Replace explicit resampling config with policy based approach

Entire-Checkpoint: f69e38210bb1

internal/config/config.go

@@ -112,6 +112,8 @@ type ResampleConfig struct {
 	Resolutions []int `json:"resolutions"`
 	// Trigger next zoom level at less than this many visible datapoints
 	Trigger int `json:"trigger"`
+	// Policy-derived target point count (set dynamically from user preference, not from config.json)
+	TargetPoints int `json:"targetPoints,omitempty"`
 }
 
 type NATSConfig struct {

internal/graph/resample.go

@@ -0,0 +1,113 @@
+// Copyright (C) NHR@FAU, University Erlangen-Nuremberg.
+// All rights reserved. This file is part of cc-backend.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+package graph
+
+import (
+	"context"
+	"strings"
+
+	"github.com/ClusterCockpit/cc-backend/internal/graph/model"
+	"github.com/ClusterCockpit/cc-backend/internal/metricdispatch"
+	"github.com/ClusterCockpit/cc-backend/internal/repository"
+	"github.com/ClusterCockpit/cc-backend/pkg/archive"
+)
+
+// resolveResolutionFromPolicy reads the user's resample policy preference and
+// computes a resolution based on job duration and metric frequency. Returns nil
+// if the user has no policy set.
+func resolveResolutionFromPolicy(ctx context.Context, duration int64, cluster string, metrics []string) *int {
+	user := repository.GetUserFromContext(ctx)
+	if user == nil {
+		return nil
+	}
+
+	conf, err := repository.GetUserCfgRepo().GetUIConfig(user)
+	if err != nil {
+		return nil
+	}
+
+	policyVal, ok := conf["plotConfiguration_resamplePolicy"]
+	if !ok {
+		return nil
+	}
+	policyStr, ok := policyVal.(string)
+	if !ok || policyStr == "" {
+		return nil
+	}
+
+	policy := metricdispatch.ResamplePolicy(policyStr)
+	targetPoints := metricdispatch.TargetPointsForPolicy(policy)
+	if targetPoints == 0 {
+		return nil
+	}
+
+	// Find the smallest metric frequency across the requested metrics
+	frequency := smallestFrequency(cluster, metrics)
+	if frequency <= 0 {
+		return nil
+	}
+
+	res := metricdispatch.ComputeResolution(duration, int64(frequency), targetPoints)
+	return &res
+}
+
+// resolveResampleAlgo returns the resampling algorithm name to use, checking
+// the explicit GraphQL parameter first, then the user's preference.
+func resolveResampleAlgo(ctx context.Context, resampleAlgo *model.ResampleAlgo) string {
+	if resampleAlgo != nil {
+		return strings.ToLower(resampleAlgo.String())
+	}
+
+	user := repository.GetUserFromContext(ctx)
+	if user == nil {
+		return ""
+	}
+
+	conf, err := repository.GetUserCfgRepo().GetUIConfig(user)
+	if err != nil {
+		return ""
+	}
+
+	algoVal, ok := conf["plotConfiguration_resampleAlgo"]
+	if !ok {
+		return ""
+	}
+	algoStr, ok := algoVal.(string)
+	if !ok {
+		return ""
+	}
+
+	return algoStr
+}
+
+// smallestFrequency returns the smallest metric timestep (in seconds) among the
+// requested metrics for the given cluster. Falls back to 0 if nothing is found.
+func smallestFrequency(cluster string, metrics []string) int {
+	cl := archive.GetCluster(cluster)
+	if cl == nil {
+		return 0
+	}
+
+	minFreq := 0
+	for _, mc := range cl.MetricConfig {
+		if len(metrics) > 0 {
+			found := false
+			for _, m := range metrics {
+				if mc.Name == m {
+					found = true
+					break
+				}
+			}
+			if !found {
+				continue
+			}
+		}
+		if minFreq == 0 || mc.Timestep < minFreq {
+			minFreq = mc.Timestep
+		}
+	}
+
+	return minFreq
+}

internal/graph/schema.resolvers.go

@@ -499,26 +499,27 @@ func (r *queryResolver) Job(ctx context.Context, id string) (*schema.Job, error)
 
 // JobMetrics is the resolver for the jobMetrics field.
 func (r *queryResolver) JobMetrics(ctx context.Context, id string, metrics []string, scopes []schema.MetricScope, resolution *int, resampleAlgo *model.ResampleAlgo) ([]*model.JobMetricWithName, error) {
-	if resolution == nil { // Load from Config
-		if config.Keys.EnableResampling != nil {
-			defaultRes := slices.Max(config.Keys.EnableResampling.Resolutions)
-			resolution = &defaultRes
-		} else { // Set 0 (Loads configured metric timestep)
-			defaultRes := 0
-			resolution = &defaultRes
-		}
-	}
-
 	job, err := r.Query().Job(ctx, id)
 	if err != nil {
 		cclog.Warn("Error while querying job for metrics")
 		return nil, err
 	}
 
-	algoName := ""
-	if resampleAlgo != nil {
-		algoName = strings.ToLower(resampleAlgo.String())
+	// Resolve resolution: explicit param > user policy > global config > 0
+	if resolution == nil {
+		resolution = resolveResolutionFromPolicy(ctx, int64(job.Duration), job.Cluster, metrics)
 	}
+	if resolution == nil {
+		if config.Keys.EnableResampling != nil {
+			defaultRes := slices.Max(config.Keys.EnableResampling.Resolutions)
+			resolution = &defaultRes
+		} else {
+			defaultRes := 0
+			resolution = &defaultRes
+		}
+	}
+
+	algoName := resolveResampleAlgo(ctx, resampleAlgo)
 
 	data, err := metricdispatch.LoadData(job, metrics, scopes, ctx, *resolution, algoName)
 	if err != nil {
@@ -878,11 +879,16 @@ func (r *queryResolver) NodeMetrics(ctx context.Context, cluster string, nodes [
 
 // NodeMetricsList is the resolver for the nodeMetricsList field.
 func (r *queryResolver) NodeMetricsList(ctx context.Context, cluster string, subCluster string, stateFilter string, nodeFilter string, scopes []schema.MetricScope, metrics []string, from time.Time, to time.Time, page *model.PageRequest, resolution *int, resampleAlgo *model.ResampleAlgo) (*model.NodesResultList, error) {
-	if resolution == nil { // Load from Config
+	// Resolve resolution: explicit param > user policy > global config > 0
+	duration := int64(to.Sub(from).Seconds())
+	if resolution == nil {
+		resolution = resolveResolutionFromPolicy(ctx, duration, cluster, metrics)
+	}
+	if resolution == nil {
 		if config.Keys.EnableResampling != nil {
 			defaultRes := slices.Max(config.Keys.EnableResampling.Resolutions)
 			resolution = &defaultRes
-		} else { // Set 0 (Loads configured metric timestep)
+		} else {
 			defaultRes := 0
 			resolution = &defaultRes
 		}
@@ -906,10 +912,7 @@ func (r *queryResolver) NodeMetricsList(ctx context.Context, cluster string, sub
 		}
 	}
 
-	algoName := ""
-	if resampleAlgo != nil {
-		algoName = strings.ToLower(resampleAlgo.String())
-	}
+	algoName := resolveResampleAlgo(ctx, resampleAlgo)
 
 	// data -> map hostname:jobdata
 	data, err := metricdispatch.LoadNodeListData(cluster, subCluster, nodes, metrics, scopes, *resolution, from, to, ctx, algoName)

internal/metricdispatch/resamplepolicy.go

@@ -0,0 +1,49 @@
+// Copyright (C) NHR@FAU, University Erlangen-Nuremberg.
+// All rights reserved. This file is part of cc-backend.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+package metricdispatch
+
+import "math"
+
+type ResamplePolicy string
+
+const (
+	ResamplePolicyLow    ResamplePolicy = "low"
+	ResamplePolicyMedium ResamplePolicy = "medium"
+	ResamplePolicyHigh   ResamplePolicy = "high"
+)
+
+// TargetPointsForPolicy returns the target number of data points for a given policy.
+func TargetPointsForPolicy(policy ResamplePolicy) int {
+	switch policy {
+	case ResamplePolicyLow:
+		return 200
+	case ResamplePolicyMedium:
+		return 500
+	case ResamplePolicyHigh:
+		return 1000
+	default:
+		return 0
+	}
+}
+
+// ComputeResolution computes the resampling resolution in seconds for a given
+// job duration, metric frequency, and target point count. Returns 0 if the
+// total number of data points is already at or below targetPoints (no resampling needed).
+func ComputeResolution(duration int64, frequency int64, targetPoints int) int {
+	if frequency <= 0 || targetPoints <= 0 || duration <= 0 {
+		return 0
+	}
+
+	totalPoints := duration / frequency
+	if totalPoints <= int64(targetPoints) {
+		return 0
+	}
+
+	targetRes := math.Ceil(float64(duration) / float64(targetPoints))
+	// Round up to nearest multiple of frequency
+	resolution := int(math.Ceil(targetRes/float64(frequency))) * int(frequency)
+
+	return resolution
+}

internal/metricdispatch/resamplepolicy_test.go

@@ -0,0 +1,68 @@
+// Copyright (C) NHR@FAU, University Erlangen-Nuremberg.
+// All rights reserved. This file is part of cc-backend.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+package metricdispatch
+
+import "testing"
+
+func TestTargetPointsForPolicy(t *testing.T) {
+	tests := []struct {
+		policy ResamplePolicy
+		want   int
+	}{
+		{ResamplePolicyLow, 200},
+		{ResamplePolicyMedium, 500},
+		{ResamplePolicyHigh, 1000},
+		{ResamplePolicy("unknown"), 0},
+		{ResamplePolicy(""), 0},
+	}
+
+	for _, tt := range tests {
+		if got := TargetPointsForPolicy(tt.policy); got != tt.want {
+			t.Errorf("TargetPointsForPolicy(%q) = %d, want %d", tt.policy, got, tt.want)
+		}
+	}
+}
+
+func TestComputeResolution(t *testing.T) {
+	tests := []struct {
+		name         string
+		duration     int64
+		frequency    int64
+		targetPoints int
+		want         int
+	}{
+		// 24h job, 60s frequency, 1440 total points
+		{"low_24h_60s", 86400, 60, 200, 480},
+		{"medium_24h_60s", 86400, 60, 500, 180},
+		{"high_24h_60s", 86400, 60, 1000, 120},
+
+		// 2h job, 60s frequency, 120 total points — no resampling needed
+		{"low_2h_60s", 7200, 60, 200, 0},
+		{"medium_2h_60s", 7200, 60, 500, 0},
+		{"high_2h_60s", 7200, 60, 1000, 0},
+
+		// Edge: zero/negative inputs
+		{"zero_duration", 0, 60, 200, 0},
+		{"zero_frequency", 86400, 0, 200, 0},
+		{"zero_target", 86400, 60, 0, 0},
+		{"negative_duration", -100, 60, 200, 0},
+
+		// 12h job, 30s frequency, 1440 total points
+		{"medium_12h_30s", 43200, 30, 500, 90},
+
+		// Exact fit: total points == target points
+		{"exact_fit", 12000, 60, 200, 0},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := ComputeResolution(tt.duration, tt.frequency, tt.targetPoints)
+			if got != tt.want {
+				t.Errorf("ComputeResolution(%d, %d, %d) = %d, want %d",
+					tt.duration, tt.frequency, tt.targetPoints, got, tt.want)
+			}
+		})
+	}
+}

internal/routerConfig/routes.go

@@ -15,6 +15,7 @@ import (
 
 	"github.com/ClusterCockpit/cc-backend/internal/config"
 	"github.com/ClusterCockpit/cc-backend/internal/graph/model"
+	"github.com/ClusterCockpit/cc-backend/internal/metricdispatch"
 	"github.com/ClusterCockpit/cc-backend/internal/repository"
 	"github.com/ClusterCockpit/cc-backend/web"
 	cclog "github.com/ClusterCockpit/cc-lib/v2/ccLogger"
@@ -493,13 +494,15 @@ func SetupRoutes(router chi.Router, buildInfo web.Build) {
 			// Get Roles
 			availableRoles, _ := schema.GetValidRolesMap(user)
 
+			resampling := resamplingForUser(conf)
+
 			page := web.Page{
 				Title:      title,
 				User:       *user,
 				Roles:      availableRoles,
 				Build:      buildInfo,
 				Config:     conf,
-				Resampling: config.Keys.EnableResampling,
+				Resampling: resampling,
 				Infos:      infos,
 			}
 
@@ -586,3 +589,32 @@ func HandleSearchBar(rw http.ResponseWriter, r *http.Request, buildInfo web.Buil
 		web.RenderTemplate(rw, "message.tmpl", &web.Page{Title: "Warning", MsgType: "alert-warning", Message: "Empty search", User: *user, Roles: availableRoles, Build: buildInfo})
 	}
 }
+
+// resamplingForUser returns a ResampleConfig that incorporates the user's
+// resample policy preference. If the user has a policy set, it creates a
+// policy-derived config with targetPoints and trigger. Otherwise falls back
+// to the global config.
+func resamplingForUser(conf map[string]any) *config.ResampleConfig {
+	globalCfg := config.Keys.EnableResampling
+
+	policyVal, ok := conf["plotConfiguration_resamplePolicy"]
+	if !ok {
+		return globalCfg
+	}
+	policyStr, ok := policyVal.(string)
+	if !ok || policyStr == "" {
+		return globalCfg
+	}
+
+	policy := metricdispatch.ResamplePolicy(policyStr)
+	targetPoints := metricdispatch.TargetPointsForPolicy(policy)
+	if targetPoints == 0 {
+		return globalCfg
+	}
+
+	// Build a policy-derived config: targetPoints + trigger, no resolutions array
+	return &config.ResampleConfig{
+		TargetPoints: targetPoints,
+		Trigger:      targetPoints / 4,
+	}
+}