+ if ws.f != nil {","+ ws.w.Flush()","+ }","+ }"," case req := <-walRotateCh:"," processRotate(req)"," }"]}],"userModified":false,"replaceAll":false},"sourceToolAssistantUUID":"dc2282bb-a59e-4924-8bd9-8ec3771a318f","userType":"external","entrypoint":"cli","cwd":"/Users/jan/prg/ClusterCockpit/cc-backend","sessionId":"5eb20a94-f8df-4979-a0ae-2aa99bfad884","version":"2.1.78","gitBranch":"hotfix","slug":"bright-wandering-flurry"} +{"parentUuid":"0bb50aad-bae3-4297-bb66-e7f853d8063f","isSidechain":false,"message":{"model":"claude-opus-4-6","id":"msg_01KCZSX1nTM8jgK9ECiYRM1i","type":"message","role":"assistant","content":[{"type":"text","text":"Now let me verify it compiles and tests 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+{"parentUuid":"d584cb3c-728b-4f6c-83c9-f9f5e3c28cb6","isSidechain":false,"message":{"model":"claude-opus-4-6","id":"msg_014C3W3gjCbq2LFgAoX29pz1","type":"message","role":"assistant","content":[{"type":"text","text":"All compiles and tests pass. Here's a summary of the four changes:\n\n### Changes made\n\n1. **`metricstore.go:187`** — Changed `ReceiveNats(ms, 1, ctx)` to `ReceiveNats(ms, Keys.NumWorkers, ctx)`. This parallelizes `DecodeLine()` across multiple goroutines instead of running it inline in the NATS callback.\n\n2. **`lineprotocol.go:56`** — Increased the `msgs` channel buffer from `workers*2` to `max(workers*256, 8192)`. This decouples the NATS callback from the decode workers with a much larger buffer.\n\n3. **`lineprotocol.go:353-368`** — Made the WAL channel send non-blocking with `select/default`. Dropped messages are counted via an atomic counter and logged every 10,000 drops. Since the in-memory write succeeds first, dropped WAL messages are recovered by the next binary snapshot.\n\n4. **`walCheckpoint.go:219-247`** — Added batch drain loop in `WALStaging`: after processing one message, it drains up to 256 more without blocking, then flushes all buffered writers. This reduces `select` overhead and batches I/O.\n\n5. **`walCheckpoint.go:85`** — Increased WAL channel buffer from 4,096 to 65,536 for more burst headroom."}],"stop_reason":"end_turn","stop_sequence":null,"usage":{"input_tokens":1,"cache_creation_input_tokens":143,"cache_read_input_tokens":53472,"output_tokens":342,"server_tool_use":{"web_search_requests":0,"web_fetch_requests":0},"service_tier":"standard","cache_creation":{"ephemeral_1h_input_tokens":143,"ephemeral_5m_input_tokens":0},"inference_geo":"","iterations":[],"speed":"standard"}},"requestId":"req_011CZ9yBbbjs9fuLtVTfpLLM","type":"assistant","uuid":"d74329ff-67f4-443c-bc69-bcc41feeb8e5","timestamp":"2026-03-18T05:10:20.370Z","userType":"external","entrypoint":"cli","cwd":"/Users/jan/prg/ClusterCockpit/cc-backend","sessionId":"5eb20a94-f8df-4979-a0ae-2aa99bfad884","version":"2.1.78","gitBranch":"hotfix","slug":"bright-wandering-flurry"} 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+{"type":"file-history-snapshot","messageId":"55cac468-7db6-44ab-a740-f6de61080fce","snapshot":{"messageId":"55cac468-7db6-44ab-a740-f6de61080fce","trackedFileBackups":{"pkg/metricstore/metricstore.go":{"backupFileName":"9d6c8b589b687438@v2","version":2,"backupTime":"2026-03-18T05:11:40.599Z"},"pkg/metricstore/lineprotocol.go":{"backupFileName":"90dc6599471442f6@v2","version":2,"backupTime":"2026-03-18T05:11:40.599Z"},"pkg/metricstore/walCheckpoint.go":{"backupFileName":"f5b5b4bac0274f50@v2","version":2,"backupTime":"2026-03-18T05:11:40.599Z"}},"timestamp":"2026-03-18T05:11:40.598Z"},"isSnapshotUpdate":false} +{"parentUuid":"67f623a1-88a6-4b40-92c2-9c9b93d8d0ed","isSidechain":false,"promptId":"7fcb2439-dc17-41be-9fe8-b2528689e6af","type":"user","message":{"role":"user","content":"Does a similar problem occur on the metricstore REST API path?"},"uuid":"55cac468-7db6-44ab-a740-f6de61080fce","timestamp":"2026-03-18T05:11:39.920Z","permissionMode":"acceptEdits","userType":"external","entrypoint":"cli","cwd":"/Users/jan/prg/ClusterCockpit/cc-backend","sessionId":"5eb20a94-f8df-4979-a0ae-2aa99bfad884","version":"2.1.78","gitBranch":"hotfix","slug":"bright-wandering-flurry"} 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make(map[string]metricstore.HealthCheckResult)\ninternal/api/api_test.go:29:\t\"github.com/ClusterCockpit/cc-backend/pkg/metricstore\"\ninternal/api/api_test.go:153:\tmetricstore.MetricStoreHandle = &metricstore.InternalMetricStore{}\ninternal/api/api_test.go:169:\t// metricstore initialization removed - it's initialized via callback in tests\ninternal/api/api_test.go:215:\tmetricstore.TestLoadDataCallback = func(job *schema.Job, metrics []string, scopes []schema.MetricScope, ctx context.Context, resolution int) (schema.JobData, error) {\ninternal/api/api_test.go:516:\tmetricstore.TestLoadDataCallback = func(job *schema.Job, metrics []string, scopes []schema.MetricScope, ctx context.Context, resolution int) (schema.JobData, error) {\ninternal/api/metricstore.go:17:\t\"github.com/ClusterCockpit/cc-backend/pkg/metricstore\"\ninternal/api/metricstore.go:60:\tms := metricstore.GetMemoryStore()\ninternal/api/metricstore.go:100:\tms := 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4→// license that can be found in the LICENSE file.\n 5→\n 6→package api\n 7→\n 8→import (\n 9→\t\"bufio\"\n 10→\t\"encoding/json\"\n 11→\t\"errors\"\n 12→\t\"fmt\"\n 13→\t\"net/http\"\n 14→\t\"strconv\"\n 15→\t\"strings\"\n 16→\n 17→\t\"github.com/ClusterCockpit/cc-backend/pkg/metricstore\"\n 18→\tcclog \"github.com/ClusterCockpit/cc-lib/v2/ccLogger\"\n 19→\n 20→\t\"github.com/ClusterCockpit/cc-line-protocol/v2/lineprotocol\"\n 21→)\n 22→\n 23→// handleFree godoc\n 24→// @summary\n 25→// @tags free\n 26→// @description This endpoint allows the users to free the Buffers from the\n 27→// metric store. This endpoint offers the users to remove then systematically\n 28→// and also allows then to prune the data under node, if they do not want to\n 29→// remove the whole node.\n 30→// @produce json\n 31→// @param to query string false \"up to timestamp\"\n 32→// @success 200 {string} string \"ok\"\n 33→// @failure 400 {object} api.ErrorResponse \"Bad Request\"\n 34→// @failure 401 {object} api.ErrorResponse \"Unauthorized\"\n 35→// @failure 403 {object} api.ErrorResponse \"Forbidden\"\n 36→// @failure 500 {object} api.ErrorResponse \"Internal Server Error\"\n 37→// @security ApiKeyAuth\n 38→// @router /free/ [post]\n 39→func freeMetrics(rw http.ResponseWriter, r *http.Request) {\n 40→\trawTo := r.URL.Query().Get(\"to\")\n 41→\tif rawTo == \"\" {\n 42→\t\thandleError(errors.New(\"'to' is a required query parameter\"), http.StatusBadRequest, rw)\n 43→\t\treturn\n 44→\t}\n 45→\n 46→\tto, err := strconv.ParseInt(rawTo, 10, 64)\n 47→\tif err != nil {\n 48→\t\thandleError(err, http.StatusInternalServerError, rw)\n 49→\t\treturn\n 50→\t}\n 51→\n 52→\tbodyDec := json.NewDecoder(r.Body)\n 53→\tvar selectors [][]string\n 54→\terr = bodyDec.Decode(&selectors)\n 55→\tif err != nil {\n 56→\t\thttp.Error(rw, err.Error(), http.StatusBadRequest)\n 57→\t\treturn\n 58→\t}\n 59→\n 60→\tms := metricstore.GetMemoryStore()\n 61→\tn := 0\n 62→\tfor _, sel := range selectors {\n 63→\t\tbn, err := ms.Free(sel, to)\n 64→\t\tif err != nil {\n 65→\t\t\thandleError(err, http.StatusInternalServerError, rw)\n 66→\t\t\treturn\n 67→\t\t}\n 68→\n 69→\t\tn += bn\n 70→\t}\n 71→\n 72→\trw.WriteHeader(http.StatusOK)\n 73→\tfmt.Fprintf(rw, \"buffers freed: %d\\n\", n)\n 74→}\n 75→\n 76→// handleWrite godoc\n 77→// @summary Receive metrics in InfluxDB line-protocol\n 78→// @tags write\n 79→// @description Write data to the in-memory store in the InfluxDB line-protocol using [this format](https://github.com/ClusterCockpit/cc-specifications/blob/master/metrics/lineprotocol_alternative.md)\n 80→\n 81→// @accept plain\n 82→// @produce json\n 83→// @param cluster query string false \"If the lines in the body do not have a cluster tag, use this value instead.\"\n 84→// @success 200 {string} string \"ok\"\n 85→// @failure 400 {object} api.ErrorResponse \"Bad Request\"\n 86→// @failure 401 {object} api.ErrorResponse \"Unauthorized\"\n 87→// @failure 403 {object} api.ErrorResponse \"Forbidden\"\n 88→// @failure 500 {object} api.ErrorResponse \"Internal Server Error\"\n 89→// @security ApiKeyAuth\n 90→// @router /write/ [post]\n 91→func writeMetrics(rw http.ResponseWriter, r *http.Request) {\n 92→\trw.Header().Add(\"Content-Type\", \"application/json\")\n 93→\n 94→\t// Extract the \"cluster\" query parameter without allocating a url.Values map.\n 95→\tcluster := queryParam(r.URL.RawQuery, \"cluster\")\n 96→\n 97→\t// Stream directly from the request body instead of copying it into a\n 98→\t// temporary buffer via io.ReadAll. The line-protocol decoder supports\n 99→\t// io.Reader natively, so this avoids the largest heap allocation.\n 100→\tms := metricstore.GetMemoryStore()\n 101→\tdec := lineprotocol.NewDecoder(r.Body)\n 102→\tif err := metricstore.DecodeLine(dec, ms, cluster); err != nil {\n 103→\t\tcclog.Errorf(\"/api/write error: %s\", err.Error())\n 104→\t\thandleError(err, http.StatusBadRequest, rw)\n 105→\t\treturn\n 106→\t}\n 107→\trw.WriteHeader(http.StatusOK)\n 108→}\n 109→\n 110→// queryParam extracts a single query-parameter value from a raw query string\n 111→// without allocating a url.Values map. Returns \"\" if the key is not present.\n 112→func queryParam(raw, key string) string {\n 113→\tfor raw != \"\" {\n 114→\t\tvar kv string\n 115→\t\tkv, raw, _ = strings.Cut(raw, \"&\")\n 116→\t\tk, v, _ := strings.Cut(kv, \"=\")\n 117→\t\tif k == key {\n 118→\t\t\treturn v\n 119→\t\t}\n 120→\t}\n 121→\treturn \"\"\n 122→}\n 123→\n 124→// handleDebug godoc\n 125→// @summary Debug endpoint\n 126→// @tags debug\n 127→// @description This endpoint allows the users to print the content of\n 128→// nodes/clusters/metrics to review the state of the data.\n 129→// @produce json\n 130→// @param selector query string false \"Selector\"\n 131→// @success 200 {string} string \"Debug dump\"\n 132→// @failure 400 {object} api.ErrorResponse \"Bad Request\"\n 133→// @failure 401 {object} api.ErrorResponse \"Unauthorized\"\n 134→// @failure 403 {object} api.ErrorResponse \"Forbidden\"\n 135→// @failure 500 {object} api.ErrorResponse \"Internal Server Error\"\n 136→// @security ApiKeyAuth\n 137→// @router /debug/ [post]\n 138→func debugMetrics(rw http.ResponseWriter, r *http.Request) {\n 139→\traw := r.URL.Query().Get(\"selector\")\n 140→\trw.Header().Add(\"Content-Type\", \"application/json\")\n 141→\tselector := []string{}\n 142→\tif len(raw) != 0 {\n 143→\t\tselector = strings.Split(raw, \":\")\n 144→\t}\n 145→\n 146→\tms := metricstore.GetMemoryStore()\n 147→\tif err := ms.DebugDump(bufio.NewWriter(rw), selector); err != nil {\n 148→\t\thandleError(err, http.StatusBadRequest, rw)\n 149→\t\treturn\n 150→\t}\n 151→}\n 152→"}]},"uuid":"39913ac6-6fa1-456c-a38f-a14878579339","timestamp":"2026-03-18T05:11:55.142Z","toolUseResult":{"type":"text","file":{"filePath":"/Users/jan/prg/ClusterCockpit/cc-backend/internal/api/metricstore.go","content":"// Copyright (C) NHR@FAU, University Erlangen-Nuremberg.\n// All rights reserved.\n// Use of this source code is governed by a MIT-style\n// license that can be found in the LICENSE file.\n\npackage api\n\nimport (\n\t\"bufio\"\n\t\"encoding/json\"\n\t\"errors\"\n\t\"fmt\"\n\t\"net/http\"\n\t\"strconv\"\n\t\"strings\"\n\n\t\"github.com/ClusterCockpit/cc-backend/pkg/metricstore\"\n\tcclog \"github.com/ClusterCockpit/cc-lib/v2/ccLogger\"\n\n\t\"github.com/ClusterCockpit/cc-line-protocol/v2/lineprotocol\"\n)\n\n// handleFree godoc\n// @summary\n// @tags free\n// @description This endpoint allows the users to free the Buffers from the\n// metric store. This endpoint offers the users to remove then systematically\n// and also allows then to prune the data under node, if they do not want to\n// remove the whole node.\n// @produce json\n// @param to query string false \"up to timestamp\"\n// @success 200 {string} string \"ok\"\n// @failure 400 {object} api.ErrorResponse \"Bad Request\"\n// @failure 401 {object} api.ErrorResponse \"Unauthorized\"\n// @failure 403 {object} api.ErrorResponse \"Forbidden\"\n// @failure 500 {object} api.ErrorResponse \"Internal Server Error\"\n// @security ApiKeyAuth\n// @router /free/ [post]\nfunc freeMetrics(rw http.ResponseWriter, r *http.Request) {\n\trawTo := r.URL.Query().Get(\"to\")\n\tif rawTo == \"\" {\n\t\thandleError(errors.New(\"'to' is a required query parameter\"), http.StatusBadRequest, rw)\n\t\treturn\n\t}\n\n\tto, err := strconv.ParseInt(rawTo, 10, 64)\n\tif err != nil {\n\t\thandleError(err, http.StatusInternalServerError, rw)\n\t\treturn\n\t}\n\n\tbodyDec := json.NewDecoder(r.Body)\n\tvar selectors [][]string\n\terr = bodyDec.Decode(&selectors)\n\tif err != nil {\n\t\thttp.Error(rw, err.Error(), http.StatusBadRequest)\n\t\treturn\n\t}\n\n\tms := metricstore.GetMemoryStore()\n\tn := 0\n\tfor _, sel := range selectors {\n\t\tbn, err := ms.Free(sel, to)\n\t\tif err != nil {\n\t\t\thandleError(err, http.StatusInternalServerError, rw)\n\t\t\treturn\n\t\t}\n\n\t\tn += bn\n\t}\n\n\trw.WriteHeader(http.StatusOK)\n\tfmt.Fprintf(rw, \"buffers freed: %d\\n\", n)\n}\n\n// handleWrite godoc\n// @summary Receive metrics in InfluxDB line-protocol\n// @tags write\n// @description Write data to the in-memory store in the InfluxDB line-protocol using [this format](https://github.com/ClusterCockpit/cc-specifications/blob/master/metrics/lineprotocol_alternative.md)\n\n// @accept plain\n// @produce json\n// @param cluster query string false \"If the lines in the body do not have a cluster tag, use this value instead.\"\n// @success 200 {string} string \"ok\"\n// @failure 400 {object} api.ErrorResponse \"Bad Request\"\n// @failure 401 {object} api.ErrorResponse \"Unauthorized\"\n// @failure 403 {object} api.ErrorResponse \"Forbidden\"\n// @failure 500 {object} api.ErrorResponse \"Internal Server Error\"\n// @security ApiKeyAuth\n// @router /write/ [post]\nfunc writeMetrics(rw http.ResponseWriter, r *http.Request) {\n\trw.Header().Add(\"Content-Type\", \"application/json\")\n\n\t// Extract the \"cluster\" query parameter without allocating a url.Values map.\n\tcluster := queryParam(r.URL.RawQuery, \"cluster\")\n\n\t// Stream directly from the request body instead of copying it into a\n\t// temporary buffer via io.ReadAll. The line-protocol decoder supports\n\t// io.Reader natively, so this avoids the largest heap allocation.\n\tms := metricstore.GetMemoryStore()\n\tdec := lineprotocol.NewDecoder(r.Body)\n\tif err := metricstore.DecodeLine(dec, ms, cluster); err != nil {\n\t\tcclog.Errorf(\"/api/write error: %s\", err.Error())\n\t\thandleError(err, http.StatusBadRequest, rw)\n\t\treturn\n\t}\n\trw.WriteHeader(http.StatusOK)\n}\n\n// queryParam extracts a single query-parameter value from a raw query string\n// without allocating a url.Values map. Returns \"\" if the key is not present.\nfunc queryParam(raw, key string) string {\n\tfor raw != \"\" {\n\t\tvar kv string\n\t\tkv, raw, _ = strings.Cut(raw, \"&\")\n\t\tk, v, _ := strings.Cut(kv, \"=\")\n\t\tif k == key {\n\t\t\treturn v\n\t\t}\n\t}\n\treturn \"\"\n}\n\n// handleDebug godoc\n// @summary Debug endpoint\n// @tags debug\n// @description This endpoint allows the users to print the content of\n// nodes/clusters/metrics to review the state of the data.\n// @produce json\n// @param selector query string false \"Selector\"\n// @success 200 {string} string \"Debug dump\"\n// @failure 400 {object} api.ErrorResponse \"Bad Request\"\n// @failure 401 {object} api.ErrorResponse \"Unauthorized\"\n// @failure 403 {object} api.ErrorResponse \"Forbidden\"\n// @failure 500 {object} api.ErrorResponse \"Internal Server Error\"\n// @security ApiKeyAuth\n// @router /debug/ [post]\nfunc debugMetrics(rw http.ResponseWriter, r *http.Request) {\n\traw := r.URL.Query().Get(\"selector\")\n\trw.Header().Add(\"Content-Type\", \"application/json\")\n\tselector := []string{}\n\tif len(raw) != 0 {\n\t\tselector = strings.Split(raw, \":\")\n\t}\n\n\tms := metricstore.GetMemoryStore()\n\tif err := ms.DebugDump(bufio.NewWriter(rw), selector); err != nil {\n\t\thandleError(err, http.StatusBadRequest, rw)\n\t\treturn\n\t}\n}\n","numLines":152,"startLine":1,"totalLines":152}},"sourceToolAssistantUUID":"d7c47105-2abd-463a-a30a-1aeb783bd819","userType":"external","entrypoint":"cli","cwd":"/Users/jan/prg/ClusterCockpit/cc-backend","sessionId":"5eb20a94-f8df-4979-a0ae-2aa99bfad884","version":"2.1.78","gitBranch":"hotfix","slug":"bright-wandering-flurry"} +{"parentUuid":"39913ac6-6fa1-456c-a38f-a14878579339","isSidechain":false,"message":{"model":"claude-opus-4-6","id":"msg_01ADY9sKP4TSLAhsNBW6sFso","type":"message","role":"assistant","content":[{"type":"text","text":"No, the REST path does **not** have the same problem.\n\nLooking at `internal/api/metricstore.go:91-108`, the REST `writeMetrics` handler calls `DecodeLine()` synchronously within the HTTP request goroutine. Each HTTP request gets its own goroutine from Go's `net/http` server, so:\n\n1. **No single-threaded bottleneck** — Go's HTTP server spawns a goroutine per request, so multiple concurrent POST requests to `/api/write/` decode in parallel naturally.\n2. **No callback blocking** — There's no subscription callback to block. If `DecodeLine` is slow, it only delays that one HTTP response, which is fine.\n3. **WAL channel send still applies** — The blocking WAL send (now fixed to non-blocking) could have stalled an HTTP handler goroutine, but it wouldn't cause message drops — it would just increase HTTP response latency. With the non-blocking change, this is no longer an issue either.\n\nThe slow consumer problem is specific to the NATS ingestion path because the nats.go client uses a single callback delivery model with an internal pending buffer that drops messages when the callback can't keep up."}],"stop_reason":"end_turn","stop_sequence":null,"usage":{"input_tokens":1,"cache_creation_input_tokens":3517,"cache_read_input_tokens":55932,"output_tokens":275,"server_tool_use":{"web_search_requests":0,"web_fetch_requests":0},"service_tier":"standard","cache_creation":{"ephemeral_1h_input_tokens":3517,"ephemeral_5m_input_tokens":0},"inference_geo":"","iterations":[],"speed":"standard"}},"requestId":"req_011CZ9yKKSsJAHawLsKsZTwc","type":"assistant","uuid":"8c26d9d8-fb78-45b7-a95e-a2acbdbe598e","timestamp":"2026-03-18T05:12:05.537Z","userType":"external","entrypoint":"cli","cwd":"/Users/jan/prg/ClusterCockpit/cc-backend","sessionId":"5eb20a94-f8df-4979-a0ae-2aa99bfad884","version":"2.1.78","gitBranch":"hotfix","slug":"bright-wandering-flurry"} +{"parentUuid":"8c26d9d8-fb78-45b7-a95e-a2acbdbe598e","isSidechain":false,"type":"progress","data":{"type":"hook_progress","hookEvent":"Stop","hookName":"Stop","command":"entire hooks claude-code stop"},"parentToolUseID":"f8cc9fd3-4d19-4382-8e20-6d098d8e437c","toolUseID":"f8cc9fd3-4d19-4382-8e20-6d098d8e437c","timestamp":"2026-03-18T05:12:05.558Z","uuid":"f840c284-a06a-4d08-a70e-8a2ae3313fa9","userType":"external","entrypoint":"cli","cwd":"/Users/jan/prg/ClusterCockpit/cc-backend","sessionId":"5eb20a94-f8df-4979-a0ae-2aa99bfad884","version":"2.1.78","gitBranch":"hotfix","slug":"bright-wandering-flurry"} +{"parentUuid":"f840c284-a06a-4d08-a70e-8a2ae3313fa9","isSidechain":false,"type":"system","subtype":"stop_hook_summary","hookCount":1,"hookInfos":[{"command":"entire hooks claude-code stop","durationMs":572}],"hookErrors":[],"preventedContinuation":false,"stopReason":"","hasOutput":false,"level":"suggestion","timestamp":"2026-03-18T05:12:06.132Z","uuid":"2aef5732-c14e-4f21-9608-c0b2b37f1f81","toolUseID":"f8cc9fd3-4d19-4382-8e20-6d098d8e437c","userType":"external","entrypoint":"cli","cwd":"/Users/jan/prg/ClusterCockpit/cc-backend","sessionId":"5eb20a94-f8df-4979-a0ae-2aa99bfad884","version":"2.1.78","gitBranch":"hotfix","slug":"bright-wandering-flurry"} +{"type":"file-history-snapshot","messageId":"6810ab19-91ba-44a9-b6c0-318d0d32f3b1","snapshot":{"messageId":"6810ab19-91ba-44a9-b6c0-318d0d32f3b1","trackedFileBackups":{"pkg/metricstore/metricstore.go":{"backupFileName":"9d6c8b589b687438@v2","version":2,"backupTime":"2026-03-18T05:11:40.599Z"},"pkg/metricstore/lineprotocol.go":{"backupFileName":"90dc6599471442f6@v2","version":2,"backupTime":"2026-03-18T05:11:40.599Z"},"pkg/metricstore/walCheckpoint.go":{"backupFileName":"f5b5b4bac0274f50@v2","version":2,"backupTime":"2026-03-18T05:11:40.599Z"}},"timestamp":"2026-03-18T05:13:00.244Z"},"isSnapshotUpdate":false} +{"parentUuid":"2aef5732-c14e-4f21-9608-c0b2b37f1f81","isSidechain":false,"promptId":"c62ad23e-e8a3-4176-91e2-f7b7a7cd0185","type":"user","message":{"role":"user","content":"How many os level threads are used in this application? It is currently configurable?"},"uuid":"6810ab19-91ba-44a9-b6c0-318d0d32f3b1","timestamp":"2026-03-18T05:12:59.475Z","permissionMode":"plan","userType":"external","entrypoint":"cli","cwd":"/Users/jan/prg/ClusterCockpit/cc-backend","sessionId":"5eb20a94-f8df-4979-a0ae-2aa99bfad884","version":"2.1.78","gitBranch":"hotfix","slug":"bright-wandering-flurry"} +{"parentUuid":"6810ab19-91ba-44a9-b6c0-318d0d32f3b1","isSidechain":false,"message":{"model":"claude-opus-4-6","id":"msg_01Nw8UrrC9B797Lj6AbS3W8L","type":"message","role":"assistant","content":[{"type":"thinking","thinking":"","signature":"Es8CCkYICxgCKkBpExLtLEsvN8RYNuGi5cJoBGk8dgF6EHn0LC/dbOn7qaH57nUEDuH9Qz8VQBODFjL9zCVYMtVZ2dd7ZTKDJEMGEgydynn4ZDZCzbFOoJMaDHbMLKm6XvRPrmH2HyIw7zsWKe33D8DI6CCi+iQzT2Og948ETb+Lyq3BGn4KryKJ28fwvZWFUfL/911KR8SqKrYBNgYUQV5QDQ9wqCktp5Y4sX4t4+HL339I67qn9YSOJtNQhvnfLVGBHGbZIpvk+Cb/tbN4fzfqoIB/fJrgI2kqjBzCLww4ivlJ1YXHjwtngJ+c3Sp3yD3Ee43Lz/gxefFZ0oCpvBKde8I2gofR98vj3y1thrVERsyR48vZY8B5V3FEBQAVD8Mjz/gjJf4HemS67Z/NhtuJyQvlczWT2iK3XjdSOijbIn6/7MCULkv6PJ6hLDBers8YAQ=="}],"stop_reason":null,"stop_sequence":null,"usage":{"input_tokens":3,"cache_creation_input_tokens":293,"cache_read_input_tokens":59449,"cache_creation":{"ephemeral_5m_input_tokens":0,"ephemeral_1h_input_tokens":293},"output_tokens":9,"service_tier":"standard","inference_geo":"not_available"}},"requestId":"req_011CZ9yQ7kJKHbqq9LRaoxzW","type":"assistant","uuid":"7d669292-b702-4298-9bd7-6e46b9569e13","timestamp":"2026-03-18T05:13:05.071Z","userType":"external","entrypoint":"cli","cwd":"/Users/jan/prg/ClusterCockpit/cc-backend","sessionId":"5eb20a94-f8df-4979-a0ae-2aa99bfad884","version":"2.1.78","gitBranch":"hotfix","slug":"bright-wandering-flurry"} +{"parentUuid":"7d669292-b702-4298-9bd7-6e46b9569e13","isSidechain":false,"message":{"model":"claude-opus-4-6","id":"msg_01Nw8UrrC9B797Lj6AbS3W8L","type":"message","role":"assistant","content":[{"type":"tool_use","id":"toolu_01GjudvbWGrHp3QEXV6FV9oH","name":"Grep","input":{"pattern":"GOMAXPROCS|runtime\\.SetMax|NumCPU|num.?thread|maxprocs","-i":true,"output_mode":"content"},"caller":{"type":"direct"}}],"stop_reason":"tool_use","stop_sequence":null,"usage":{"input_tokens":3,"cache_creation_input_tokens":293,"cache_read_input_tokens":59449,"output_tokens":169,"server_tool_use":{"web_search_requests":0,"web_fetch_requests":0},"service_tier":"standard","cache_creation":{"ephemeral_1h_input_tokens":293,"ephemeral_5m_input_tokens":0},"inference_geo":"","iterations":[],"speed":"standard"}},"requestId":"req_011CZ9yQ7kJKHbqq9LRaoxzW","type":"assistant","uuid":"56a51a03-d394-4129-bfd2-6d6d4fbc335b","timestamp":"2026-03-18T05:13:06.494Z","userType":"external","entrypoint":"cli","cwd":"/Users/jan/prg/ClusterCockpit/cc-backend","sessionId":"5eb20a94-f8df-4979-a0ae-2aa99bfad884","version":"2.1.78","gitBranch":"hotfix","slug":"bright-wandering-flurry"} +{"parentUuid":"56a51a03-d394-4129-bfd2-6d6d4fbc335b","isSidechain":false,"type":"progress","data":{"type":"hook_progress","hookEvent":"PostToolUse","hookName":"PostToolUse:Grep","command":"callback"},"parentToolUseID":"toolu_01GjudvbWGrHp3QEXV6FV9oH","toolUseID":"toolu_01GjudvbWGrHp3QEXV6FV9oH","timestamp":"2026-03-18T05:13:06.528Z","uuid":"2e73853a-8fa3-45d0-b3e1-6bf74f7b8de9","userType":"external","entrypoint":"cli","cwd":"/Users/jan/prg/ClusterCockpit/cc-backend","sessionId":"5eb20a94-f8df-4979-a0ae-2aa99bfad884","version":"2.1.78","gitBranch":"hotfix","slug":"bright-wandering-flurry"} +{"parentUuid":"56a51a03-d394-4129-bfd2-6d6d4fbc335b","isSidechain":false,"promptId":"c62ad23e-e8a3-4176-91e2-f7b7a7cd0185","type":"user","message":{"role":"user","content":[{"tool_use_id":"toolu_01GjudvbWGrHp3QEXV6FV9oH","type":"tool_result","content":"pkg/metricstore/metricstore.go:109:// 2. Configures worker pool size (defaults to NumCPU/2+1, max 10)\npkg/metricstore/metricstore.go:138:\t\tKeys.NumWorkers = min(runtime.NumCPU()/2+1, DefaultMaxWorkers)\nconfigs/startJobPayload.json:18: \"slurmInfo\": \"JobId=398759\\nJobName=myJob\\nUserId=dummyUser\\nGroupId=dummyGroup\\nAccount=dummyAccount\\nQOS=normal Requeue=False Restarts=0 BatchFlag=True\\nTimeLimit=1439'\\nSubmitTime=2023-02-09T14:10:18\\nPartition=singlenode\\nNodeList=xx\\nNumNodes=xx NumCPUs=72 NumTasks=72 CPUs/Task=1\\nNTasksPerNode:Socket:Core=0:None:None\\nTRES_req=cpu=72,mem=250000M,node=1,billing=72\\nTRES_alloc=cpu=72,node=1,billing=72\\nCommand=myCmd\\nWorkDir=myDir\\nStdErr=\\nStdOut=\\n\",\npkg/metricstore/config.go:114:// - NumWorkers: Parallel workers for checkpoint/archive (0 = auto: min(NumCPU/2+1, 10))\npkg/metricstore/config.go:123:\t// If not set or 0, defaults to min(runtime.NumCPU()/2+1, 10)\ninternal/graph/schema.resolvers.go:788:\t\tnumThreadsInt := int(job.NumHWThreads)\ninternal/graph/schema.resolvers.go:798:\t\t\tNumHWThreads: &numThreadsInt,\ninternal/importer/testdata/meta-fritzError.input:1:[Omitted long matching line]\nweb/frontend/src/generic/filters/Resources.svelte:262: \nweb/frontend/src/generic/filters/Resources.svelte:264: "}]},"uuid":"ad5e78a7-7123-4e8c-bac4-7d91f88b0d92","timestamp":"2026-03-18T05:13:06.528Z","toolUseResult":{"mode":"content","numFiles":0,"filenames":[],"content":"pkg/metricstore/metricstore.go:109:// 2. Configures worker pool size (defaults to NumCPU/2+1, max 10)\npkg/metricstore/metricstore.go:138:\t\tKeys.NumWorkers = min(runtime.NumCPU()/2+1, DefaultMaxWorkers)\nconfigs/startJobPayload.json:18: \"slurmInfo\": \"JobId=398759\\nJobName=myJob\\nUserId=dummyUser\\nGroupId=dummyGroup\\nAccount=dummyAccount\\nQOS=normal Requeue=False Restarts=0 BatchFlag=True\\nTimeLimit=1439'\\nSubmitTime=2023-02-09T14:10:18\\nPartition=singlenode\\nNodeList=xx\\nNumNodes=xx NumCPUs=72 NumTasks=72 CPUs/Task=1\\nNTasksPerNode:Socket:Core=0:None:None\\nTRES_req=cpu=72,mem=250000M,node=1,billing=72\\nTRES_alloc=cpu=72,node=1,billing=72\\nCommand=myCmd\\nWorkDir=myDir\\nStdErr=\\nStdOut=\\n\",\npkg/metricstore/config.go:114:// - NumWorkers: Parallel workers for checkpoint/archive (0 = auto: min(NumCPU/2+1, 10))\npkg/metricstore/config.go:123:\t// If not set or 0, defaults to min(runtime.NumCPU()/2+1, 10)\ninternal/graph/schema.resolvers.go:788:\t\tnumThreadsInt := int(job.NumHWThreads)\ninternal/graph/schema.resolvers.go:798:\t\t\tNumHWThreads: &numThreadsInt,\ninternal/importer/testdata/meta-fritzError.input:1:[Omitted long matching line]\nweb/frontend/src/generic/filters/Resources.svelte:262: \nweb/frontend/src/generic/filters/Resources.svelte:264: ","numLines":10},"sourceToolAssistantUUID":"56a51a03-d394-4129-bfd2-6d6d4fbc335b","userType":"external","entrypoint":"cli","cwd":"/Users/jan/prg/ClusterCockpit/cc-backend","sessionId":"5eb20a94-f8df-4979-a0ae-2aa99bfad884","version":"2.1.78","gitBranch":"hotfix","slug":"bright-wandering-flurry"} +{"parentUuid":"ad5e78a7-7123-4e8c-bac4-7d91f88b0d92","isSidechain":false,"message":{"model":"claude-opus-4-6","id":"msg_013yveZgugK9Pi45NXCo8ypj","type":"message","role":"assistant","content":[{"type":"text","text":"**No, `GOMAXPROCS` is never set explicitly in this application.** It uses the Go default, which equals the number of logical CPUs visible to the process (i.e., `runtime.NumCPU()`). It is not configurable via `config.json` or any flag.\n\nTo clarify the distinction:\n\n- **OS threads (`GOMAXPROCS`)**: Controls how many goroutines can execute *simultaneously* on OS threads. Defaults to `runtime.NumCPU()`. Not set or configurable anywhere in cc-backend.\n- **`NumWorkers`** (`config.go:124`): Controls the number of *goroutines* for checkpoint/archive worker pools. Defaults to `min(NumCPU/2+1, 10)`. Configurable via `\"num-workers\"` in `config.json`. After our change, this also controls the NATS decode worker count.\n\nSo on a 16-core machine you'd get `GOMAXPROCS=16` (up to 16 OS threads running goroutines) and `NumWorkers=9` (9 goroutines in each worker pool). The goroutines are multiplexed onto the OS threads by the Go scheduler — they're not 1:1.\n\nWould you like to make `GOMAXPROCS` configurable, or is the current default sufficient?"}],"stop_reason":"end_turn","stop_sequence":null,"usage":{"input_tokens":1,"cache_creation_input_tokens":757,"cache_read_input_tokens":59742,"output_tokens":313,"server_tool_use":{"web_search_requests":0,"web_fetch_requests":0},"service_tier":"standard","cache_creation":{"ephemeral_1h_input_tokens":757,"ephemeral_5m_input_tokens":0},"inference_geo":"","iterations":[],"speed":"standard"}},"requestId":"req_011CZ9yQaaqeYbm1Gb7KGf7J","type":"assistant","uuid":"93b6933b-1d8d-4933-afae-ec5854218fc2","timestamp":"2026-03-18T05:13:16.482Z","userType":"external","entrypoint":"cli","cwd":"/Users/jan/prg/ClusterCockpit/cc-backend","sessionId":"5eb20a94-f8df-4979-a0ae-2aa99bfad884","version":"2.1.78","gitBranch":"hotfix","slug":"bright-wandering-flurry"} +{"parentUuid":"93b6933b-1d8d-4933-afae-ec5854218fc2","isSidechain":false,"type":"progress","data":{"type":"hook_progress","hookEvent":"Stop","hookName":"Stop","command":"entire hooks claude-code stop"},"parentToolUseID":"929dc0e2-2aa7-4793-9845-1a2fcdc5b528","toolUseID":"929dc0e2-2aa7-4793-9845-1a2fcdc5b528","timestamp":"2026-03-18T05:13:16.493Z","uuid":"12c094c2-ae20-485e-a44a-5a96aef785f1","userType":"external","entrypoint":"cli","cwd":"/Users/jan/prg/ClusterCockpit/cc-backend","sessionId":"5eb20a94-f8df-4979-a0ae-2aa99bfad884","version":"2.1.78","gitBranch":"hotfix","slug":"bright-wandering-flurry"} +{"parentUuid":"12c094c2-ae20-485e-a44a-5a96aef785f1","isSidechain":false,"type":"system","subtype":"stop_hook_summary","hookCount":1,"hookInfos":[{"command":"entire hooks claude-code stop","durationMs":551}],"hookErrors":[],"preventedContinuation":false,"stopReason":"","hasOutput":false,"level":"suggestion","timestamp":"2026-03-18T05:13:17.044Z","uuid":"64504fb4-bbd1-4c21-8369-ce3ce49a7275","toolUseID":"929dc0e2-2aa7-4793-9845-1a2fcdc5b528","userType":"external","entrypoint":"cli","cwd":"/Users/jan/prg/ClusterCockpit/cc-backend","sessionId":"5eb20a94-f8df-4979-a0ae-2aa99bfad884","version":"2.1.78","gitBranch":"hotfix","slug":"bright-wandering-flurry"} diff --git a/7e/68050cab59/0/metadata.json b/7e/68050cab59/0/metadata.json new file mode 100644 index 00000000..1f24d19f --- /dev/null +++ b/7e/68050cab59/0/metadata.json @@ -0,0 +1,35 @@ +{ + "cli_version": "0.5.0", + "checkpoint_id": "7e68050cab59", + "session_id": "5eb20a94-f8df-4979-a0ae-2aa99bfad884", + "strategy": "manual-commit", + "created_at": "2026-03-18T05:14:15.937779Z", + "branch": "hotfix", + "checkpoints_count": 3, + "files_touched": [ + "pkg/metricstore/lineprotocol.go", + "pkg/metricstore/metricstore.go", + "pkg/metricstore/walCheckpoint.go" + ], + "agent": "Claude Code", + "turn_id": "ee511b5a4551", + "token_usage": { + "input_tokens": 24, + "cache_creation_tokens": 46456, + "cache_read_tokens": 882339, + "output_tokens": 4423, + "api_call_count": 18 + }, + "session_metrics": { + "turn_count": 3 + }, + "initial_attribution": { + "calculated_at": "2026-03-18T05:14:15.784275Z", + "agent_lines": 40, + "human_added": 0, + "human_modified": 0, + "human_removed": 0, + "total_committed": 40, + "agent_percentage": 100 + } +} diff --git a/7e/68050cab59/0/prompt.txt b/7e/68050cab59/0/prompt.txt new file mode 100644 index 00000000..eb15e0cf --- /dev/null +++ b/7e/68050cab59/0/prompt.txt @@ -0,0 +1,5 @@ +Does a similar problem occur on the metricstore REST API path? + +--- + +How many os level threads are used in this application? It is currently configurable? \ No newline at end of file diff --git a/7e/68050cab59/metadata.json b/7e/68050cab59/metadata.json new file mode 100644 index 00000000..ff50e125 --- /dev/null +++ b/7e/68050cab59/metadata.json @@ -0,0 +1,27 @@ +{ + "cli_version": "0.5.0", + "checkpoint_id": "7e68050cab59", + "strategy": "manual-commit", + "branch": "hotfix", + "checkpoints_count": 3, + "files_touched": [ + "pkg/metricstore/lineprotocol.go", + "pkg/metricstore/metricstore.go", + "pkg/metricstore/walCheckpoint.go" + ], + "sessions": [ + { + "metadata": "/7e/68050cab59/0/metadata.json", + "transcript": "/7e/68050cab59/0/full.jsonl", + "content_hash": "/7e/68050cab59/0/content_hash.txt", + "prompt": "/7e/68050cab59/0/prompt.txt" + } + ], + "token_usage": { + "input_tokens": 24, + "cache_creation_tokens": 46456, + "cache_read_tokens": 882339, + "output_tokens": 4423, + "api_call_count": 18 + } +}