Refractoring lownodeutilization - extracting common functions

pkg/descheduler/descheduler.go

@@ -19,6 +19,7 @@ package descheduler
 import (
 	"context"
 	"fmt"
+	"sigs.k8s.io/descheduler/pkg/descheduler/strategies/nodeutilization"
 
 	v1 "k8s.io/api/core/v1"
 	clientset "k8s.io/client-go/kubernetes"
@@ -74,7 +75,7 @@ func RunDeschedulerStrategies(ctx context.Context, rs *options.DeschedulerServer
 
 	strategyFuncs := map[api.StrategyName]strategyFunction{
 		"RemoveDuplicates":                            strategies.RemoveDuplicatePods,
-		"LowNodeUtilization":                          strategies.LowNodeUtilization,
+		"LowNodeUtilization":                          nodeutilization.LowNodeUtilization,
 		"RemovePodsViolatingInterPodAntiAffinity":     strategies.RemovePodsViolatingInterPodAntiAffinity,
 		"RemovePodsViolatingNodeAffinity":             strategies.RemovePodsViolatingNodeAffinity,
 		"RemovePodsViolatingNodeTaints":               strategies.RemovePodsViolatingNodeTaints,

pkg/descheduler/strategies/nodeutilization/lownodeutilization.go

@@ -0,0 +1,170 @@
+/*
+Copyright 2017 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 nodeutilization
+
+import (
+	"context"
+	"fmt"
+	v1 "k8s.io/api/core/v1"
+	clientset "k8s.io/client-go/kubernetes"
+	"k8s.io/klog/v2"
+
+	"sigs.k8s.io/descheduler/pkg/api"
+	"sigs.k8s.io/descheduler/pkg/descheduler/evictions"
+	nodeutil "sigs.k8s.io/descheduler/pkg/descheduler/node"
+	"sigs.k8s.io/descheduler/pkg/utils"
+)
+
+// LowNodeUtilization evicts pods from overutilized nodes to underutilized nodes. Note that CPU/Memory requests are used
+// to calculate nodes' utilization and not the actual resource usage.
+func LowNodeUtilization(ctx context.Context, client clientset.Interface, strategy api.DeschedulerStrategy, nodes []*v1.Node, podEvictor *evictions.PodEvictor) {
+	// TODO: May be create a struct for the strategy as well, so that we don't have to pass along the all the params?
+	if err := validateLowNodeUtilizationParams(strategy.Params); err != nil {
+		klog.ErrorS(err, "Invalid LowNodeUtilization parameters")
+		return
+	}
+	thresholdPriority, err := utils.GetPriorityFromStrategyParams(ctx, client, strategy.Params)
+	if err != nil {
+		klog.ErrorS(err, "Failed to get threshold priority from strategy's params")
+		return
+	}
+
+	nodeFit := false
+	if strategy.Params != nil {
+		nodeFit = strategy.Params.NodeFit
+	}
+
+	thresholds := strategy.Params.NodeResourceUtilizationThresholds.Thresholds
+	targetThresholds := strategy.Params.NodeResourceUtilizationThresholds.TargetThresholds
+	if err := validateStrategyConfig(thresholds, targetThresholds); err != nil {
+		klog.ErrorS(err, "LowNodeUtilization config is not valid")
+		return
+	}
+	// check if Pods/CPU/Mem are set, if not, set them to 100
+	if _, ok := thresholds[v1.ResourcePods]; !ok {
+		thresholds[v1.ResourcePods] = MaxResourcePercentage
+		targetThresholds[v1.ResourcePods] = MaxResourcePercentage
+	}
+	if _, ok := thresholds[v1.ResourceCPU]; !ok {
+		thresholds[v1.ResourceCPU] = MaxResourcePercentage
+		targetThresholds[v1.ResourceCPU] = MaxResourcePercentage
+	}
+	if _, ok := thresholds[v1.ResourceMemory]; !ok {
+		thresholds[v1.ResourceMemory] = MaxResourcePercentage
+		targetThresholds[v1.ResourceMemory] = MaxResourcePercentage
+	}
+	resourceNames := getResourceNames(thresholds)
+
+	lowNodes, targetNodes := classifyNodes(
+		getNodeUsage(ctx, client, nodes, thresholds, targetThresholds, resourceNames),
+		// The node has to be schedulable (to be able to move workload there)
+		func(node *v1.Node, usage NodeUsage) bool {
+			if nodeutil.IsNodeUnschedulable(node) {
+				klog.V(2).InfoS("Node is unschedulable, thus not considered as underutilized", "node", klog.KObj(node))
+				return false
+			}
+			return isNodeWithLowUtilization(usage)
+		},
+		func(node *v1.Node, usage NodeUsage) bool {
+			return isNodeAboveTargetUtilization(usage)
+		},
+	)
+
+	// log message in one line
+	keysAndValues := []interface{}{
+		"CPU", thresholds[v1.ResourceCPU],
+		"Mem", thresholds[v1.ResourceMemory],
+		"Pods", thresholds[v1.ResourcePods],
+	}
+	for name := range thresholds {
+		if !isBasicResource(name) {
+			keysAndValues = append(keysAndValues, string(name), int64(thresholds[name]))
+		}
+	}
+	klog.V(1).InfoS("Criteria for a node under utilization", keysAndValues...)
+	klog.V(1).InfoS("Number of underutilized nodes", "totalNumber", len(lowNodes))
+
+	// log message in one line
+	keysAndValues = []interface{}{
+		"CPU", targetThresholds[v1.ResourceCPU],
+		"Mem", targetThresholds[v1.ResourceMemory],
+		"Pods", targetThresholds[v1.ResourcePods],
+	}
+	for name := range targetThresholds {
+		if !isBasicResource(name) {
+			keysAndValues = append(keysAndValues, string(name), int64(targetThresholds[name]))
+		}
+	}
+	klog.V(1).InfoS("Criteria for a node above target utilization", keysAndValues...)
+	klog.V(1).InfoS("Number of overutilized nodes", "totalNumber", len(targetNodes))
+
+	if len(lowNodes) == 0 {
+		klog.V(1).InfoS("No node is underutilized, nothing to do here, you might tune your thresholds further")
+		return
+	}
+
+	if len(lowNodes) < strategy.Params.NodeResourceUtilizationThresholds.NumberOfNodes {
+		klog.V(1).InfoS("Number of nodes underutilized is less than NumberOfNodes, nothing to do here", "underutilizedNodes", len(lowNodes), "numberOfNodes", strategy.Params.NodeResourceUtilizationThresholds.NumberOfNodes)
+		return
+	}
+
+	if len(lowNodes) == len(nodes) {
+		klog.V(1).InfoS("All nodes are underutilized, nothing to do here")
+		return
+	}
+
+	if len(targetNodes) == 0 {
+		klog.V(1).InfoS("All nodes are under target utilization, nothing to do here")
+		return
+	}
+
+	evictable := podEvictor.Evictable(evictions.WithPriorityThreshold(thresholdPriority), evictions.WithNodeFit(nodeFit))
+
+	evictPodsFromTargetNodes(
+		ctx,
+		targetNodes,
+		lowNodes,
+		podEvictor,
+		evictable.IsEvictable,
+		resourceNames)
+
+	klog.V(1).InfoS("Total number of pods evicted", "evictedPods", podEvictor.TotalEvicted())
+}
+
+// validateStrategyConfig checks if the strategy's config is valid
+func validateStrategyConfig(thresholds, targetThresholds api.ResourceThresholds) error {
+	// validate thresholds and targetThresholds config
+	if err := validateThresholds(thresholds); err != nil {
+		return fmt.Errorf("thresholds config is not valid: %v", err)
+	}
+	if err := validateThresholds(targetThresholds); err != nil {
+		return fmt.Errorf("targetThresholds config is not valid: %v", err)
+	}
+
+	// validate if thresholds and targetThresholds have same resources configured
+	if len(thresholds) != len(targetThresholds) {
+		return fmt.Errorf("thresholds and targetThresholds configured different resources")
+	}
+	for resourceName, value := range thresholds {
+		if targetValue, ok := targetThresholds[resourceName]; !ok {
+			return fmt.Errorf("thresholds and targetThresholds configured different resources")
+		} else if value > targetValue {
+			return fmt.Errorf("thresholds' %v percentage is greater than targetThresholds'", resourceName)
+		}
+	}
+	return nil
+}

pkg/descheduler/strategies/nodeutilization/lownodeutilization_test.go

@@ -14,12 +14,11 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-package strategies
+package nodeutilization
 
 import (
 	"context"
 	"fmt"
-	"math"
 	"strings"
 	"testing"
 
@@ -36,12 +35,6 @@ import (
 	"sigs.k8s.io/descheduler/test"
 )
 
-var (
-	lowPriority      = int32(0)
-	highPriority     = int32(10000)
-	extendedResource = v1.ResourceName("example.com/foo")
-)
-
 func TestLowNodeUtilization(t *testing.T) {
 	ctx := context.Background()
 	n1NodeName := "n1"
@@ -979,93 +972,7 @@ func TestValidateStrategyConfig(t *testing.T) {
 	}
 }
 
-func TestValidateThresholds(t *testing.T) {
-	tests := []struct {
-		name    string
-		input   api.ResourceThresholds
-		errInfo error
-	}{
-		{
-			name:    "passing nil map for threshold",
-			input:   nil,
-			errInfo: fmt.Errorf("no resource threshold is configured"),
-		},
-		{
-			name:    "passing no threshold",
-			input:   api.ResourceThresholds{},
-			errInfo: fmt.Errorf("no resource threshold is configured"),
-		},
-		{
-			name: "passing extended resource name other than cpu/memory/pods",
-			input: api.ResourceThresholds{
-				v1.ResourceCPU:   40,
-				extendedResource: 50,
-			},
-			errInfo: nil,
-		},
-		{
-			name: "passing invalid resource value",
-			input: api.ResourceThresholds{
-				v1.ResourceCPU:    110,
-				v1.ResourceMemory: 80,
-			},
-			errInfo: fmt.Errorf("%v threshold not in [%v, %v] range", v1.ResourceCPU, MinResourcePercentage, MaxResourcePercentage),
-		},
-		{
-			name: "passing a valid threshold with max and min resource value",
-			input: api.ResourceThresholds{
-				v1.ResourceCPU:    100,
-				v1.ResourceMemory: 0,
-			},
-			errInfo: nil,
-		},
-		{
-			name: "passing a valid threshold with only cpu",
-			input: api.ResourceThresholds{
-				v1.ResourceCPU: 80,
-			},
-			errInfo: nil,
-		},
-		{
-			name: "passing a valid threshold with cpu, memory and pods",
-			input: api.ResourceThresholds{
-				v1.ResourceCPU:    20,
-				v1.ResourceMemory: 30,
-				v1.ResourcePods:   40,
-			},
-			errInfo: nil,
-		},
-		{
-			name: "passing a valid threshold with only extended resource",
-			input: api.ResourceThresholds{
-				extendedResource: 80,
-			},
-			errInfo: nil,
-		},
-		{
-			name: "passing a valid threshold with cpu, memory, pods and extended resource",
-			input: api.ResourceThresholds{
-				v1.ResourceCPU:    20,
-				v1.ResourceMemory: 30,
-				v1.ResourcePods:   40,
-				extendedResource:  50,
-			},
-			errInfo: nil,
-		},
-	}
 
-	for _, test := range tests {
-		validateErr := validateThresholds(test.input)
-
-		if validateErr == nil || test.errInfo == nil {
-			if validateErr != test.errInfo {
-				t.Errorf("expected validity of threshold: %#v to be %v but got %v instead", test.input, test.errInfo, validateErr)
-			}
-		} else if validateErr.Error() != test.errInfo.Error() {
-			t.Errorf("expected validity of threshold: %#v to be %v but got %v instead", test.input, test.errInfo, validateErr)
-		}
-	}
-}
 
 func TestWithTaints(t *testing.T) {
 	ctx := context.Background()
@@ -1198,41 +1105,3 @@ func TestWithTaints(t *testing.T) {
 		})
 	}
 }
-
-func TestResourceUsagePercentages(t *testing.T) {
-	resourceUsagePercentage := resourceUsagePercentages(NodeUsage{
-		node: &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),
-				},
-			},
-		},
-		usage: map[v1.ResourceName]*resource.Quantity{
-			v1.ResourceCPU:    resource.NewMilliQuantity(1220, resource.DecimalSI),
-			v1.ResourceMemory: resource.NewQuantity(3038982964, resource.BinarySI),
-			v1.ResourcePods:   resource.NewQuantity(11, resource.BinarySI),
-		},
-	})
-
-	expectedUsageInIntPercentage := map[v1.ResourceName]float64{
-		v1.ResourceCPU:    63,
-		v1.ResourceMemory: 90,
-		v1.ResourcePods:   37,
-	}
-
-	for resourceName, percentage := range expectedUsageInIntPercentage {
-		if math.Floor(resourceUsagePercentage[resourceName]) != percentage {
-			t.Errorf("Incorrect percentange computation, expected %v, got math.Floor(%v) instead", percentage, resourceUsagePercentage[resourceName])
-		}
-	}
-
-	t.Logf("resourceUsagePercentage: %#v\n", resourceUsagePercentage)
-}

pkg/descheduler/strategies/nodeutilization/nodeutilization.go

@@ -1,5 +1,5 @@
 /*
-Copyright 2017 The Kubernetes Authors.
+Copyright 2021 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.
@@ -14,23 +14,20 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-package strategies
+package nodeutilization
 
 import (
 	"context"
 	"fmt"
-	"sort"
-
 	v1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/api/resource"
 	clientset "k8s.io/client-go/kubernetes"
 	"k8s.io/klog/v2"
-
 	"sigs.k8s.io/descheduler/pkg/api"
 	"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/utils"
+	"sort"
 )
 
 // NodeUsage stores a node's info, pods on it, thresholds and its resource usage
@@ -64,146 +61,6 @@ func validateLowNodeUtilizationParams(params *api.StrategyParameters) error {
 	return nil
 }
 
-// LowNodeUtilization evicts pods from overutilized nodes to underutilized nodes. Note that CPU/Memory requests are used
-// to calculate nodes' utilization and not the actual resource usage.
-func LowNodeUtilization(ctx context.Context, client clientset.Interface, strategy api.DeschedulerStrategy, nodes []*v1.Node, podEvictor *evictions.PodEvictor) {
-	// TODO: May be create a struct for the strategy as well, so that we don't have to pass along the all the params?
-	if err := validateLowNodeUtilizationParams(strategy.Params); err != nil {
-		klog.ErrorS(err, "Invalid LowNodeUtilization parameters")
-		return
-	}
-	thresholdPriority, err := utils.GetPriorityFromStrategyParams(ctx, client, strategy.Params)
-	if err != nil {
-		klog.ErrorS(err, "Failed to get threshold priority from strategy's params")
-		return
-	}
-
-	nodeFit := false
-	if strategy.Params != nil {
-		nodeFit = strategy.Params.NodeFit
-	}
-
-	thresholds := strategy.Params.NodeResourceUtilizationThresholds.Thresholds
-	targetThresholds := strategy.Params.NodeResourceUtilizationThresholds.TargetThresholds
-	if err := validateStrategyConfig(thresholds, targetThresholds); err != nil {
-		klog.ErrorS(err, "LowNodeUtilization config is not valid")
-		return
-	}
-	// check if Pods/CPU/Mem are set, if not, set them to 100
-	if _, ok := thresholds[v1.ResourcePods]; !ok {
-		thresholds[v1.ResourcePods] = MaxResourcePercentage
-		targetThresholds[v1.ResourcePods] = MaxResourcePercentage
-	}
-	if _, ok := thresholds[v1.ResourceCPU]; !ok {
-		thresholds[v1.ResourceCPU] = MaxResourcePercentage
-		targetThresholds[v1.ResourceCPU] = MaxResourcePercentage
-	}
-	if _, ok := thresholds[v1.ResourceMemory]; !ok {
-		thresholds[v1.ResourceMemory] = MaxResourcePercentage
-		targetThresholds[v1.ResourceMemory] = MaxResourcePercentage
-	}
-	resourceNames := getResourceNames(thresholds)
-
-	lowNodes, targetNodes := classifyNodes(
-		getNodeUsage(ctx, client, nodes, thresholds, targetThresholds, resourceNames),
-		// The node has to be schedulable (to be able to move workload there)
-		func(node *v1.Node, usage NodeUsage) bool {
-			if nodeutil.IsNodeUnschedulable(node) {
-				klog.V(2).InfoS("Node is unschedulable, thus not considered as underutilized", "node", klog.KObj(node))
-				return false
-			}
-			return isNodeWithLowUtilization(usage)
-		},
-		func(node *v1.Node, usage NodeUsage) bool {
-			return isNodeAboveTargetUtilization(usage)
-		},
-	)
-
-	// log message in one line
-	keysAndValues := []interface{}{
-		"CPU", thresholds[v1.ResourceCPU],
-		"Mem", thresholds[v1.ResourceMemory],
-		"Pods", thresholds[v1.ResourcePods],
-	}
-	for name := range thresholds {
-		if !isBasicResource(name) {
-			keysAndValues = append(keysAndValues, string(name), int64(float64(thresholds[name])))
-		}
-	}
-	klog.V(1).InfoS("Criteria for a node under utilization", keysAndValues...)
-	klog.V(1).InfoS("Number of underutilized nodes", "totalNumber", len(lowNodes))
-
-	// log message in one line
-	keysAndValues = []interface{}{
-		"CPU", targetThresholds[v1.ResourceCPU],
-		"Mem", targetThresholds[v1.ResourceMemory],
-		"Pods", targetThresholds[v1.ResourcePods],
-	}
-	for name := range targetThresholds {
-		if !isBasicResource(name) {
-			keysAndValues = append(keysAndValues, string(name), int64(float64(targetThresholds[name])))
-		}
-	}
-	klog.V(1).InfoS("Criteria for a node above target utilization", keysAndValues...)
-	klog.V(1).InfoS("Number of overutilized nodes", "totalNumber", len(targetNodes))
-
-	if len(lowNodes) == 0 {
-		klog.V(1).InfoS("No node is underutilized, nothing to do here, you might tune your thresholds further")
-		return
-	}
-
-	if len(lowNodes) < strategy.Params.NodeResourceUtilizationThresholds.NumberOfNodes {
-		klog.V(1).InfoS("Number of nodes underutilized is less than NumberOfNodes, nothing to do here", "underutilizedNodes", len(lowNodes), "numberOfNodes", strategy.Params.NodeResourceUtilizationThresholds.NumberOfNodes)
-		return
-	}
-
-	if len(lowNodes) == len(nodes) {
-		klog.V(1).InfoS("All nodes are underutilized, nothing to do here")
-		return
-	}
-
-	if len(targetNodes) == 0 {
-		klog.V(1).InfoS("All nodes are under target utilization, nothing to do here")
-		return
-	}
-
-	evictable := podEvictor.Evictable(evictions.WithPriorityThreshold(thresholdPriority), evictions.WithNodeFit(nodeFit))
-
-	evictPodsFromTargetNodes(
-		ctx,
-		targetNodes,
-		lowNodes,
-		podEvictor,
-		evictable.IsEvictable,
-		resourceNames)
-
-	klog.V(1).InfoS("Total number of pods evicted", "evictedPods", podEvictor.TotalEvicted())
-}
-
-// validateStrategyConfig checks if the strategy's config is valid
-func validateStrategyConfig(thresholds, targetThresholds api.ResourceThresholds) error {
-	// validate thresholds and targetThresholds config
-	if err := validateThresholds(thresholds); err != nil {
-		return fmt.Errorf("thresholds config is not valid: %v", err)
-	}
-	if err := validateThresholds(targetThresholds); err != nil {
-		return fmt.Errorf("targetThresholds config is not valid: %v", err)
-	}
-
-	// validate if thresholds and targetThresholds have same resources configured
-	if len(thresholds) != len(targetThresholds) {
-		return fmt.Errorf("thresholds and targetThresholds configured different resources")
-	}
-	for resourceName, value := range thresholds {
-		if targetValue, ok := targetThresholds[resourceName]; !ok {
-			return fmt.Errorf("thresholds and targetThresholds configured different resources")
-		} else if value > targetValue {
-			return fmt.Errorf("thresholds' %v percentage is greater than targetThresholds'", resourceName)
-		}
-	}
-	return nil
-}
-
 // validateThresholds checks if thresholds have valid resource name and resource percentage configured
 func validateThresholds(thresholds api.ResourceThresholds) error {
 	if thresholds == nil || len(thresholds) == 0 {
@@ -224,7 +81,7 @@ func getNodeUsage(
 	lowThreshold, highThreshold api.ResourceThresholds,
 	resourceNames []v1.ResourceName,
 ) []NodeUsage {
-	nodeUsageList := []NodeUsage{}
+	var nodeUsageList []NodeUsage
 
 	for _, node := range nodes {
 		pods, err := podutil.ListPodsOnANode(ctx, client, node)
@@ -388,8 +245,9 @@ func evictPods(
 	taintsOfLowNodes map[string][]v1.Taint,
 	podEvictor *evictions.PodEvictor,
 ) {
+
 	// stop if node utilization drops below target threshold or any of required capacity (cpu, memory, pods) is moved
-	continueCond := func() bool {
+	continueCond := func(nodeUsage NodeUsage, totalAvailableUsage map[v1.ResourceName]*resource.Quantity) bool {
 		if !isNodeAboveTargetUtilization(nodeUsage) {
 			return false
 		}
@@ -401,8 +259,7 @@ func evictPods(
 
 		return true
 	}
-
-	if continueCond() {
+	if continueCond(nodeUsage, totalAvailableUsage) {
 		for _, pod := range inputPods {
 			if !utils.PodToleratesTaints(pod, taintsOfLowNodes) {
 				klog.V(3).InfoS("Skipping eviction for pod, doesn't tolerate node taint", "pod", klog.KObj(pod))
@@ -443,7 +300,7 @@ func evictPods(
 
 				klog.V(3).InfoS("Updated node usage", keysAndValues...)
 				// check if node utilization drops below target threshold or any required capacity (cpu, memory, pods) is moved
-				if !continueCond() {
+				if !continueCond(nodeUsage, totalAvailableUsage) {
 					break
 				}
 			}

pkg/descheduler/strategies/nodeutilization/nodeutilization_test.go

@@ -0,0 +1,158 @@
+/*
+Copyright 2021 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 nodeutilization
+
+import (
+	"fmt"
+	v1 "k8s.io/api/core/v1"
+	"k8s.io/apimachinery/pkg/api/resource"
+	"math"
+	"sigs.k8s.io/descheduler/pkg/api"
+	"testing"
+)
+
+var (
+	lowPriority      = int32(0)
+	highPriority     = int32(10000)
+	extendedResource = v1.ResourceName("example.com/foo")
+)
+
+func TestValidateThresholds(t *testing.T) {
+	tests := []struct {
+		name    string
+		input   api.ResourceThresholds
+		errInfo error
+	}{
+		{
+			name:    "passing nil map for threshold",
+			input:   nil,
+			errInfo: fmt.Errorf("no resource threshold is configured"),
+		},
+		{
+			name:    "passing no threshold",
+			input:   api.ResourceThresholds{},
+			errInfo: fmt.Errorf("no resource threshold is configured"),
+		},
+		{
+			name: "passing extended resource name other than cpu/memory/pods",
+			input: api.ResourceThresholds{
+				v1.ResourceCPU:   40,
+				extendedResource: 50,
+			},
+			errInfo: nil,
+		},
+		{
+			name: "passing invalid resource value",
+			input: api.ResourceThresholds{
+				v1.ResourceCPU:    110,
+				v1.ResourceMemory: 80,
+			},
+			errInfo: fmt.Errorf("%v threshold not in [%v, %v] range", v1.ResourceCPU, MinResourcePercentage, MaxResourcePercentage),
+		},
+		{
+			name: "passing a valid threshold with max and min resource value",
+			input: api.ResourceThresholds{
+				v1.ResourceCPU:    100,
+				v1.ResourceMemory: 0,
+			},
+			errInfo: nil,
+		},
+		{
+			name: "passing a valid threshold with only cpu",
+			input: api.ResourceThresholds{
+				v1.ResourceCPU: 80,
+			},
+			errInfo: nil,
+		},
+		{
+			name: "passing a valid threshold with cpu, memory and pods",
+			input: api.ResourceThresholds{
+				v1.ResourceCPU:    20,
+				v1.ResourceMemory: 30,
+				v1.ResourcePods:   40,
+			},
+			errInfo: nil,
+		},
+		{
+			name: "passing a valid threshold with only extended resource",
+			input: api.ResourceThresholds{
+				extendedResource: 80,
+			},
+			errInfo: nil,
+		},
+		{
+			name: "passing a valid threshold with cpu, memory, pods and extended resource",
+			input: api.ResourceThresholds{
+				v1.ResourceCPU:    20,
+				v1.ResourceMemory: 30,
+				v1.ResourcePods:   40,
+				extendedResource:  50,
+			},
+			errInfo: nil,
+		},
+	}
+
+	for _, test := range tests {
+		validateErr := validateThresholds(test.input)
+
+		if validateErr == nil || test.errInfo == nil {
+			if validateErr != test.errInfo {
+				t.Errorf("expected validity of threshold: %#v to be %v but got %v instead", test.input, test.errInfo, validateErr)
+			}
+		} else if validateErr.Error() != test.errInfo.Error() {
+			t.Errorf("expected validity of threshold: %#v to be %v but got %v instead", test.input, test.errInfo, validateErr)
+		}
+	}
+}
+
+func TestResourceUsagePercentages(t *testing.T) {
+	resourceUsagePercentage := resourceUsagePercentages(NodeUsage{
+		node: &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),
+				},
+			},
+		},
+		usage: map[v1.ResourceName]*resource.Quantity{
+			v1.ResourceCPU:    resource.NewMilliQuantity(1220, resource.DecimalSI),
+			v1.ResourceMemory: resource.NewQuantity(3038982964, resource.BinarySI),
+			v1.ResourcePods:   resource.NewQuantity(11, resource.BinarySI),
+		},
+	})
+
+	expectedUsageInIntPercentage := map[v1.ResourceName]float64{
+		v1.ResourceCPU:    63,
+		v1.ResourceMemory: 90,
+		v1.ResourcePods:   37,
+	}
+
+	for resourceName, percentage := range expectedUsageInIntPercentage {
+		if math.Floor(resourceUsagePercentage[resourceName]) != percentage {
+			t.Errorf("Incorrect percentange computation, expected %v, got math.Floor(%v) instead", percentage, resourceUsagePercentage[resourceName])
+		}
+	}
+
+	t.Logf("resourceUsagePercentage: %#v\n", resourceUsagePercentage)
+}