feat: refactoring thresholds and usage assessment

this commit refactors the thresholds and usage assessment for the node
utilization plugins. both high and low plugins are affected by this
change.

go.mod

@@ -32,6 +32,8 @@ require (
 	sigs.k8s.io/yaml v1.4.0
 )
 
+require golang.org/x/exp v0.0.0-20240719175910-8a7402abbf56
+
 require (
 	cel.dev/expr v0.18.0 // indirect
 	github.com/BurntSushi/toml v0.3.1 // indirect
@@ -98,7 +100,6 @@ require (
 	go.uber.org/multierr v1.11.0 // indirect
 	go.uber.org/zap v1.27.0 // indirect
 	golang.org/x/crypto v0.31.0 // indirect
-	golang.org/x/exp v0.0.0-20240719175910-8a7402abbf56 // indirect
 	golang.org/x/mod v0.21.0 // indirect
 	golang.org/x/net v0.30.0 // indirect
 	golang.org/x/oauth2 v0.23.0 // indirect

pkg/framework/plugins/nodeutilization/highnodeutilization.go

@@ -28,6 +28,7 @@ import (
 	nodeutil "sigs.k8s.io/descheduler/pkg/descheduler/node"
 
 	podutil "sigs.k8s.io/descheduler/pkg/descheduler/pod"
+	"sigs.k8s.io/descheduler/pkg/framework/plugins/nodeutilization/normalizer"
 	frameworktypes "sigs.k8s.io/descheduler/pkg/framework/types"
 )
 
@@ -42,6 +43,7 @@ type HighNodeUtilization struct {
 	podFilter                func(pod *v1.Pod) bool
 	underutilizationCriteria []interface{}
 	resourceNames            []v1.ResourceName
+	extendedResourceNames    []v1.ResourceName
 	targetThresholds         api.ResourceThresholds
 	usageClient              usageClient
 }
@@ -57,7 +59,7 @@ func NewHighNodeUtilization(args runtime.Object, handle frameworktypes.Handle) (
 
 	targetThresholds := make(api.ResourceThresholds)
 	setDefaultForThresholds(highNodeUtilizatioArgs.Thresholds, targetThresholds)
-	resourceNames := getResourceNames(targetThresholds)
+	resourceNames := getResourceNames(highNodeUtilizatioArgs.Thresholds)
 
 	underutilizationCriteria := []interface{}{
 		"CPU", highNodeUtilizatioArgs.Thresholds[v1.ResourceCPU],
@@ -77,14 +79,19 @@ func NewHighNodeUtilization(args runtime.Object, handle frameworktypes.Handle) (
 		return nil, fmt.Errorf("error initializing pod filter function: %v", err)
 	}
 
+	extendedResourceNames := uniquifyResourceNames(
+		append(resourceNames, v1.ResourceCPU, v1.ResourceMemory, v1.ResourcePods),
+	)
+
 	return &HighNodeUtilization{
 		handle:                   handle,
 		args:                     highNodeUtilizatioArgs,
 		resourceNames:            resourceNames,
+		extendedResourceNames:    extendedResourceNames,
 		targetThresholds:         targetThresholds,
 		underutilizationCriteria: underutilizationCriteria,
 		podFilter:                podFilter,
-		usageClient:              newRequestedUsageClient(resourceNames, handle.GetPodsAssignedToNodeFunc()),
+		usageClient:              newRequestedUsageClient(extendedResourceNames, handle.GetPodsAssignedToNodeFunc()),
 	}, nil
 }
 
@@ -102,11 +109,18 @@ func (h *HighNodeUtilization) Balance(ctx context.Context, nodes []*v1.Node) *fr
 	}
 
 	nodesMap, nodesUsageMap, podListMap := getNodeUsageSnapshot(nodes, h.usageClient)
-	nodeThresholdsMap := getStaticNodeThresholds(nodes, h.args.Thresholds, h.targetThresholds)
-	nodesUsageAsNodeThresholdsMap := nodeUsageToResourceThresholds(nodesUsageMap, nodesMap)
+	capacities := referencedResourceListForNodesCapacity(nodes)
+
+	usage, thresholds := assessNodesUsagesAndStaticThresholds(
+		nodesUsageMap,
+		capacities,
+		h.args.Thresholds,
+		h.targetThresholds,
+	)
+
 	nodeGroups := classifyNodeUsage(
-		nodesUsageAsNodeThresholdsMap,
-		nodeThresholdsMap,
+		usage,
+		thresholds,
 		[]classifierFnc{
 			// underutilized nodes
 			func(nodeName string, usage, threshold api.ResourceThresholds) bool {
@@ -128,7 +142,12 @@ func (h *HighNodeUtilization) Balance(ctx context.Context, nodes []*v1.Node) *fr
 	category := []string{"underutilized", "overutilized"}
 	for i := range nodeGroups {
 		for nodeName := range nodeGroups[i] {
-			klog.InfoS("Node is "+category[i], "node", klog.KObj(nodesMap[nodeName]), "usage", nodesUsageMap[nodeName], "usagePercentage", resourceUsagePercentages(nodesUsageMap[nodeName], nodesMap[nodeName], true))
+			klog.InfoS(
+				fmt.Sprintf("Node is %s", category[i]),
+				"node", klog.KObj(nodesMap[nodeName]),
+				"usage", nodesUsageMap[nodeName],
+				"usagePercentage", normalizer.Round(usage[nodeName]),
+			)
 			nodeInfos[i] = append(nodeInfos[i], NodeInfo{
 				NodeUsage: NodeUsage{
 					node:    nodesMap[nodeName],
@@ -136,8 +155,8 @@ func (h *HighNodeUtilization) Balance(ctx context.Context, nodes []*v1.Node) *fr
 					allPods: podListMap[nodeName],
 				},
 				thresholds: NodeThresholds{
-					lowResourceThreshold:  resourceThresholdsToNodeUsage(nodeThresholdsMap[nodeName][0], nodesMap[nodeName]),
-					highResourceThreshold: resourceThresholdsToNodeUsage(nodeThresholdsMap[nodeName][1], nodesMap[nodeName]),
+					lowResourceThreshold:  resourceThresholdsToNodeUsage(thresholds[nodeName][0], capacities[nodeName], h.extendedResourceNames),
+					highResourceThreshold: resourceThresholdsToNodeUsage(thresholds[nodeName][1], capacities[nodeName], h.extendedResourceNames),
 				},
 			})
 		}
@@ -189,7 +208,7 @@ func (h *HighNodeUtilization) Balance(ctx context.Context, nodes []*v1.Node) *fr
 		h.handle.Evictor(),
 		evictions.EvictOptions{StrategyName: HighNodeUtilizationPluginName},
 		h.podFilter,
-		h.resourceNames,
+		h.extendedResourceNames,
 		continueEvictionCond,
 		h.usageClient,
 		nil,
@@ -199,22 +218,16 @@ func (h *HighNodeUtilization) Balance(ctx context.Context, nodes []*v1.Node) *fr
 }
 
 func setDefaultForThresholds(thresholds, targetThresholds api.ResourceThresholds) {
-	// check if Pods/CPU/Mem are set, if not, set them to 100
-	if _, ok := thresholds[v1.ResourcePods]; !ok {
-		thresholds[v1.ResourcePods] = MaxResourcePercentage
+	if _, ok := thresholds[v1.ResourcePods]; ok {
+		targetThresholds[v1.ResourcePods] = MaxResourcePercentage
 	}
-	if _, ok := thresholds[v1.ResourceCPU]; !ok {
-		thresholds[v1.ResourceCPU] = MaxResourcePercentage
+	if _, ok := thresholds[v1.ResourceCPU]; ok {
+		targetThresholds[v1.ResourceCPU] = MaxResourcePercentage
 	}
-	if _, ok := thresholds[v1.ResourceMemory]; !ok {
-		thresholds[v1.ResourceMemory] = MaxResourcePercentage
+	if _, ok := thresholds[v1.ResourceMemory]; ok {
+		targetThresholds[v1.ResourceMemory] = MaxResourcePercentage
 	}
 
-	// Default targetThreshold resource values to 100
-	targetThresholds[v1.ResourcePods] = MaxResourcePercentage
-	targetThresholds[v1.ResourceCPU] = MaxResourcePercentage
-	targetThresholds[v1.ResourceMemory] = MaxResourcePercentage
-
 	for name := range thresholds {
 		if !nodeutil.IsBasicResource(name) {
 			targetThresholds[name] = MaxResourcePercentage

pkg/framework/plugins/nodeutilization/highnodeutilization_test.go

@@ -244,7 +244,7 @@ func TestHighNodeUtilization(t *testing.T) {
 			},
 			// All pods are assumed to be burstable (test.BuildTestNode always sets both cpu/memory resource requests to some value)
 			pods: []*v1.Pod{
-				test.BuildTestPod("p1", 400, 0, n1NodeName, func(pod *v1.Pod) {
+				test.BuildTestPod("p1", 0, 0, n1NodeName, func(pod *v1.Pod) {
 					test.SetRSOwnerRef(pod)
 					test.MakeBestEffortPod(pod)
 				}),

pkg/framework/plugins/nodeutilization/lownodeutilization.go

@@ -28,6 +28,7 @@ import (
 	"sigs.k8s.io/descheduler/pkg/descheduler/evictions"
 	nodeutil "sigs.k8s.io/descheduler/pkg/descheduler/node"
 	podutil "sigs.k8s.io/descheduler/pkg/descheduler/pod"
+	"sigs.k8s.io/descheduler/pkg/framework/plugins/nodeutilization/normalizer"
 	frameworktypes "sigs.k8s.io/descheduler/pkg/framework/types"
 )
 
@@ -43,6 +44,7 @@ type LowNodeUtilization struct {
 	underutilizationCriteria []interface{}
 	overutilizationCriteria  []interface{}
 	resourceNames            []v1.ResourceName
+	extendedResourceNames    []v1.ResourceName
 	usageClient              usageClient
 }
 
@@ -55,6 +57,9 @@ func NewLowNodeUtilization(args runtime.Object, handle frameworktypes.Handle) (f
 		return nil, fmt.Errorf("want args to be of type LowNodeUtilizationArgs, got %T", args)
 	}
 
+	resourceNames := getResourceNames(lowNodeUtilizationArgsArgs.Thresholds)
+	extendedResourceNames := resourceNames
+
 	metricsUtilization := lowNodeUtilizationArgsArgs.MetricsUtilization
 	if metricsUtilization != nil && metricsUtilization.Source == api.PrometheusMetrics {
 		if metricsUtilization.Prometheus != nil && metricsUtilization.Prometheus.Query != "" {
@@ -70,7 +75,7 @@ func NewLowNodeUtilization(args runtime.Object, handle frameworktypes.Handle) (f
 			return nil, fmt.Errorf("prometheus query is missing")
 		}
 	} else {
-		setDefaultForLNUThresholds(lowNodeUtilizationArgsArgs.Thresholds, lowNodeUtilizationArgsArgs.TargetThresholds, lowNodeUtilizationArgsArgs.UseDeviationThresholds)
+		extendedResourceNames = uniquifyResourceNames(append(resourceNames, v1.ResourceCPU, v1.ResourceMemory, v1.ResourcePods))
 	}
 
 	underutilizationCriteria := []interface{}{
@@ -102,8 +107,6 @@ func NewLowNodeUtilization(args runtime.Object, handle frameworktypes.Handle) (f
 		return nil, fmt.Errorf("error initializing pod filter function: %v", err)
 	}
 
-	resourceNames := getResourceNames(lowNodeUtilizationArgsArgs.Thresholds)
-
 	var usageClient usageClient
 	// MetricsServer is deprecated, removed once dropped
 	if metricsUtilization != nil {
@@ -112,7 +115,7 @@ func NewLowNodeUtilization(args runtime.Object, handle frameworktypes.Handle) (f
 			if handle.MetricsCollector() == nil {
 				return nil, fmt.Errorf("metrics client not initialized")
 			}
-			usageClient = newActualUsageClient(resourceNames, handle.GetPodsAssignedToNodeFunc(), handle.MetricsCollector())
+			usageClient = newActualUsageClient(extendedResourceNames, handle.GetPodsAssignedToNodeFunc(), handle.MetricsCollector())
 		case metricsUtilization.Source == api.PrometheusMetrics:
 			if handle.PrometheusClient() == nil {
 				return nil, fmt.Errorf("prometheus client not initialized")
@@ -124,7 +127,7 @@ func NewLowNodeUtilization(args runtime.Object, handle frameworktypes.Handle) (f
 			return nil, fmt.Errorf("metrics source is empty")
 		}
 	} else {
-		usageClient = newRequestedUsageClient(resourceNames, handle.GetPodsAssignedToNodeFunc())
+		usageClient = newRequestedUsageClient(extendedResourceNames, handle.GetPodsAssignedToNodeFunc())
 	}
 
 	return &LowNodeUtilization{
@@ -133,6 +136,7 @@ func NewLowNodeUtilization(args runtime.Object, handle frameworktypes.Handle) (f
 		underutilizationCriteria: underutilizationCriteria,
 		overutilizationCriteria:  overutilizationCriteria,
 		resourceNames:            resourceNames,
+		extendedResourceNames:    extendedResourceNames,
 		podFilter:                podFilter,
 		usageClient:              usageClient,
 	}, nil
@@ -152,25 +156,29 @@ func (l *LowNodeUtilization) Balance(ctx context.Context, nodes []*v1.Node) *fra
 	}
 
 	nodesMap, nodesUsageMap, podListMap := getNodeUsageSnapshot(nodes, l.usageClient)
-	var nodeThresholdsMap map[string][]api.ResourceThresholds
+	capacities := referencedResourceListForNodesCapacity(nodes)
+
+	var usage map[string]api.ResourceThresholds
+	var thresholds map[string][]api.ResourceThresholds
 	if l.args.UseDeviationThresholds {
-		thresholds, average := getNodeThresholdsFromAverageNodeUsage(nodes, l.usageClient, l.args.Thresholds, l.args.TargetThresholds)
-		klog.InfoS("Average utilization through all nodes", "utilization", average)
-		// All nodes are expected to have the same thresholds
-		for nodeName := range thresholds {
-			klog.InfoS("Underutilization threshold based on average utilization", "threshold", thresholds[nodeName][0])
-			klog.InfoS("Overutilization threshold based on average utilization", "threshold", thresholds[nodeName][1])
-			break
-		}
-		nodeThresholdsMap = thresholds
+		usage, thresholds = assessNodesUsagesAndRelativeThresholds(
+			filterResourceNamesFromNodeUsage(nodesUsageMap, l.resourceNames),
+			capacities,
+			l.args.Thresholds,
+			l.args.TargetThresholds,
+		)
 	} else {
-		nodeThresholdsMap = getStaticNodeThresholds(nodes, l.args.Thresholds, l.args.TargetThresholds)
+		usage, thresholds = assessNodesUsagesAndStaticThresholds(
+			filterResourceNamesFromNodeUsage(nodesUsageMap, l.resourceNames),
+			capacities,
+			l.args.Thresholds,
+			l.args.TargetThresholds,
+		)
 	}
 
-	nodesUsageAsNodeThresholdsMap := nodeUsageToResourceThresholds(nodesUsageMap, nodesMap)
 	nodeGroups := classifyNodeUsage(
-		nodesUsageAsNodeThresholdsMap,
-		nodeThresholdsMap,
+		usage,
+		thresholds,
 		[]classifierFnc{
 			// underutilization
 			func(nodeName string, usage, threshold api.ResourceThresholds) bool {
@@ -193,7 +201,12 @@ func (l *LowNodeUtilization) Balance(ctx context.Context, nodes []*v1.Node) *fra
 	listedNodes := map[string]struct{}{}
 	for i := range nodeGroups {
 		for nodeName := range nodeGroups[i] {
-			klog.InfoS("Node is "+category[i], "node", klog.KObj(nodesMap[nodeName]), "usage", nodesUsageMap[nodeName], "usagePercentage", resourceUsagePercentages(nodesUsageMap[nodeName], nodesMap[nodeName], true))
+			klog.InfoS(
+				fmt.Sprintf("Node is %s", category[i]),
+				"node", klog.KObj(nodesMap[nodeName]),
+				"usage", nodesUsageMap[nodeName],
+				"usagePercentage", normalizer.Round(usage[nodeName]),
+			)
 			listedNodes[nodeName] = struct{}{}
 			nodeInfos[i] = append(nodeInfos[i], NodeInfo{
 				NodeUsage: NodeUsage{
@@ -202,15 +215,21 @@ func (l *LowNodeUtilization) Balance(ctx context.Context, nodes []*v1.Node) *fra
 					allPods: podListMap[nodeName],
 				},
 				thresholds: NodeThresholds{
-					lowResourceThreshold:  resourceThresholdsToNodeUsage(nodeThresholdsMap[nodeName][0], nodesMap[nodeName]),
-					highResourceThreshold: resourceThresholdsToNodeUsage(nodeThresholdsMap[nodeName][1], nodesMap[nodeName]),
+					lowResourceThreshold:  resourceThresholdsToNodeUsage(thresholds[nodeName][0], capacities[nodeName], append(l.extendedResourceNames, v1.ResourceCPU, v1.ResourceMemory, v1.ResourcePods)),
+					highResourceThreshold: resourceThresholdsToNodeUsage(thresholds[nodeName][1], capacities[nodeName], append(l.extendedResourceNames, v1.ResourceCPU, v1.ResourceMemory, v1.ResourcePods)),
 				},
 			})
 		}
 	}
+
 	for nodeName := range nodesMap {
 		if _, ok := listedNodes[nodeName]; !ok {
-			klog.InfoS("Node is appropriately utilized", "node", klog.KObj(nodesMap[nodeName]), "usage", nodesUsageMap[nodeName], "usagePercentage", resourceUsagePercentages(nodesUsageMap[nodeName], nodesMap[nodeName], true))
+			klog.InfoS(
+				"Node is appropriately utilized",
+				"node", klog.KObj(nodesMap[nodeName]),
+				"usage", nodesUsageMap[nodeName],
+				"usagePercentage", normalizer.Round(usage[nodeName]),
+			)
 		}
 	}
 
@@ -275,7 +294,7 @@ func (l *LowNodeUtilization) Balance(ctx context.Context, nodes []*v1.Node) *fra
 		l.handle.Evictor(),
 		evictions.EvictOptions{StrategyName: LowNodeUtilizationPluginName},
 		l.podFilter,
-		l.resourceNames,
+		l.extendedResourceNames,
 		continueEvictionCond,
 		l.usageClient,
 		nodeLimit,
@@ -283,34 +302,3 @@ func (l *LowNodeUtilization) Balance(ctx context.Context, nodes []*v1.Node) *fra
 
 	return nil
 }
-
-func setDefaultForLNUThresholds(thresholds, targetThresholds api.ResourceThresholds, useDeviationThresholds bool) {
-	// check if Pods/CPU/Mem are set, if not, set them to 100
-	if _, ok := thresholds[v1.ResourcePods]; !ok {
-		if useDeviationThresholds {
-			thresholds[v1.ResourcePods] = MinResourcePercentage
-			targetThresholds[v1.ResourcePods] = MinResourcePercentage
-		} else {
-			thresholds[v1.ResourcePods] = MaxResourcePercentage
-			targetThresholds[v1.ResourcePods] = MaxResourcePercentage
-		}
-	}
-	if _, ok := thresholds[v1.ResourceCPU]; !ok {
-		if useDeviationThresholds {
-			thresholds[v1.ResourceCPU] = MinResourcePercentage
-			targetThresholds[v1.ResourceCPU] = MinResourcePercentage
-		} else {
-			thresholds[v1.ResourceCPU] = MaxResourcePercentage
-			targetThresholds[v1.ResourceCPU] = MaxResourcePercentage
-		}
-	}
-	if _, ok := thresholds[v1.ResourceMemory]; !ok {
-		if useDeviationThresholds {
-			thresholds[v1.ResourceMemory] = MinResourcePercentage
-			targetThresholds[v1.ResourceMemory] = MinResourcePercentage
-		} else {
-			thresholds[v1.ResourceMemory] = MaxResourcePercentage
-			targetThresholds[v1.ResourceMemory] = MaxResourcePercentage
-		}
-	}
-}

pkg/framework/plugins/nodeutilization/lownodeutilization_test.go

@@ -1022,6 +1022,79 @@ func TestLowNodeUtilization(t *testing.T) {
 			expectedPodsWithMetricsEvicted: 2,
 			evictedPods:                    []string{},
 		},
+		{
+			name: "deviation thresholds and overevicting memory",
+			thresholds: api.ResourceThresholds{
+				v1.ResourceCPU:  5,
+				v1.ResourcePods: 5,
+			},
+			targetThresholds: api.ResourceThresholds{
+				v1.ResourceCPU:  5,
+				v1.ResourcePods: 5,
+			},
+			useDeviationThresholds: true,
+			nodes: []*v1.Node{
+				test.BuildTestNode(n1NodeName, 4000, 3000, 10, nil),
+				test.BuildTestNode(n2NodeName, 4000, 3000, 10, nil),
+				test.BuildTestNode(n3NodeName, 4000, 3000, 10, test.SetNodeUnschedulable),
+			},
+			// totalcpuusage = 3600m, avgcpuusage = 3600/12000 = 0.3 => 30%
+			// totalpodsusage = 9, avgpodsusage = 9/30 = 0.3 => 30%
+			// n1 and n2 are fully memory utilized
+			pods: []*v1.Pod{
+				test.BuildTestPod("p1", 400, 375, n1NodeName, test.SetRSOwnerRef),
+				test.BuildTestPod("p2", 400, 375, n1NodeName, test.SetRSOwnerRef),
+				test.BuildTestPod("p3", 400, 375, n1NodeName, test.SetRSOwnerRef),
+				test.BuildTestPod("p4", 400, 375, n1NodeName, test.SetRSOwnerRef),
+				test.BuildTestPod("p5", 400, 375, n1NodeName, test.SetRSOwnerRef),
+				// These won't be evicted.
+				test.BuildTestPod("p6", 400, 375, n1NodeName, test.SetDSOwnerRef),
+				test.BuildTestPod("p7", 400, 375, n1NodeName, func(pod *v1.Pod) {
+					// A pod with local storage.
+					test.SetNormalOwnerRef(pod)
+					pod.Spec.Volumes = []v1.Volume{
+						{
+							Name: "sample",
+							VolumeSource: v1.VolumeSource{
+								HostPath: &v1.HostPathVolumeSource{Path: "somePath"},
+								EmptyDir: &v1.EmptyDirVolumeSource{
+									SizeLimit: resource.NewQuantity(int64(10), resource.BinarySI),
+								},
+							},
+						},
+					}
+					// A Mirror Pod.
+					pod.Annotations = test.GetMirrorPodAnnotation()
+				}),
+				test.BuildTestPod("p8", 400, 375, n1NodeName, func(pod *v1.Pod) {
+					// A Critical Pod.
+					test.SetNormalOwnerRef(pod)
+					pod.Namespace = "kube-system"
+					priority := utils.SystemCriticalPriority
+					pod.Spec.Priority = &priority
+				}),
+				test.BuildTestPod("p9", 400, 3000, n2NodeName, test.SetRSOwnerRef),
+			},
+			nodemetricses: []*v1beta1.NodeMetrics{
+				test.BuildNodeMetrics(n1NodeName, 4000, 3000),
+				test.BuildNodeMetrics(n2NodeName, 4000, 3000),
+				test.BuildNodeMetrics(n3NodeName, 4000, 3000),
+			},
+			podmetricses: []*v1beta1.PodMetrics{
+				test.BuildPodMetrics("p1", 400, 375),
+				test.BuildPodMetrics("p2", 400, 375),
+				test.BuildPodMetrics("p3", 400, 375),
+				test.BuildPodMetrics("p4", 400, 375),
+				test.BuildPodMetrics("p5", 400, 375),
+				test.BuildPodMetrics("p6", 400, 375),
+				test.BuildPodMetrics("p7", 400, 375),
+				test.BuildPodMetrics("p8", 400, 375),
+				test.BuildPodMetrics("p9", 400, 3000),
+			},
+			expectedPodsEvicted:            0,
+			expectedPodsWithMetricsEvicted: 0,
+			evictedPods:                    []string{},
+		},
 		{
 			name: "without priorities different evictions for requested and actual resources",
 			thresholds: api.ResourceThresholds{
@@ -1612,6 +1685,43 @@ func TestLowNodeUtilizationWithPrometheusMetrics(t *testing.T) {
 			},
 			expectedPodsEvicted: 2,
 		},
+		{
+			name: "with instance:node_cpu:rate:sum query and deviation thresholds",
+			args: &LowNodeUtilizationArgs{
+				UseDeviationThresholds: true,
+				Thresholds:             api.ResourceThresholds{MetricResource: 10},
+				TargetThresholds:       api.ResourceThresholds{MetricResource: 10},
+				MetricsUtilization: &MetricsUtilization{
+					Source: api.PrometheusMetrics,
+					Prometheus: &Prometheus{
+						Query: "instance:node_cpu:rate:sum",
+					},
+				},
+			},
+			samples: model.Vector{
+				sample("instance:node_cpu:rate:sum", n1NodeName, 1),
+				sample("instance:node_cpu:rate:sum", n2NodeName, 0.5),
+				sample("instance:node_cpu:rate:sum", n3NodeName, 0),
+			},
+			nodes: []*v1.Node{
+				test.BuildTestNode(n1NodeName, 4000, 3000, 9, nil),
+				test.BuildTestNode(n2NodeName, 4000, 3000, 10, nil),
+				test.BuildTestNode(n3NodeName, 4000, 3000, 10, nil),
+			},
+			pods: []*v1.Pod{
+				test.BuildTestPod("p1", 400, 0, n1NodeName, test.SetRSOwnerRef),
+				test.BuildTestPod("p2", 400, 0, n1NodeName, test.SetRSOwnerRef),
+				test.BuildTestPod("p3", 400, 0, n1NodeName, test.SetRSOwnerRef),
+				test.BuildTestPod("p4", 400, 0, n1NodeName, test.SetRSOwnerRef),
+				test.BuildTestPod("p5", 400, 0, n1NodeName, test.SetRSOwnerRef),
+				// These won't be evicted.
+				test.BuildTestPod("p6", 400, 0, n1NodeName, test.SetDSOwnerRef),
+				test.BuildTestPod("p7", 400, 0, n1NodeName, withLocalStorage),
+				test.BuildTestPod("p8", 400, 0, n1NodeName, withCriticalPod),
+				test.BuildTestPod("p9", 400, 0, n2NodeName, test.SetRSOwnerRef),
+			},
+			expectedPodsEvicted: 1,
+		},
 	}
 
 	for _, tc := range testCases {

pkg/framework/plugins/nodeutilization/nodeutilization.go

@@ -18,7 +18,7 @@ package nodeutilization
 
 import (
 	"context"
-	"math"
+	"maps"
 	"slices"
 	"sort"
 
@@ -28,9 +28,11 @@ import (
 	"k8s.io/apimachinery/pkg/api/resource"
 	"k8s.io/apimachinery/pkg/util/sets"
 	"k8s.io/klog/v2"
+	"k8s.io/utils/ptr"
 	"sigs.k8s.io/descheduler/pkg/descheduler/evictions"
 	nodeutil "sigs.k8s.io/descheduler/pkg/descheduler/node"
 	podutil "sigs.k8s.io/descheduler/pkg/descheduler/pod"
+	"sigs.k8s.io/descheduler/pkg/framework/plugins/nodeutilization/normalizer"
 	frameworktypes "sigs.k8s.io/descheduler/pkg/framework/types"
 	"sigs.k8s.io/descheduler/pkg/utils"
 )
@@ -85,84 +87,6 @@ const (
 	MaxResourcePercentage = 100
 )
 
-func normalizePercentage(percent api.Percentage) api.Percentage {
-	if percent > MaxResourcePercentage {
-		return MaxResourcePercentage
-	}
-	if percent < MinResourcePercentage {
-		return MinResourcePercentage
-	}
-	return percent
-}
-
-func nodeCapacity(node *v1.Node, nodeUsage api.ReferencedResourceList) v1.ResourceList {
-	capacity := node.Status.Capacity
-	if len(node.Status.Allocatable) > 0 {
-		capacity = node.Status.Allocatable
-	}
-	// the usage captures the metrics resource
-	if _, ok := nodeUsage[MetricResource]; ok {
-		// Make ResourceMetrics 100% => 100 points
-		capacity[MetricResource] = *resource.NewQuantity(int64(100), resource.DecimalSI)
-	}
-	return capacity
-}
-
-func getNodeThresholdsFromAverageNodeUsage(
-	nodes []*v1.Node,
-	usageClient usageClient,
-	lowSpan, highSpan api.ResourceThresholds,
-) (map[string][]api.ResourceThresholds, api.ResourceThresholds) {
-	total := api.ResourceThresholds{}
-	average := api.ResourceThresholds{}
-	numberOfNodes := len(nodes)
-	for _, node := range nodes {
-		usage := usageClient.nodeUtilization(node.Name)
-		nodeCapacity := nodeCapacity(node, usage)
-		for resource, value := range usage {
-			nodeCapacityValue := nodeCapacity[resource]
-			if resource == v1.ResourceCPU {
-				total[resource] += api.Percentage(value.MilliValue()) / api.Percentage(nodeCapacityValue.MilliValue()) * 100.0
-			} else {
-				total[resource] += api.Percentage(value.Value()) / api.Percentage(nodeCapacityValue.Value()) * 100.0
-			}
-		}
-	}
-	lowThreshold, highThreshold := api.ResourceThresholds{}, api.ResourceThresholds{}
-	for resource, value := range total {
-		average[resource] = value / api.Percentage(numberOfNodes)
-		// If either of the spans are 0, ignore the resource. I.e. 0%:5% is invalid.
-		// Any zero span signifies a resource is either not set or is to be ignored.
-		if lowSpan[resource] == MinResourcePercentage || highSpan[resource] == MinResourcePercentage {
-			lowThreshold[resource] = 1
-			highThreshold[resource] = 1
-		} else {
-			lowThreshold[resource] = normalizePercentage(average[resource] - lowSpan[resource])
-			highThreshold[resource] = normalizePercentage(average[resource] + highSpan[resource])
-		}
-	}
-
-	nodeThresholds := make(map[string][]api.ResourceThresholds)
-	for _, node := range nodes {
-		nodeThresholds[node.Name] = []api.ResourceThresholds{
-			lowThreshold,
-			highThreshold,
-		}
-	}
-	return nodeThresholds, average
-}
-
-func getStaticNodeThresholds(
-	nodes []*v1.Node,
-	thresholdsList ...api.ResourceThresholds,
-) map[string][]api.ResourceThresholds {
-	nodeThresholds := make(map[string][]api.ResourceThresholds)
-	for _, node := range nodes {
-		nodeThresholds[node.Name] = append([]api.ResourceThresholds{}, slices.Clone(thresholdsList)...)
-	}
-	return nodeThresholds
-}
-
 // getNodeUsageSnapshot separates the snapshot into easily accesible
 // data chunks so the node usage can be processed separately.
 func getNodeUsageSnapshot(
@@ -187,7 +111,7 @@ func getNodeUsageSnapshot(
 	return nodesMap, nodesUsageMap, podListMap
 }
 
-func resourceThreshold(nodeCapacity v1.ResourceList, resourceName v1.ResourceName, threshold api.Percentage) *resource.Quantity {
+func resourceThreshold(nodeCapacity api.ReferencedResourceList, resourceName v1.ResourceName, threshold api.Percentage) *resource.Quantity {
 	defaultFormat := resource.DecimalSI
 	if resourceName == v1.ResourceMemory {
 		defaultFormat = resource.BinarySI
@@ -200,7 +124,10 @@ func resourceThreshold(nodeCapacity v1.ResourceList, resourceName v1.ResourceNam
 		return int64(float64(threshold) * 0.01 * float64(resourceNodeCapacity))
 	}
 
-	resourceCapacityQuantity := nodeCapacity.Name(resourceName, defaultFormat)
+	resourceCapacityQuantity := &resource.Quantity{Format: defaultFormat}
+	if _, ok := nodeCapacity[resourceName]; ok {
+		resourceCapacityQuantity = nodeCapacity[resourceName]
+	}
 
 	if resourceName == v1.ResourceCPU {
 		return resource.NewMilliQuantity(resourceCapacityFraction(resourceCapacityQuantity.MilliValue()), defaultFormat)
@@ -208,47 +135,17 @@ func resourceThreshold(nodeCapacity v1.ResourceList, resourceName v1.ResourceNam
 	return resource.NewQuantity(resourceCapacityFraction(resourceCapacityQuantity.Value()), defaultFormat)
 }
 
-func resourceThresholdsToNodeUsage(resourceThresholds api.ResourceThresholds, node *v1.Node) api.ReferencedResourceList {
+func resourceThresholdsToNodeUsage(resourceThresholds api.ResourceThresholds, capacity api.ReferencedResourceList, resourceNames []v1.ResourceName) api.ReferencedResourceList {
 	nodeUsage := make(api.ReferencedResourceList)
-
-	nodeCapacity := node.Status.Capacity
-	if len(node.Status.Allocatable) > 0 {
-		nodeCapacity = node.Status.Allocatable
-	}
 	for resourceName, threshold := range resourceThresholds {
-		nodeUsage[resourceName] = resourceThreshold(nodeCapacity, resourceName, threshold)
+		nodeUsage[resourceName] = resourceThreshold(capacity, resourceName, threshold)
 	}
-
-	return nodeUsage
-}
-
-func roundTo2Decimals(percentage float64) float64 {
-	return math.Round(percentage*100) / 100
-}
-
-func resourceUsagePercentages(nodeUsage api.ReferencedResourceList, node *v1.Node, round bool) api.ResourceThresholds {
-	nodeCapacity := nodeCapacity(node, nodeUsage)
-
-	resourceUsagePercentage := api.ResourceThresholds{}
-	for resourceName, resourceUsage := range nodeUsage {
-		cap := nodeCapacity[resourceName]
-		if !cap.IsZero() {
-			value := 100 * float64(resourceUsage.MilliValue()) / float64(cap.MilliValue())
-			if round {
-				value = roundTo2Decimals(float64(value))
-			}
-			resourceUsagePercentage[resourceName] = api.Percentage(value)
+	for _, resourceName := range resourceNames {
+		if _, exists := nodeUsage[resourceName]; !exists {
+			nodeUsage[resourceName] = capacity[resourceName]
 		}
 	}
-	return resourceUsagePercentage
-}
-
-func nodeUsageToResourceThresholds(nodeUsage map[string]api.ReferencedResourceList, nodes map[string]*v1.Node) map[string]api.ResourceThresholds {
-	resourceThresholds := make(map[string]api.ResourceThresholds)
-	for nodeName, node := range nodes {
-		resourceThresholds[nodeName] = resourceUsagePercentages(nodeUsage[nodeName], node, false)
-	}
-	return resourceThresholds
+	return nodeUsage
 }
 
 type classifierFnc func(nodeName string, value, threshold api.ResourceThresholds) bool
@@ -503,8 +400,8 @@ func isNodeAboveTargetUtilization(usage NodeUsage, threshold api.ReferencedResou
 // isNodeAboveThreshold checks if a node is over a threshold
 // At least one resource has to be above the threshold
 func isNodeAboveThreshold(usage, threshold api.ResourceThresholds) bool {
-	for name, resourceValue := range usage {
-		if threshold[name] < resourceValue {
+	for name := range threshold {
+		if threshold[name] < usage[name] {
 			return true
 		}
 	}
@@ -514,8 +411,8 @@ func isNodeAboveThreshold(usage, threshold api.ResourceThresholds) bool {
 // isNodeBelowThreshold checks if a node is under a threshold
 // All resources have to be below the threshold
 func isNodeBelowThreshold(usage, threshold api.ResourceThresholds) bool {
-	for name, resourceValue := range usage {
-		if threshold[name] < resourceValue {
+	for name := range threshold {
+		if threshold[name] < usage[name] {
 			return false
 		}
 	}
@@ -544,3 +441,155 @@ func classifyPods(pods []*v1.Pod, filter func(pod *v1.Pod) bool) ([]*v1.Pod, []*
 
 	return nonRemovablePods, removablePods
 }
+
+// assessNodesUsagesAndStaticThresholds converts the raw usage data into
+// percentage. Returns the usage (pct) and the thresholds (pct) for each
+// node.
+func assessNodesUsagesAndStaticThresholds(
+	rawUsages, rawCapacities map[string]api.ReferencedResourceList,
+	lowSpan, highSpan api.ResourceThresholds,
+) (map[string]api.ResourceThresholds, map[string][]api.ResourceThresholds) {
+	// first we normalize the node usage from the raw data (Mi, Gi, etc)
+	// into api.Percentage values.
+	usage := normalizer.Normalize(
+		rawUsages, rawCapacities, ResourceUsageToResourceThreshold,
+	)
+
+	// we are not taking the average and applying deviations to it we can
+	// simply replicate the same threshold across all nodes and return.
+	thresholds := normalizer.Replicate(
+		slices.Collect(maps.Keys(usage)),
+		[]api.ResourceThresholds{lowSpan, highSpan},
+	)
+	return usage, thresholds
+}
+
+// assessNodesUsagesAndRelativeThresholds converts the raw usage data into
+// percentage. Thresholds are calculated based on the average usage. Returns
+// the usage (pct) and the thresholds (pct) for each node.
+func assessNodesUsagesAndRelativeThresholds(
+	rawUsages, rawCapacities map[string]api.ReferencedResourceList,
+	lowSpan, highSpan api.ResourceThresholds,
+) (map[string]api.ResourceThresholds, map[string][]api.ResourceThresholds) {
+	// first we normalize the node usage from the raw data (Mi, Gi, etc)
+	// into api.Percentage values.
+	usage := normalizer.Normalize(
+		rawUsages, rawCapacities, ResourceUsageToResourceThreshold,
+	)
+
+	// calculate the average usage and then deviate it according to the
+	// user provided thresholds.
+	average := normalizer.Average(usage)
+
+	// calculate the average usage and then deviate it according to the
+	// user provided thresholds. We also ensure that the value after the
+	// deviation is at least 1%. this call also replicates the thresholds
+	// across all nodes.
+	thresholds := normalizer.Replicate(
+		slices.Collect(maps.Keys(usage)),
+		normalizer.Map(
+			[]api.ResourceThresholds{
+				normalizer.Sum(average, normalizer.Negate(lowSpan)),
+				normalizer.Sum(average, highSpan),
+			},
+			func(thresholds api.ResourceThresholds) api.ResourceThresholds {
+				return normalizer.Clamp(thresholds, 0, 100)
+			},
+		),
+	)
+
+	return usage, thresholds
+}
+
+// referencedResourceListForNodesCapacity returns a ReferencedResourceList for
+// the capacity of a list of nodes. If allocatable resources are present, they
+// are used instead of capacity.
+func referencedResourceListForNodesCapacity(nodes []*v1.Node) map[string]api.ReferencedResourceList {
+	capacities := map[string]api.ReferencedResourceList{}
+	for _, node := range nodes {
+		capacity := node.Status.Capacity
+		if len(node.Status.Allocatable) > 0 {
+			capacity = node.Status.Allocatable
+		}
+
+		referenced := api.ReferencedResourceList{}
+		for name, quantity := range capacity {
+			referenced[name] = ptr.To(quantity)
+		}
+
+		// XXX the descheduler also manages monitoring queries that are
+		// supposed to return a value representing a percentage of the
+		// resource usage. In this case we need to provide a value for
+		// the MetricResource, which is not present in the node capacity.
+		referenced[MetricResource] = resource.NewQuantity(
+			100, resource.DecimalSI,
+		)
+
+		capacities[node.Name] = referenced
+	}
+	return capacities
+}
+
+// ResourceUsage2ResourceThreshold is an implementation of a Normalizer that
+// converts a set of resource usages and totals into percentage. This function
+// operates on Quantity Value() for all the resources except CPU, where it uses
+// MilliValue().
+func ResourceUsageToResourceThreshold(
+	usages, totals api.ReferencedResourceList,
+) api.ResourceThresholds {
+	result := api.ResourceThresholds{}
+	for rname, value := range usages {
+		if value == nil || totals[rname] == nil {
+			continue
+		}
+
+		total := totals[rname]
+		used, capacity := value.Value(), total.Value()
+		if rname == v1.ResourceCPU {
+			used, capacity = value.MilliValue(), total.MilliValue()
+		}
+
+		var percent float64
+		if capacity > 0 {
+			percent = float64(used) / float64(capacity) * 100
+		}
+
+		result[rname] = api.Percentage(percent)
+	}
+	return result
+}
+
+// uniquifyResourceNames returns a slice of resource names with duplicates
+// removed.
+func uniquifyResourceNames(resourceNames []v1.ResourceName) []v1.ResourceName {
+	resourceNamesMap := map[v1.ResourceName]bool{
+		v1.ResourceCPU:    true,
+		v1.ResourceMemory: true,
+		v1.ResourcePods:   true,
+	}
+	for _, resourceName := range resourceNames {
+		resourceNamesMap[resourceName] = true
+	}
+	extendedResourceNames := []v1.ResourceName{}
+	for resourceName := range resourceNamesMap {
+		extendedResourceNames = append(extendedResourceNames, resourceName)
+	}
+	return extendedResourceNames
+}
+
+// filterResourceNamesFromNodeUsage removes from the node usage slice all keys
+// that are not present in the resourceNames slice.
+func filterResourceNamesFromNodeUsage(
+	nodeUsage map[string]api.ReferencedResourceList, resourceNames []v1.ResourceName,
+) map[string]api.ReferencedResourceList {
+	newNodeUsage := make(map[string]api.ReferencedResourceList)
+	for nodeName, usage := range nodeUsage {
+		newNodeUsage[nodeName] = api.ReferencedResourceList{}
+		for _, resourceName := range resourceNames {
+			if _, exists := usage[resourceName]; exists {
+				newNodeUsage[nodeName][resourceName] = usage[resourceName]
+			}
+		}
+	}
+	return newNodeUsage
+}

pkg/framework/plugins/nodeutilization/nodeutilization_test.go

@@ -17,7 +17,7 @@ limitations under the License.
 package nodeutilization
 
 import (
-	"math"
+	"reflect"
 	"testing"
 
 	v1 "k8s.io/api/core/v1"
@@ -56,45 +56,6 @@ var (
 	extendedResource = v1.ResourceName("example.com/foo")
 )
 
-func TestResourceUsagePercentages(t *testing.T) {
-	resourceUsagePercentage := resourceUsagePercentages(
-		api.ReferencedResourceList{
-			v1.ResourceCPU:    resource.NewMilliQuantity(1220, resource.DecimalSI),
-			v1.ResourceMemory: resource.NewQuantity(3038982964, resource.BinarySI),
-			v1.ResourcePods:   resource.NewQuantity(11, resource.BinarySI),
-		},
-		&v1.Node{
-			Status: v1.NodeStatus{
-				Capacity: v1.ResourceList{
-					v1.ResourceCPU:    *resource.NewMilliQuantity(2000, resource.DecimalSI),
-					v1.ResourceMemory: *resource.NewQuantity(3977868*1024, resource.BinarySI),
-					v1.ResourcePods:   *resource.NewQuantity(29, resource.BinarySI),
-				},
-				Allocatable: v1.ResourceList{
-					v1.ResourceCPU:    *resource.NewMilliQuantity(1930, resource.DecimalSI),
-					v1.ResourceMemory: *resource.NewQuantity(3287692*1024, resource.BinarySI),
-					v1.ResourcePods:   *resource.NewQuantity(29, resource.BinarySI),
-				},
-			},
-		},
-		true,
-	)
-
-	expectedUsageInIntPercentage := map[v1.ResourceName]float64{
-		v1.ResourceCPU:    63,
-		v1.ResourceMemory: 90,
-		v1.ResourcePods:   37,
-	}
-
-	for resourceName, percentage := range expectedUsageInIntPercentage {
-		if math.Floor(float64(resourceUsagePercentage[resourceName])) != percentage {
-			t.Errorf("Incorrect percentange computation, expected %v, got math.Floor(%v) instead", percentage, resourceUsagePercentage[resourceName])
-		}
-	}
-
-	t.Logf("resourceUsagePercentage: %#v\n", resourceUsagePercentage)
-}
-
 func TestSortNodesByUsage(t *testing.T) {
 	tests := []struct {
 		name                  string
@@ -173,3 +134,83 @@ func TestSortNodesByUsage(t *testing.T) {
 		})
 	}
 }
+
+func TestResourceUsageToResourceThreshold(t *testing.T) {
+	for _, tt := range []struct {
+		name     string
+		usage    api.ReferencedResourceList
+		capacity api.ReferencedResourceList
+		expected api.ResourceThresholds
+	}{
+		{
+			name: "10 percent",
+			usage: api.ReferencedResourceList{
+				v1.ResourceCPU: resource.NewMilliQuantity(100, resource.DecimalSI),
+			},
+			capacity: api.ReferencedResourceList{
+				v1.ResourceCPU: resource.NewMilliQuantity(1000, resource.DecimalSI),
+			},
+			expected: api.ResourceThresholds{v1.ResourceCPU: 10},
+		},
+		{
+			name: "zeroed out capacity",
+			usage: api.ReferencedResourceList{
+				v1.ResourceCPU: resource.NewMilliQuantity(100, resource.DecimalSI),
+			},
+			capacity: api.ReferencedResourceList{
+				v1.ResourceCPU: resource.NewMilliQuantity(0, resource.DecimalSI),
+			},
+			expected: api.ResourceThresholds{v1.ResourceCPU: 0},
+		},
+		{
+			name: "non existing usage",
+			usage: api.ReferencedResourceList{
+				"does-not-exist": resource.NewMilliQuantity(100, resource.DecimalSI),
+			},
+			capacity: api.ReferencedResourceList{
+				v1.ResourceCPU:    resource.NewMilliQuantity(100, resource.DecimalSI),
+				v1.ResourceMemory: resource.NewMilliQuantity(100, resource.DecimalSI),
+			},
+			expected: api.ResourceThresholds{},
+		},
+		{
+			name: "existing and non existing usage",
+			usage: api.ReferencedResourceList{
+				"does-not-exist": resource.NewMilliQuantity(100, resource.DecimalSI),
+				v1.ResourceCPU:   resource.NewMilliQuantity(200, resource.DecimalSI),
+			},
+			capacity: api.ReferencedResourceList{
+				v1.ResourceCPU:    resource.NewMilliQuantity(1000, resource.DecimalSI),
+				v1.ResourceMemory: resource.NewMilliQuantity(1000, resource.DecimalSI),
+			},
+			expected: api.ResourceThresholds{v1.ResourceCPU: 20},
+		},
+		{
+			name: "nil usage",
+			usage: api.ReferencedResourceList{
+				v1.ResourceCPU: nil,
+			},
+			capacity: api.ReferencedResourceList{
+				v1.ResourceCPU: resource.NewMilliQuantity(1000, resource.DecimalSI),
+			},
+			expected: api.ResourceThresholds{},
+		},
+		{
+			name: "nil capacity",
+			usage: api.ReferencedResourceList{
+				v1.ResourceCPU: resource.NewMilliQuantity(100, resource.DecimalSI),
+			},
+			capacity: api.ReferencedResourceList{
+				v1.ResourceCPU: nil,
+			},
+			expected: api.ResourceThresholds{},
+		},
+	} {
+		t.Run(tt.name, func(t *testing.T) {
+			result := ResourceUsageToResourceThreshold(tt.usage, tt.capacity)
+			if !reflect.DeepEqual(result, tt.expected) {
+				t.Errorf("Expected %v, got %v", tt.expected, result)
+			}
+		})
+	}
+}

pkg/framework/plugins/nodeutilization/normalizer/normalizer.go

@@ -0,0 +1,142 @@
+/*
+Copyright 2025 The Kubernetes Authors.
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+	http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package normalizer
+
+import (
+	"math"
+
+	"golang.org/x/exp/constraints"
+)
+
+// Normalizer is a function that receives two values of the same type and
+// return an object of a different type. An usage case can be a function
+// that converts a memory usage from mb to % (the first argument would be
+// the memory usage in mb and the second argument would be the total memory
+// available in mb).
+type Normalizer[V, N any] func(V, V) N
+
+// Values is a map of values indexed by a comparable key. An example of this
+// can be a list of resources indexed by a node name.
+type Values[K comparable, V any] map[K]V
+
+// Number is an interface that represents a number. Represents things we
+// can do math operations on.
+type Number interface {
+	constraints.Integer | constraints.Float
+}
+
+// Normalize uses a Normalizer function to normalize a set of values. For
+// example one may want to convert a set of memory usages from mb to %.
+// This function receives a set of usages, a set of totals, and a Normalizer
+// function. The function will return a map with the normalized values.
+func Normalize[K comparable, V, N any](usages, totals Values[K, V], fn Normalizer[V, N]) map[K]N {
+	result := Values[K, N]{}
+	for key, value := range usages {
+		total, ok := totals[key]
+		if !ok {
+			continue
+		}
+		result[key] = fn(value, total)
+	}
+	return result
+}
+
+// Replicate replicates the provide value for each key in the provided slice.
+// Returns a map with the keys and the provided value.
+func Replicate[K comparable, V any](keys []K, value V) map[K]V {
+	result := map[K]V{}
+	for _, key := range keys {
+		result[key] = value
+	}
+	return result
+}
+
+// Clamp imposes minimum and maximum limits on a set of values. The function
+// will return a set of values where each value is between the minimum and
+// maximum values (included). Values below minimum are rounded up to the
+// minimum value, and values above maximum are rounded down to the maximum
+// value.
+func Clamp[K comparable, N Number, V ~map[K]N](values V, minimum, maximum N) V {
+	result := V{}
+	for key := range values {
+		value := values[key]
+		value = N(math.Max(float64(value), float64(minimum)))
+		value = N(math.Min(float64(value), float64(maximum)))
+		result[key] = value
+	}
+	return result
+}
+
+// Map applies a function to each element of a map of values. Returns a new
+// slice with the results of applying the function to each element.
+func Map[K comparable, N Number, V ~map[K]N](items []V, fn func(V) V) []V {
+	result := []V{}
+	for _, item := range items {
+		result = append(result, fn(item))
+	}
+	return result
+}
+
+// Negate converts the values of a map to their negated values.
+func Negate[K comparable, N Number, V ~map[K]N](values V) V {
+	result := V{}
+	for key, value := range values {
+		result[key] = -value
+	}
+	return result
+}
+
+// Round rounds the values of a map to the nearest integer. Calls math.Round on
+// each value of the map.
+func Round[K comparable, N Number, V ~map[K]N](values V) V {
+	result := V{}
+	for key, value := range values {
+		result[key] = N(math.Round(float64(value)))
+	}
+	return result
+}
+
+// Sum sums up the values of two maps. Values are expected to be of Number
+// type. Original values are preserved. If a key is present in one map but
+// not in the other, the key is ignored.
+func Sum[K comparable, N Number, V ~map[K]N](mapA, mapB V) V {
+	result := V{}
+	for name, value := range mapA {
+		result[name] = value + mapB[name]
+	}
+	return result
+}
+
+// Average calculates the average of a set of values. This function receives
+// a map of values and returns the average of all the values. Average expects
+// the values to represent the same unit of measure. You can use this function
+// after Normalizing the values.
+func Average[J, K comparable, N Number, V ~map[J]N](values map[K]V) V {
+	counter := map[J]int{}
+	result := V{}
+	for _, imap := range values {
+		for name, value := range imap {
+			result[name] += value
+			counter[name]++
+		}
+	}
+
+	for name := range result {
+		result[name] /= N(counter[name])
+	}
+
+	return result
+}

pkg/framework/plugins/nodeutilization/normalizer/normalizer_test.go

@@ -0,0 +1,649 @@
+/*
+Copyright 2025 The Kubernetes Authors.
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+	http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package normalizer
+
+import (
+	"fmt"
+	"math"
+	"reflect"
+	"testing"
+
+	v1 "k8s.io/api/core/v1"
+	"k8s.io/apimachinery/pkg/api/resource"
+	"sigs.k8s.io/descheduler/pkg/api"
+)
+
+func ResourceListUsageNormalizer(usages, totals v1.ResourceList) api.ResourceThresholds {
+	result := api.ResourceThresholds{}
+	for rname, value := range usages {
+		total, ok := totals[rname]
+		if !ok {
+			continue
+		}
+
+		used, avail := value.Value(), total.Value()
+		if rname == v1.ResourceCPU {
+			used, avail = value.MilliValue(), total.MilliValue()
+		}
+
+		pct := math.Max(math.Min(float64(used)/float64(avail)*100, 100), 0)
+		result[rname] = api.Percentage(pct)
+	}
+	return result
+}
+
+func TestNormalizeSimple(t *testing.T) {
+	for _, tt := range []struct {
+		name       string
+		usages     map[string]float64
+		totals     map[string]float64
+		expected   map[string]float64
+		normalizer Normalizer[float64, float64]
+	}{
+		{
+			name:     "single normalization",
+			usages:   map[string]float64{"cpu": 1},
+			totals:   map[string]float64{"cpu": 2},
+			expected: map[string]float64{"cpu": 0.5},
+			normalizer: func(usage, total float64) float64 {
+				return usage / total
+			},
+		},
+		{
+			name: "multiple normalizations",
+			usages: map[string]float64{
+				"cpu": 1,
+				"mem": 6,
+			},
+			totals: map[string]float64{
+				"cpu": 2,
+				"mem": 10,
+			},
+			expected: map[string]float64{
+				"cpu": 0.5,
+				"mem": 0.6,
+			},
+			normalizer: func(usage, total float64) float64 {
+				return usage / total
+			},
+		},
+		{
+			name: "missing totals for a key",
+			usages: map[string]float64{
+				"cpu": 1,
+				"mem": 6,
+			},
+			totals: map[string]float64{
+				"cpu": 2,
+			},
+			expected: map[string]float64{
+				"cpu": 0.5,
+			},
+			normalizer: func(usage, total float64) float64 {
+				return usage / total
+			},
+		},
+	} {
+		t.Run(tt.name, func(t *testing.T) {
+			result := Normalize(tt.usages, tt.totals, tt.normalizer)
+			if !reflect.DeepEqual(result, tt.expected) {
+				t.Fatalf("unexpected result: %v", result)
+			}
+		})
+	}
+}
+
+func TestNormalize(t *testing.T) {
+	for _, tt := range []struct {
+		name       string
+		usages     map[string]v1.ResourceList
+		totals     map[string]v1.ResourceList
+		expected   map[string]api.ResourceThresholds
+		normalizer Normalizer[v1.ResourceList, api.ResourceThresholds]
+	}{
+		{
+			name: "single normalization",
+			usages: map[string]v1.ResourceList{
+				"node1": {v1.ResourceCPU: resource.MustParse("1")},
+			},
+			totals: map[string]v1.ResourceList{
+				"node1": {v1.ResourceCPU: resource.MustParse("2")},
+			},
+			expected: map[string]api.ResourceThresholds{
+				"node1": {v1.ResourceCPU: 50},
+			},
+			normalizer: ResourceListUsageNormalizer,
+		},
+		{
+			name: "multiple normalization",
+			usages: map[string]v1.ResourceList{
+				"node1": {
+					v1.ResourceCPU:    resource.MustParse("1"),
+					v1.ResourceMemory: resource.MustParse("6"),
+					v1.ResourcePods:   resource.MustParse("2"),
+				},
+				"node2": {
+					v1.ResourceCPU:    resource.MustParse("10"),
+					v1.ResourceMemory: resource.MustParse("20"),
+					v1.ResourcePods:   resource.MustParse("30"),
+				},
+			},
+			totals: map[string]v1.ResourceList{
+				"node1": {
+					v1.ResourceCPU:    resource.MustParse("2"),
+					v1.ResourceMemory: resource.MustParse("6"),
+					v1.ResourcePods:   resource.MustParse("100"),
+				},
+				"node2": {
+					v1.ResourceCPU:    resource.MustParse("100"),
+					v1.ResourceMemory: resource.MustParse("100"),
+					v1.ResourcePods:   resource.MustParse("100"),
+				},
+			},
+			expected: map[string]api.ResourceThresholds{
+				"node1": {
+					v1.ResourceCPU:    50,
+					v1.ResourceMemory: 100,
+					v1.ResourcePods:   2,
+				},
+				"node2": {
+					v1.ResourceCPU:    10,
+					v1.ResourceMemory: 20,
+					v1.ResourcePods:   30,
+				},
+			},
+			normalizer: ResourceListUsageNormalizer,
+		},
+		{
+			name: "multiple normalization with over 100% usage",
+			usages: map[string]v1.ResourceList{
+				"node1": {
+					v1.ResourceCPU:    resource.MustParse("120"),
+					v1.ResourceMemory: resource.MustParse("130"),
+					v1.ResourcePods:   resource.MustParse("140"),
+				},
+				"node2": {
+					v1.ResourceCPU:    resource.MustParse("150"),
+					v1.ResourceMemory: resource.MustParse("160"),
+					v1.ResourcePods:   resource.MustParse("170"),
+				},
+			},
+			totals: Replicate(
+				[]string{"node1", "node2"},
+				v1.ResourceList{
+					v1.ResourceCPU:    resource.MustParse("100"),
+					v1.ResourceMemory: resource.MustParse("100"),
+					v1.ResourcePods:   resource.MustParse("100"),
+				},
+			),
+			expected: Replicate(
+				[]string{"node1", "node2"},
+				api.ResourceThresholds{
+					v1.ResourceCPU:    100,
+					v1.ResourceMemory: 100,
+					v1.ResourcePods:   100,
+				},
+			),
+			normalizer: ResourceListUsageNormalizer,
+		},
+		{
+			name: "multiple normalization with over 100% usage and different totals",
+			usages: map[string]v1.ResourceList{
+				"node1": {
+					v1.ResourceCPU:    resource.MustParse("2"),
+					v1.ResourceMemory: resource.MustParse("2Gi"),
+				},
+				"node2": {
+					v1.ResourceCPU:    resource.MustParse("99"),
+					v1.ResourceMemory: resource.MustParse("99Gi"),
+				},
+				"node3": {
+					v1.ResourceCPU:    resource.MustParse("8"),
+					v1.ResourceMemory: resource.MustParse("8Gi"),
+				},
+			},
+			totals: map[string]v1.ResourceList{
+				"node1": {
+					v1.ResourceCPU:    resource.MustParse("4"),
+					v1.ResourceMemory: resource.MustParse("4Gi"),
+				},
+				"node2": {
+					v1.ResourceCPU:    resource.MustParse("100"),
+					v1.ResourceMemory: resource.MustParse("100Gi"),
+				},
+				"node3": {
+					v1.ResourceCPU:    resource.MustParse("4"),
+					v1.ResourceMemory: resource.MustParse("4Gi"),
+				},
+			},
+			expected: map[string]api.ResourceThresholds{
+				"node1": {
+					v1.ResourceCPU:    50,
+					v1.ResourceMemory: 50,
+				},
+				"node2": {
+					v1.ResourceCPU:    99,
+					v1.ResourceMemory: 99,
+				},
+				"node3": {
+					v1.ResourceCPU:    100,
+					v1.ResourceMemory: 100,
+				},
+			},
+			normalizer: ResourceListUsageNormalizer,
+		},
+	} {
+		t.Run(tt.name, func(t *testing.T) {
+			result := Normalize(tt.usages, tt.totals, tt.normalizer)
+			if !reflect.DeepEqual(result, tt.expected) {
+				t.Fatalf("unexpected result: %v", result)
+			}
+		})
+	}
+}
+
+func TestAverage(t *testing.T) {
+	for _, tt := range []struct {
+		name     string
+		usage    map[string]v1.ResourceList
+		limits   map[string]v1.ResourceList
+		expected api.ResourceThresholds
+	}{
+		{
+			name:     "empty usage",
+			usage:    map[string]v1.ResourceList{},
+			limits:   map[string]v1.ResourceList{},
+			expected: api.ResourceThresholds{},
+		},
+		{
+			name: "fifty percent usage",
+			usage: map[string]v1.ResourceList{
+				"node1": {
+					v1.ResourceCPU:    resource.MustParse("1"),
+					v1.ResourceMemory: resource.MustParse("6"),
+				},
+				"node2": {
+					v1.ResourceCPU:    resource.MustParse("2"),
+					v1.ResourceMemory: resource.MustParse("6"),
+				},
+			},
+			limits: map[string]v1.ResourceList{
+				"node1": {
+					v1.ResourceCPU:    resource.MustParse("2"),
+					v1.ResourceMemory: resource.MustParse("12"),
+				},
+				"node2": {
+					v1.ResourceCPU:    resource.MustParse("4"),
+					v1.ResourceMemory: resource.MustParse("12"),
+				},
+			},
+			expected: api.ResourceThresholds{
+				v1.ResourceCPU:    50,
+				v1.ResourceMemory: 50,
+			},
+		},
+		{
+			name: "mixed percent usage",
+			usage: map[string]v1.ResourceList{
+				"node1": {
+					v1.ResourceCPU:    resource.MustParse("10"),
+					v1.ResourceMemory: resource.MustParse("80"),
+					v1.ResourcePods:   resource.MustParse("20"),
+				},
+				"node2": {
+					v1.ResourceCPU:    resource.MustParse("20"),
+					v1.ResourceMemory: resource.MustParse("60"),
+					v1.ResourcePods:   resource.MustParse("20"),
+				},
+			},
+			limits: Replicate(
+				[]string{"node1", "node2"},
+				v1.ResourceList{
+					v1.ResourceCPU:    resource.MustParse("100"),
+					v1.ResourceMemory: resource.MustParse("100"),
+					v1.ResourcePods:   resource.MustParse("10000"),
+				},
+			),
+			expected: api.ResourceThresholds{
+				v1.ResourceCPU:    15,
+				v1.ResourceMemory: 70,
+				v1.ResourcePods:   0.2,
+			},
+		},
+		{
+			name: "mixed limits",
+			usage: map[string]v1.ResourceList{
+				"node1": {
+					v1.ResourceCPU:    resource.MustParse("10"),
+					v1.ResourceMemory: resource.MustParse("30"),
+					v1.ResourcePods:   resource.MustParse("200"),
+				},
+				"node2": {
+					v1.ResourceCPU:    resource.MustParse("10"),
+					v1.ResourceMemory: resource.MustParse("72"),
+					v1.ResourcePods:   resource.MustParse("200"),
+				},
+			},
+			limits: map[string]v1.ResourceList{
+				"node1": {
+					v1.ResourceCPU:    resource.MustParse("10"),
+					v1.ResourceMemory: resource.MustParse("100"),
+					v1.ResourcePods:   resource.MustParse("1000"),
+				},
+				"node2": {
+					v1.ResourceCPU:    resource.MustParse("1000"),
+					v1.ResourceMemory: resource.MustParse("180"),
+					v1.ResourcePods:   resource.MustParse("10"),
+				},
+			},
+			expected: api.ResourceThresholds{
+				v1.ResourceCPU:    50.5,
+				v1.ResourceMemory: 35,
+				v1.ResourcePods:   60,
+			},
+		},
+		{
+			name: "some nodes missing some resources",
+			usage: map[string]v1.ResourceList{
+				"node1": {
+					"limit-exists-in-all":  resource.MustParse("10"),
+					"limit-exists-in-two":  resource.MustParse("11"),
+					"limit-does-not-exist": resource.MustParse("12"),
+					"usage-exists-in-all":  resource.MustParse("13"),
+					"usage-exists-in-two":  resource.MustParse("20"),
+				},
+				"node2": {
+					"limit-exists-in-all":  resource.MustParse("10"),
+					"limit-exists-in-two":  resource.MustParse("11"),
+					"limit-does-not-exist": resource.MustParse("12"),
+					"usage-exists-in-all":  resource.MustParse("13"),
+					"usage-exists-in-two":  resource.MustParse("20"),
+				},
+				"node3": {
+					"limit-exists-in-all":  resource.MustParse("10"),
+					"limit-exists-in-two":  resource.MustParse("11"),
+					"limit-does-not-exist": resource.MustParse("12"),
+					"usage-exists-in-all":  resource.MustParse("13"),
+				},
+				"node4": {
+					"limit-exists-in-all":  resource.MustParse("10"),
+					"limit-exists-in-two":  resource.MustParse("11"),
+					"limit-does-not-exist": resource.MustParse("12"),
+					"usage-exists-in-all":  resource.MustParse("13"),
+				},
+				"node5": {
+					"random-usage-without-limit": resource.MustParse("10"),
+				},
+			},
+			limits: map[string]v1.ResourceList{
+				"node1": {
+					"limit-exists-in-all":  resource.MustParse("100"),
+					"limit-exists-in-two":  resource.MustParse("100"),
+					"usage-exists-in-all":  resource.MustParse("100"),
+					"usage-exists-in-two":  resource.MustParse("100"),
+					"usage-does-not-exist": resource.MustParse("100"),
+				},
+				"node2": {
+					"limit-exists-in-all":  resource.MustParse("100"),
+					"limit-exists-in-two":  resource.MustParse("100"),
+					"usage-exists-in-all":  resource.MustParse("100"),
+					"usage-exists-in-two":  resource.MustParse("100"),
+					"usage-does-not-exist": resource.MustParse("100"),
+				},
+				"node3": {
+					"limit-exists-in-all":  resource.MustParse("100"),
+					"usage-exists-in-all":  resource.MustParse("100"),
+					"usage-exists-in-two":  resource.MustParse("100"),
+					"usage-does-not-exist": resource.MustParse("100"),
+				},
+				"node4": {
+					"limit-exists-in-all":  resource.MustParse("100"),
+					"usage-exists-in-all":  resource.MustParse("100"),
+					"usage-exists-in-two":  resource.MustParse("100"),
+					"usage-does-not-exist": resource.MustParse("100"),
+				},
+				"node5": {
+					"random-limit-without-usage": resource.MustParse("100"),
+				},
+			},
+			expected: api.ResourceThresholds{
+				"limit-exists-in-all": 10,
+				"limit-exists-in-two": 11,
+				"usage-exists-in-all": 13,
+				"usage-exists-in-two": 20,
+			},
+		},
+	} {
+		t.Run(tt.name, func(t *testing.T) {
+			average := Average(
+				Normalize(
+					tt.usage, tt.limits, ResourceListUsageNormalizer,
+				),
+			)
+			if !reflect.DeepEqual(average, tt.expected) {
+				t.Fatalf("unexpected result: %v, expected: %v", average, tt.expected)
+			}
+		})
+	}
+}
+
+func TestSum(t *testing.T) {
+	for _, tt := range []struct {
+		name       string
+		data       api.ResourceThresholds
+		deviations []api.ResourceThresholds
+		expected   []api.ResourceThresholds
+	}{
+		{
+			name: "single deviation",
+			data: api.ResourceThresholds{
+				v1.ResourceCPU:    50,
+				v1.ResourceMemory: 50,
+				v1.ResourcePods:   50,
+			},
+			deviations: []api.ResourceThresholds{
+				{
+					v1.ResourceCPU:    1,
+					v1.ResourceMemory: 1,
+					v1.ResourcePods:   1,
+				},
+				{
+					v1.ResourceCPU:    2,
+					v1.ResourceMemory: 2,
+					v1.ResourcePods:   2,
+				},
+				{
+					v1.ResourceCPU:    3,
+					v1.ResourceMemory: 3,
+					v1.ResourcePods:   3,
+				},
+			},
+			expected: []api.ResourceThresholds{
+				{
+					v1.ResourceCPU:    51,
+					v1.ResourceMemory: 51,
+					v1.ResourcePods:   51,
+				},
+				{
+					v1.ResourceCPU:    52,
+					v1.ResourceMemory: 52,
+					v1.ResourcePods:   52,
+				},
+				{
+					v1.ResourceCPU:    53,
+					v1.ResourceMemory: 53,
+					v1.ResourcePods:   53,
+				},
+			},
+		},
+		{
+			name: "deviate with negative values",
+			data: api.ResourceThresholds{
+				v1.ResourceCPU:    50,
+				v1.ResourceMemory: 50,
+				v1.ResourcePods:   50,
+			},
+			deviations: []api.ResourceThresholds{
+				{
+					v1.ResourceCPU:    -2,
+					v1.ResourceMemory: -2,
+					v1.ResourcePods:   -2,
+				},
+				{
+					v1.ResourceCPU:    -1,
+					v1.ResourceMemory: -1,
+					v1.ResourcePods:   -1,
+				},
+				{
+					v1.ResourceCPU:    0,
+					v1.ResourceMemory: 0,
+					v1.ResourcePods:   0,
+				},
+				{
+					v1.ResourceCPU:    1,
+					v1.ResourceMemory: 1,
+					v1.ResourcePods:   1,
+				},
+				{
+					v1.ResourceCPU:    2,
+					v1.ResourceMemory: 2,
+					v1.ResourcePods:   2,
+				},
+			},
+			expected: []api.ResourceThresholds{
+				{
+					v1.ResourceCPU:    48,
+					v1.ResourceMemory: 48,
+					v1.ResourcePods:   48,
+				},
+				{
+					v1.ResourceCPU:    49,
+					v1.ResourceMemory: 49,
+					v1.ResourcePods:   49,
+				},
+				{
+					v1.ResourceCPU:    50,
+					v1.ResourceMemory: 50,
+					v1.ResourcePods:   50,
+				},
+				{
+					v1.ResourceCPU:    51,
+					v1.ResourceMemory: 51,
+					v1.ResourcePods:   51,
+				},
+				{
+					v1.ResourceCPU:    52,
+					v1.ResourceMemory: 52,
+					v1.ResourcePods:   52,
+				},
+			},
+		},
+	} {
+		t.Run(tt.name, func(t *testing.T) {
+			result := []api.ResourceThresholds{}
+			for _, deviation := range tt.deviations {
+				partial := Sum(tt.data, deviation)
+				result = append(result, partial)
+			}
+
+			if len(result) != len(tt.deviations) {
+				t.Fatalf("unexpected result: %v", result)
+			}
+			if !reflect.DeepEqual(result, tt.expected) {
+				fmt.Printf("%T, %T\n", result, tt.expected)
+				t.Fatalf("unexpected result: %v", result)
+			}
+		})
+	}
+}
+
+func TestClamp(t *testing.T) {
+	for _, tt := range []struct {
+		name     string
+		data     []api.ResourceThresholds
+		minimum  api.Percentage
+		maximum  api.Percentage
+		expected []api.ResourceThresholds
+	}{
+		{
+			name: "all over the limit",
+			data: []api.ResourceThresholds{
+				{
+					v1.ResourceCPU:    50,
+					v1.ResourceMemory: 50,
+					v1.ResourcePods:   50,
+				},
+			},
+			minimum: 10,
+			maximum: 20,
+			expected: []api.ResourceThresholds{
+				{
+					v1.ResourceCPU:    20,
+					v1.ResourceMemory: 20,
+					v1.ResourcePods:   20,
+				},
+			},
+		},
+		{
+			name: "some over some below the limits",
+			data: []api.ResourceThresholds{
+				{
+					v1.ResourceCPU:    7,
+					v1.ResourceMemory: 8,
+					v1.ResourcePods:   88,
+				},
+			},
+			minimum: 10,
+			maximum: 20,
+			expected: []api.ResourceThresholds{
+				{
+					v1.ResourceCPU:    10,
+					v1.ResourceMemory: 10,
+					v1.ResourcePods:   20,
+				},
+			},
+		},
+		{
+			name: "all within the limits",
+			data: []api.ResourceThresholds{
+				{
+					v1.ResourceCPU:    15,
+					v1.ResourceMemory: 15,
+					v1.ResourcePods:   15,
+				},
+			},
+			minimum: 10,
+			maximum: 20,
+			expected: []api.ResourceThresholds{
+				{
+					v1.ResourceCPU:    15,
+					v1.ResourceMemory: 15,
+					v1.ResourcePods:   15,
+				},
+			},
+		},
+	} {
+		t.Run(tt.name, func(t *testing.T) {
+			fn := func(thresholds api.ResourceThresholds) api.ResourceThresholds {
+				return Clamp(thresholds, tt.minimum, tt.maximum)
+			}
+			result := Map(tt.data, fn)
+			if !reflect.DeepEqual(result, tt.expected) {
+				t.Fatalf("unexpected result: %v", result)
+			}
+		})
+	}
+}