Migrate EvenPodsSpread Priority as Score plugin in map/reduce style

pkg/scheduler/algorithm/priorities/even_pods_spread.go

@@ -18,6 +18,7 @@ package priorities
 
 import (
 	"context"
+	"fmt"
 	"math"
 	"sync/atomic"
 
@@ -26,6 +27,7 @@ import (
 	"k8s.io/kubernetes/pkg/scheduler/algorithm/predicates"
 	framework "k8s.io/kubernetes/pkg/scheduler/framework/v1alpha1"
 	schedulerlisters "k8s.io/kubernetes/pkg/scheduler/listers"
+	schedulernodeinfo "k8s.io/kubernetes/pkg/scheduler/nodeinfo"
 	schedutil "k8s.io/kubernetes/pkg/scheduler/util"
 
 	"k8s.io/klog"
@@ -36,67 +38,32 @@ type topologyPair struct {
 	value string
 }
 
-type topologySpreadConstraintsMap struct {
+type podTopologySpreadMap struct {
-	// nodeNameToPodCounts is keyed with node name, and valued with the number of matching pods.
+	// nodeNameSet is a string set holding all node names which have all constraints[*].topologyKey present.
-	nodeNameToPodCounts map[string]int32
+	nodeNameSet map[string]struct{}
 	// topologyPairToPodCounts is keyed with topologyPair, and valued with the number of matching pods.
-	topologyPairToPodCounts map[topologyPair]*int32
+	topologyPairToPodCounts map[topologyPair]*int64
 }
 
-func newTopologySpreadConstraintsMap() *topologySpreadConstraintsMap {
+func newTopologySpreadConstraintsMap() *podTopologySpreadMap {
-	return &topologySpreadConstraintsMap{
+	return &podTopologySpreadMap{
-		nodeNameToPodCounts:     make(map[string]int32),
+		nodeNameSet:             make(map[string]struct{}),
-		topologyPairToPodCounts: make(map[topologyPair]*int32),
+		topologyPairToPodCounts: make(map[topologyPair]*int64),
 	}
 }
 
-// Note: the <nodes> passed in are the "filtered" nodes which have passed Predicates.
+// buildPodTopologySpreadMap prepares necessary data (podTopologySpreadMap) for incoming pod on the filteredNodes.
-// This function iterates <nodes> to filter out the nodes which don't have required topologyKey(s),
+// Later Priority function will use 'podTopologySpreadMap' to perform the Scoring calculations.
-// and initialize two maps:
+func buildPodTopologySpreadMap(pod *v1.Pod, filteredNodes []*v1.Node, allNodes []*schedulernodeinfo.NodeInfo) *podTopologySpreadMap {
-// 1) t.topologyPairToPodCounts: keyed with both eligible topology pair and node names.
-// 2) t.nodeNameToPodCounts: keyed with node name, and valued with a *int32 pointer for eligible node only.
-func (t *topologySpreadConstraintsMap) initialize(pod *v1.Pod, nodes []*v1.Node) {
-	constraints := getSoftTopologySpreadConstraints(pod)
-	for _, node := range nodes {
-		if !predicates.NodeLabelsMatchSpreadConstraints(node.Labels, constraints) {
-			continue
-		}
-		for _, constraint := range constraints {
-			pair := topologyPair{key: constraint.TopologyKey, value: node.Labels[constraint.TopologyKey]}
-			if t.topologyPairToPodCounts[pair] == nil {
-				t.topologyPairToPodCounts[pair] = new(int32)
-			}
-		}
-		t.nodeNameToPodCounts[node.Name] = 0
-		// For those nodes which don't have all required topologyKeys present, it's intentional to keep
-		// those entries absent in nodeNameToPodCounts, so that we're able to score them to 0 afterwards.
-	}
-}
-
-// CalculateEvenPodsSpreadPriority computes a score by checking through the topologySpreadConstraints
-// that are with WhenUnsatisfiable=ScheduleAnyway (a.k.a soft constraint).
-// The function works as below:
-// 1) In all nodes, calculate the number of pods which match <pod>'s soft topology spread constraints.
-// 2) Group the number calculated in 1) by topologyPair, and sum up to corresponding candidate nodes.
-// 3) Finally normalize the number to 0~10. The node with the highest score is the most preferred.
-// Note: Symmetry is not applicable. We only weigh how incomingPod matches existingPod.
-// Whether existingPod matches incomingPod doesn't contribute to the final score.
-// This is different from the Affinity API.
-func CalculateEvenPodsSpreadPriority(pod *v1.Pod, sharedLister schedulerlisters.SharedLister, nodes []*v1.Node) (framework.NodeScoreList, error) {
-	result := make(framework.NodeScoreList, len(nodes))
 	// return if incoming pod doesn't have soft topology spread constraints.
 	constraints := getSoftTopologySpreadConstraints(pod)
-	if len(constraints) == 0 {
+	if len(constraints) == 0 || len(filteredNodes) == 0 || len(allNodes) == 0 {
-		return result, nil
+		return nil
 	}
 
-	allNodes, err := sharedLister.NodeInfos().List()
+	// initialize podTopologySpreadMap which will be used in Score plugin.
-	if err != nil {
+	m := newTopologySpreadConstraintsMap()
-		return nil, err
+	m.initialize(pod, filteredNodes)
-	}
-
-	t := newTopologySpreadConstraintsMap()
-	t.initialize(pod, nodes)
 
 	errCh := schedutil.NewErrorChannel()
 	ctx, cancel := context.WithCancel(context.Background())
@@ -117,12 +84,12 @@ func CalculateEvenPodsSpreadPriority(pod *v1.Pod, sharedLister schedulerlisters.
 			pair := topologyPair{key: constraint.TopologyKey, value: node.Labels[constraint.TopologyKey]}
 			// If current topology pair is not associated with any candidate node,
 			// continue to avoid unnecessary calculation.
-			if t.topologyPairToPodCounts[pair] == nil {
+			if m.topologyPairToPodCounts[pair] == nil {
 				continue
 			}
 
 			// <matchSum> indicates how many pods (on current node) match the <constraint>.
-			matchSum := int32(0)
+			matchSum := int64(0)
 			for _, existingPod := range nodeInfo.Pods() {
 				match, err := predicates.PodMatchesSpreadConstraint(existingPod.Labels, constraint)
 				if err != nil {
@@ -133,67 +100,132 @@ func CalculateEvenPodsSpreadPriority(pod *v1.Pod, sharedLister schedulerlisters.
 					matchSum++
 				}
 			}
-			atomic.AddInt32(t.topologyPairToPodCounts[pair], matchSum)
+			atomic.AddInt64(m.topologyPairToPodCounts[pair], matchSum)
 		}
 	}
 	workqueue.ParallelizeUntil(ctx, 16, len(allNodes), processAllNode)
 	if err := errCh.ReceiveError(); err != nil {
-		return nil, err
+		klog.Error(err)
+		return nil
 	}
 
-	var minCount int32 = math.MaxInt32
+	return m
-	// <total> sums up the number of matching pods on each qualified topology pair
+}
-	var total int32
+
-	for _, node := range nodes {
+// initialize iterates "filteredNodes" to filter out the nodes which don't have required topologyKey(s),
-		if _, ok := t.nodeNameToPodCounts[node.Name]; !ok {
+// and initialize two maps:
+// 1) m.topologyPairToPodCounts: keyed with both eligible topology pair and node names.
+// 2) m.nodeNameSet: keyed with node name, and valued with a *int64 pointer for eligible node only.
+func (m *podTopologySpreadMap) initialize(pod *v1.Pod, filteredNodes []*v1.Node) {
+	constraints := getSoftTopologySpreadConstraints(pod)
+	for _, node := range filteredNodes {
+		if !predicates.NodeLabelsMatchSpreadConstraints(node.Labels, constraints) {
 			continue
 		}
-
-		// For each present <pair>, current node gets a credit of <matchSum>.
-		// And we add <matchSum> to <t.total> to reverse the final score later.
 		for _, constraint := range constraints {
-			if tpVal, ok := node.Labels[constraint.TopologyKey]; ok {
+			pair := topologyPair{key: constraint.TopologyKey, value: node.Labels[constraint.TopologyKey]}
-				pair := topologyPair{key: constraint.TopologyKey, value: tpVal}
+			if m.topologyPairToPodCounts[pair] == nil {
-				matchSum := *t.topologyPairToPodCounts[pair]
+				m.topologyPairToPodCounts[pair] = new(int64)
-				t.nodeNameToPodCounts[node.Name] += matchSum
-				total += matchSum
 			}
 		}
-		if t.nodeNameToPodCounts[node.Name] < minCount {
+		m.nodeNameSet[node.Name] = struct{}{}
-			minCount = t.nodeNameToPodCounts[node.Name]
+		// For those nodes which don't have all required topologyKeys present, it's intentional to leave
+		// their entries absent in nodeNameSet, so that we're able to score them to 0 afterwards.
+	}
+}
+
+// CalculateEvenPodsSpreadPriorityMap calculate the number of matching pods on the passed-in "node",
+// and return the number as Score.
+func CalculateEvenPodsSpreadPriorityMap(pod *v1.Pod, meta interface{}, nodeInfo *schedulernodeinfo.NodeInfo) (framework.NodeScore, error) {
+	node := nodeInfo.Node()
+	if node == nil {
+		return framework.NodeScore{}, fmt.Errorf("node not found")
+	}
+
+	var m *podTopologySpreadMap
+	if priorityMeta, ok := meta.(*priorityMetadata); ok {
+		m = priorityMeta.podTopologySpreadMap
+	}
+	if m == nil {
+		return framework.NodeScore{}, nil
+	}
+
+	// no need to continue if the node is not qualified.
+	if _, ok := m.nodeNameSet[node.Name]; !ok {
+		return framework.NodeScore{Name: node.Name, Score: 0}, nil
+	}
+
+	constraints := getSoftTopologySpreadConstraints(pod)
+	// For each present <pair>, current node gets a credit of <matchSum>.
+	// And we sum up <matchSum> and return it as this node's score.
+	var score int64
+	for _, constraint := range constraints {
+		if tpVal, ok := node.Labels[constraint.TopologyKey]; ok {
+			pair := topologyPair{key: constraint.TopologyKey, value: tpVal}
+			matchSum := *m.topologyPairToPodCounts[pair]
+			score += matchSum
+		}
+	}
+	return framework.NodeScore{Name: node.Name, Score: score}, nil
+}
+
+// CalculateEvenPodsSpreadPriorityReduce normalizes the score for each filteredNode,
+// The basic rule is: the bigger the score(matching number of pods) is, the smaller the
+// final normalized score will be.
+func CalculateEvenPodsSpreadPriorityReduce(pod *v1.Pod, meta interface{}, sharedLister schedulerlisters.SharedLister,
+	result framework.NodeScoreList) error {
+	var m *podTopologySpreadMap
+	if priorityMeta, ok := meta.(*priorityMetadata); ok {
+		m = priorityMeta.podTopologySpreadMap
+	}
+	if m == nil {
+		return nil
+	}
+
+	// Calculate the summed <total> score and <minScore>.
+	var minScore int64 = math.MaxInt64
+	var total int64
+	for _, score := range result {
+		// it's mandatory to check if <score.Name> is present in m.nodeNameSet
+		if _, ok := m.nodeNameSet[score.Name]; !ok {
+			continue
+		}
+		total += score.Score
+		if score.Score < minScore {
+			minScore = score.Score
 		}
 	}
 
-	// calculate final priority score for each node
+	maxMinDiff := total - minScore
-	// TODO(Huang-Wei): in alpha version, we keep the formula as simple as possible.
+	for i := range result {
-	// current version ranks the nodes properly, but it doesn't take MaxSkew into
+		nodeInfo, err := sharedLister.NodeInfos().Get(result[i].Name)
-	// consideration, we may come up with a better formula in the future.
+		if err != nil {
-	maxMinDiff := total - minCount
+			return err
-	for i := range nodes {
+		}
-		node := nodes[i]
+		node := nodeInfo.Node()
-		result[i].Name = node.Name
+		// Debugging purpose: print the score for each node.
-
+		// Score must be a pointer here, otherwise it's always 0.
-		// debugging purpose: print the value for each node
-		// score must be pointer here, otherwise it's always 0
 		if klog.V(10) {
 			defer func(score *int64, nodeName string) {
-				klog.Infof("%v -> %v: EvenPodsSpreadPriority, Score: (%d)", pod.Name, nodeName, *score)
+				klog.Infof("%v -> %v: PodTopologySpread NormalizeScore, Score: (%d)", pod.Name, nodeName, *score)
 			}(&result[i].Score, node.Name)
 		}
 
-		if _, ok := t.nodeNameToPodCounts[node.Name]; !ok {
-			result[i].Score = 0
-			continue
-		}
 		if maxMinDiff == 0 {
 			result[i].Score = framework.MaxNodeScore
 			continue
 		}
-		fScore := float64(framework.MaxNodeScore) * (float64(total-t.nodeNameToPodCounts[node.Name]) / float64(maxMinDiff))
+
+		if _, ok := m.nodeNameSet[node.Name]; !ok {
+			result[i].Score = 0
+			continue
+		}
+
+		flippedScore := total - result[i].Score
+		fScore := float64(framework.MaxNodeScore) * (float64(flippedScore) / float64(maxMinDiff))
 		result[i].Score = int64(fScore)
 	}
-
+	return nil
-	return result, nil
 }
 
 // TODO(Huang-Wei): combine this with getHardTopologySpreadConstraints() in predicates package

pkg/scheduler/algorithm/priorities/even_pods_spread_test.go

@@ -26,13 +26,13 @@ import (
 	st "k8s.io/kubernetes/pkg/scheduler/testing"
 )
 
-func Test_topologySpreadConstraintsMap_initialize(t *testing.T) {
+func Test_podTopologySpreadMap_initialize(t *testing.T) {
 	tests := []struct {
 		name                string
 		pod                 *v1.Pod
 		nodes               []*v1.Node
-		wantNodeNameMap     map[string]int32
+		wantNodeNameSet     map[string]struct{}
-		wantTopologyPairMap map[topologyPair]*int32
+		wantTopologyPairMap map[topologyPair]*int64
 	}{
 		{
 			name: "normal case",
@@ -45,17 +45,17 @@ func Test_topologySpreadConstraintsMap_initialize(t *testing.T) {
 				st.MakeNode().Name("node-b").Label("zone", "zone1").Label("node", "node-b").Obj(),
 				st.MakeNode().Name("node-x").Label("zone", "zone2").Label("node", "node-x").Obj(),
 			},
-			wantNodeNameMap: map[string]int32{
+			wantNodeNameSet: map[string]struct{}{
-				"node-a": 0,
+				"node-a": {},
-				"node-b": 0,
+				"node-b": {},
-				"node-x": 0,
+				"node-x": {},
 			},
-			wantTopologyPairMap: map[topologyPair]*int32{
+			wantTopologyPairMap: map[topologyPair]*int64{
-				{key: "zone", value: "zone1"}:  new(int32),
+				{key: "zone", value: "zone1"}:  new(int64),
-				{key: "zone", value: "zone2"}:  new(int32),
+				{key: "zone", value: "zone2"}:  new(int64),
-				{key: "node", value: "node-a"}: new(int32),
+				{key: "node", value: "node-a"}: new(int64),
-				{key: "node", value: "node-b"}: new(int32),
+				{key: "node", value: "node-b"}: new(int64),
-				{key: "node", value: "node-x"}: new(int32),
+				{key: "node", value: "node-x"}: new(int64),
 			},
 		},
 		{
@@ -69,26 +69,26 @@ func Test_topologySpreadConstraintsMap_initialize(t *testing.T) {
 				st.MakeNode().Name("node-b").Label("zone", "zone1").Label("node", "node-b").Obj(),
 				st.MakeNode().Name("node-x").Label("node", "node-x").Obj(),
 			},
-			wantNodeNameMap: map[string]int32{
+			wantNodeNameSet: map[string]struct{}{
-				"node-a": 0,
+				"node-a": {},
-				"node-b": 0,
+				"node-b": {},
 			},
-			wantTopologyPairMap: map[topologyPair]*int32{
+			wantTopologyPairMap: map[topologyPair]*int64{
-				{key: "zone", value: "zone1"}:  new(int32),
+				{key: "zone", value: "zone1"}:  new(int64),
-				{key: "node", value: "node-a"}: new(int32),
+				{key: "node", value: "node-a"}: new(int64),
-				{key: "node", value: "node-b"}: new(int32),
+				{key: "node", value: "node-b"}: new(int64),
 			},
 		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			tMap := newTopologySpreadConstraintsMap()
+			m := newTopologySpreadConstraintsMap()
-			tMap.initialize(tt.pod, tt.nodes)
+			m.initialize(tt.pod, tt.nodes)
-			if !reflect.DeepEqual(tMap.nodeNameToPodCounts, tt.wantNodeNameMap) {
+			if !reflect.DeepEqual(m.nodeNameSet, tt.wantNodeNameSet) {
-				t.Errorf("initilize().nodeNameToPodCounts = %#v, want %#v", tMap.nodeNameToPodCounts, tt.wantNodeNameMap)
+				t.Errorf("initilize().nodeNameSet = %#v, want %#v", m.nodeNameSet, tt.wantNodeNameSet)
 			}
-			if !reflect.DeepEqual(tMap.topologyPairToPodCounts, tt.wantTopologyPairMap) {
+			if !reflect.DeepEqual(m.topologyPairToPodCounts, tt.wantTopologyPairMap) {
-				t.Errorf("initilize().topologyPairToPodCounts = %#v, want %#v", tMap.topologyPairToPodCounts, tt.wantTopologyPairMap)
+				t.Errorf("initilize().topologyPairToPodCounts = %#v, want %#v", m.topologyPairToPodCounts, tt.wantTopologyPairMap)
 			}
 		})
 	}
@@ -435,9 +435,23 @@ func TestCalculateEvenPodsSpreadPriority(t *testing.T) {
 			allNodes := append([]*v1.Node{}, tt.nodes...)
 			allNodes = append(allNodes, tt.failedNodes...)
 			snapshot := nodeinfosnapshot.NewSnapshot(tt.existingPods, allNodes)
-			got, _ := CalculateEvenPodsSpreadPriority(tt.pod, snapshot, tt.nodes)
+
-			if !reflect.DeepEqual(got, tt.want) {
+			meta := &priorityMetadata{
-				t.Errorf("CalculateEvenPodsSpreadPriority() = %#v, want %#v", got, tt.want)
+				podTopologySpreadMap: buildPodTopologySpreadMap(tt.pod, tt.nodes, snapshot.NodeInfoList),
+			}
+			var gotList framework.NodeScoreList
+			for _, n := range tt.nodes {
+				nodeName := n.Name
+				nodeScore, err := CalculateEvenPodsSpreadPriorityMap(tt.pod, meta, snapshot.NodeInfoMap[nodeName])
+				if err != nil {
+					t.Error(err)
+				}
+				gotList = append(gotList, nodeScore)
+			}
+
+			CalculateEvenPodsSpreadPriorityReduce(tt.pod, meta, snapshot, gotList)
+			if !reflect.DeepEqual(gotList, tt.want) {
+				t.Errorf("CalculateEvenPodsSpreadPriorityReduce() = %#v, want %#v", gotList, tt.want)
 			}
 		})
 	}
@@ -484,9 +498,19 @@ func BenchmarkTestCalculateEvenPodsSpreadPriority(b *testing.B) {
 		b.Run(tt.name, func(b *testing.B) {
 			existingPods, allNodes, filteredNodes := st.MakeNodesAndPodsForEvenPodsSpread(tt.pod, tt.existingPodsNum, tt.allNodesNum, tt.filteredNodesNum)
 			snapshot := nodeinfosnapshot.NewSnapshot(existingPods, allNodes)
+			meta := &priorityMetadata{
+				podTopologySpreadMap: buildPodTopologySpreadMap(tt.pod, filteredNodes, snapshot.NodeInfoList),
+			}
 			b.ResetTimer()
+
 			for i := 0; i < b.N; i++ {
-				CalculateEvenPodsSpreadPriority(tt.pod, snapshot, filteredNodes)
+				var gotList framework.NodeScoreList
+				for _, n := range filteredNodes {
+					nodeName := n.Name
+					nodeScore, _ := CalculateEvenPodsSpreadPriorityMap(tt.pod, meta, snapshot.NodeInfoMap[nodeName])
+					gotList = append(gotList, nodeScore)
+				}
+				CalculateEvenPodsSpreadPriorityReduce(tt.pod, meta, snapshot, gotList)
 			}
 		})
 	}

pkg/scheduler/algorithm/priorities/metadata.go

@@ -59,18 +59,21 @@ type priorityMetadata struct {
 	controllerRef           *metav1.OwnerReference
 	podFirstServiceSelector labels.Selector
 	totalNumNodes           int
+	podTopologySpreadMap    *podTopologySpreadMap
 }
 
 // PriorityMetadata is a PriorityMetadataProducer.  Node info can be nil.
-func (pmf *PriorityMetadataFactory) PriorityMetadata(pod *v1.Pod, _ []*v1.Node, sharedLister schedulerlisters.SharedLister) interface{} {
+func (pmf *PriorityMetadataFactory) PriorityMetadata(pod *v1.Pod, filteredNodes []*v1.Node, sharedLister schedulerlisters.SharedLister) interface{} {
 	// If we cannot compute metadata, just return nil
 	if pod == nil {
 		return nil
 	}
 	totalNumNodes := 0
+	var allNodes []*schedulernodeinfo.NodeInfo
 	if sharedLister != nil {
 		if l, err := sharedLister.NodeInfos().List(); err == nil {
 			totalNumNodes = len(l)
+			allNodes = l
 		}
 	}
 	return &priorityMetadata{
@@ -81,6 +84,7 @@ func (pmf *PriorityMetadataFactory) PriorityMetadata(pod *v1.Pod, _ []*v1.Node,
 		controllerRef:           metav1.GetControllerOf(pod),
 		podFirstServiceSelector: getFirstServiceSelector(pod, pmf.serviceLister),
 		totalNumNodes:           totalNumNodes,
+		podTopologySpreadMap:    buildPodTopologySpreadMap(pod, filteredNodes, allNodes),
 	}
 }
 

pkg/scheduler/algorithmprovider/defaults/defaults.go

@@ -68,7 +68,12 @@ func ApplyFeatureGates() (restore func()) {
 		scheduler.RegisterFitPredicate(predicates.EvenPodsSpreadPred, predicates.EvenPodsSpreadPredicate)
 		// register priority
 		scheduler.InsertPriorityKeyToAlgorithmProviderMap(priorities.EvenPodsSpreadPriority)
-		scheduler.RegisterPriorityFunction(priorities.EvenPodsSpreadPriority, priorities.CalculateEvenPodsSpreadPriority, 1)
+		scheduler.RegisterPriorityMapReduceFunction(
+			priorities.EvenPodsSpreadPriority,
+			priorities.CalculateEvenPodsSpreadPriorityMap,
+			priorities.CalculateEvenPodsSpreadPriorityReduce,
+			1,
+		)
 	}
 
 	// Prioritizes nodes that satisfy pod's resource limits

pkg/scheduler/api/compatibility/compatibility_test.go

@@ -1196,15 +1196,15 @@ func TestCompatibility_v1_Scheduler(t *testing.T) {
 			featureGates: map[featuregate.Feature]bool{
 				features.EvenPodsSpread: true,
 			},
-			wantPrioritizers: sets.NewString(
-				"EvenPodsSpreadPriority",
-			),
 			wantPlugins: map[string][]kubeschedulerconfig.Plugin{
 				"FilterPlugin": {
 					{Name: "NodeUnschedulable"},
 					{Name: "TaintToleration"},
 					{Name: "PodTopologySpread"},
 				},
+				"ScorePlugin": {
+					{Name: "PodTopologySpread", Weight: 2},
+				},
 			},
 		},
 		{

pkg/scheduler/framework/plugins/default_registry.go

@@ -229,25 +229,26 @@ func NewDefaultConfigProducerRegistry() *ConfigProducerRegistry {
 			plugins.Score = appendToPluginSet(plugins.Score, nodepreferavoidpods.Name, &args.Weight)
 			return
 		})
-
 	registry.RegisterPriority(priorities.MostRequestedPriority,
 		func(args ConfigProducerArgs) (plugins config.Plugins, pluginConfig []config.PluginConfig) {
 			plugins.Score = appendToPluginSet(plugins.Score, noderesources.MostAllocatedName, &args.Weight)
 			return
 		})
-
 	registry.RegisterPriority(priorities.BalancedResourceAllocation,
 		func(args ConfigProducerArgs) (plugins config.Plugins, pluginConfig []config.PluginConfig) {
 			plugins.Score = appendToPluginSet(plugins.Score, noderesources.BalancedAllocationName, &args.Weight)
 			return
 		})
-
 	registry.RegisterPriority(priorities.LeastRequestedPriority,
 		func(args ConfigProducerArgs) (plugins config.Plugins, pluginConfig []config.PluginConfig) {
 			plugins.Score = appendToPluginSet(plugins.Score, noderesources.LeastAllocatedName, &args.Weight)
 			return
 		})
-
+	registry.RegisterPriority(priorities.EvenPodsSpreadPriority,
+		func(args ConfigProducerArgs) (plugins config.Plugins, pluginConfig []config.PluginConfig) {
+			plugins.Score = appendToPluginSet(plugins.Score, podtopologyspread.Name, &args.Weight)
+			return
+		})
 	registry.RegisterPriority(requestedtocapacityratio.Name,
 		func(args ConfigProducerArgs) (plugins config.Plugins, pluginConfig []config.PluginConfig) {
 			plugins.Score = appendToPluginSet(plugins.Score, requestedtocapacityratio.Name, &args.Weight)

pkg/scheduler/framework/plugins/podtopologyspread/BUILD

@@ -7,6 +7,7 @@ go_library(
     visibility = ["//visibility:public"],
     deps = [
         "//pkg/scheduler/algorithm/predicates:go_default_library",
+        "//pkg/scheduler/algorithm/priorities:go_default_library",
         "//pkg/scheduler/framework/plugins/migration:go_default_library",
         "//pkg/scheduler/framework/v1alpha1:go_default_library",
         "//pkg/scheduler/nodeinfo:go_default_library",

pkg/scheduler/framework/plugins/podtopologyspread/pod_topology_spread.go

@@ -23,15 +23,19 @@ import (
 	"k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/kubernetes/pkg/scheduler/algorithm/predicates"
+	"k8s.io/kubernetes/pkg/scheduler/algorithm/priorities"
 	"k8s.io/kubernetes/pkg/scheduler/framework/plugins/migration"
 	framework "k8s.io/kubernetes/pkg/scheduler/framework/v1alpha1"
 	"k8s.io/kubernetes/pkg/scheduler/nodeinfo"
 )
 
 // PodTopologySpread is a plugin that ensures pod's topologySpreadConstraints is satisfied.
-type PodTopologySpread struct{}
+type PodTopologySpread struct {
+	handle framework.FrameworkHandle
+}
 
 var _ framework.FilterPlugin = &PodTopologySpread{}
+var _ framework.ScorePlugin = &PodTopologySpread{}
 
 // Name is the name of the plugin used in the plugin registry and configurations.
 const Name = "PodTopologySpread"
@@ -51,7 +55,33 @@ func (pl *PodTopologySpread) Filter(ctx context.Context, cycleState *framework.C
 	return migration.PredicateResultToFrameworkStatus(reasons, err)
 }
 
-// New initializes a new plugin and returns it.
+// Score invoked at the Score extension point.
-func New(_ *runtime.Unknown, _ framework.FrameworkHandle) (framework.Plugin, error) {
+// The "score" returned in this function is the matching number of pods on the `nodeName`,
-	return &PodTopologySpread{}, nil
+// it is normalized later.
+func (pl *PodTopologySpread) Score(ctx context.Context, state *framework.CycleState, pod *v1.Pod, nodeName string) (int64, *framework.Status) {
+	nodeInfo, err := pl.handle.SnapshotSharedLister().NodeInfos().Get(nodeName)
+	if err != nil {
+		return 0, framework.NewStatus(framework.Error, fmt.Sprintf("getting node %q from Snapshot: %v", nodeName, err))
+	}
+
+	meta := migration.PriorityMetadata(state)
+	s, err := priorities.CalculateEvenPodsSpreadPriorityMap(pod, meta, nodeInfo)
+	return s.Score, migration.ErrorToFrameworkStatus(err)
+}
+
+// NormalizeScore invoked after scoring all nodes.
+func (pl *PodTopologySpread) NormalizeScore(ctx context.Context, state *framework.CycleState, pod *v1.Pod, scores framework.NodeScoreList) *framework.Status {
+	meta := migration.PriorityMetadata(state)
+	err := priorities.CalculateEvenPodsSpreadPriorityReduce(pod, meta, pl.handle.SnapshotSharedLister(), scores)
+	return migration.ErrorToFrameworkStatus(err)
+}
+
+// ScoreExtensions of the Score plugin.
+func (pl *PodTopologySpread) ScoreExtensions() framework.ScoreExtensions {
+	return pl
+}
+
+// New initializes a new plugin and returns it.
+func New(_ *runtime.Unknown, h framework.FrameworkHandle) (framework.Plugin, error) {
+	return &PodTopologySpread{handle: h}, nil
 }

pkg/scheduler/framework/plugins/podtopologyspread/pod_topology_spread_test.go

@@ -23,14 +23,16 @@ import (
 	"k8s.io/api/core/v1"
 	"k8s.io/kubernetes/pkg/scheduler/algorithm/predicates"
 	"k8s.io/kubernetes/pkg/scheduler/framework/plugins/migration"
-	"k8s.io/kubernetes/pkg/scheduler/framework/v1alpha1"
+	framework "k8s.io/kubernetes/pkg/scheduler/framework/v1alpha1"
 	nodeinfosnapshot "k8s.io/kubernetes/pkg/scheduler/nodeinfo/snapshot"
 	st "k8s.io/kubernetes/pkg/scheduler/testing"
 )
 
-var hardSpread = v1.DoNotSchedule
+var (
+	hardSpread = v1.DoNotSchedule
+)
 
-func TestPodTopologySpreadFilter_SingleConstraint(t *testing.T) {
+func TestPodTopologySpread_Filter_SingleConstraint(t *testing.T) {
 	tests := []struct {
 		name         string
 		pod          *v1.Pod
@@ -269,7 +271,7 @@ func TestPodTopologySpreadFilter_SingleConstraint(t *testing.T) {
 		t.Run(tt.name, func(t *testing.T) {
 			snapshot := nodeinfosnapshot.NewSnapshot(tt.existingPods, tt.nodes)
 			meta := predicates.GetPredicateMetadata(tt.pod, snapshot)
-			state := v1alpha1.NewCycleState()
+			state := framework.NewCycleState()
 			state.Write(migration.PredicatesStateKey, &migration.PredicatesStateData{Reference: meta})
 			plugin, _ := New(nil, nil)
 			for _, node := range tt.nodes {
@@ -283,7 +285,7 @@ func TestPodTopologySpreadFilter_SingleConstraint(t *testing.T) {
 	}
 }
 
-func TestPodTopologySpreadFilter_MultipleConstraints(t *testing.T) {
+func TestPodTopologySpread_Filter_MultipleConstraints(t *testing.T) {
 	tests := []struct {
 		name         string
 		pod          *v1.Pod
@@ -466,7 +468,7 @@ func TestPodTopologySpreadFilter_MultipleConstraints(t *testing.T) {
 		t.Run(tt.name, func(t *testing.T) {
 			snapshot := nodeinfosnapshot.NewSnapshot(tt.existingPods, tt.nodes)
 			meta := predicates.GetPredicateMetadata(tt.pod, snapshot)
-			state := v1alpha1.NewCycleState()
+			state := framework.NewCycleState()
 			state.Write(migration.PredicatesStateKey, &migration.PredicatesStateData{Reference: meta})
 			plugin, _ := New(nil, nil)
 			for _, node := range tt.nodes {