cc-metric-store/ReleaseNotes.md

cc-metric-store version 1.5.3

This is a bugfix release of cc-metric-store, the metric timeseries cache implementation of ClusterCockpit. Since the storage engine is now part of cc-backend we will follow the version number of cc-backend. For release specific notes visit the ClusterCockpit Documentation.

Notable changes

• -cleanup-checkpoints CLI flag: New flag triggers checkpoint cleanup (delete or archive to Parquet) based on the configured retention and cleanup settings, then exits. Useful for one-off maintenance without starting the full server.
• GC initialised before checkpoint load: GOGC=15 is now set before metricstore.Init so the garbage-collector baseline is established prior to the largest allocation event (loading checkpoints from disk), reducing unnecessary heap growth at startup.
• Dependency upgrades: cc-backend updated from v1.5.0 to v1.5.3; cc-lib updated from v2.8.0 to v2.11.0; nats.go bumped from v1.49.0 to v1.50.0; parquet-go bumped from v0.28.0 to v0.29.0; various other module upgrades.

Metricstore package fixes (cc-backend v1.5.0 → v1.5.3)

The following fixes landed in the upstream cc-backend/pkg/metricstore package and are included via the dependency upgrade:

• WAL correctness: Fixed WAL rotation being skipped for all nodes due to a non-blocking send on a too-small channel; fixed unbound growth of WAL files when a checkpointing error occurs; fixed bugs in the WAL journal pipeline.
• WAL throughput: Sharded the WAL consumer for higher write throughput; added buffered I/O to WAL writes.
• Checkpoint stability: Paused WAL writes during binary checkpoint creation to prevent message drops; restructured cleanup archiving to stay within the 32 k row limit of parquet-go.
• Memory: Fixed a memory explosion caused by broken emergency-free and batch aborts; reduced memory usage in the Parquet checkpoint archiver; fixed preventing memory spikes in the Parquet writer during the move/archive policy.
• NATS: Fixed blocking ReceiveNats call; fixed NATS contention under load.
• Shutdown: Increased shutdown timeouts; added WAL flush interval tuning; added shutdown timing logs.
• Observability: Added verbose logs for DataDoesNotAlign errors; reduced noise by demoting a missing-metric warning to debug level.
• Configuration: Restored checkpointInterval as an optional config key.

Breaking changes (from v1.4.x)

• The internal memorystore, avro, resampler, and util packages have been removed. The storage engine is now provided by the cc-backend package (cc-backend/pkg/metricstore). This repository is now the HTTP API wrapper only.
• The configuration schema has changed. Refer to configs/config.json for the updated structure.