Merge pull request #4586 from jwcesign/dev

fix: reschedule the replicas of the disappear clusters in PP

pkg/scheduler/core/assignment.go

@@ -90,7 +90,21 @@ func newAssignState(candidates []*clusterv1alpha1.Cluster, placement *policyv1al
 }
 
 func (as *assignState) buildScheduledClusters() {
-	as.scheduledClusters = as.spec.Clusters
+	candidateClusterSet := sets.Set[string]{}
+	for _, c := range as.candidates {
+		candidateClusterSet.Insert(c.Name)
+	}
+	as.scheduledClusters = []workv1alpha2.TargetCluster{}
+	for _, c := range as.spec.Clusters {
+		// Ignore clusters that are no longer candidates, to ensure we can get real
+		// 'assigned' replicas from the previous schedule result. The ignored replicas
+		// will be treated as scaled-up replicas that will be assigned to other
+		// candidate clusters.
+		if !candidateClusterSet.Has(c.Name) {
+			continue
+		}
+		as.scheduledClusters = append(as.scheduledClusters, c)
+	}
 	as.assignedReplicas = util.GetSumOfReplicas(as.scheduledClusters)
 }
 

pkg/scheduler/core/assignment_test.go

@@ -580,8 +580,8 @@ func Test_dynamicScale(t *testing.T) {
 			},
 			want: []workv1alpha2.TargetCluster{
 				{Name: ClusterMember1, Replicas: 7},
-				{Name: ClusterMember2, Replicas: 8},
-				{Name: ClusterMember4, Replicas: 9},
+				{Name: ClusterMember3, Replicas: 6},
+				{Name: ClusterMember4, Replicas: 11},
 			},
 			wantErr: false,
 		},
@@ -785,6 +785,37 @@ func Test_dynamicScaleUp(t *testing.T) {
 			},
 			wantErr: true,
 		},
+		{
+			name: "replica 12, dynamic weight 3:3, with cluster3 disappeared and cluster2 appeared",
+			candidates: []*clusterv1alpha1.Cluster{
+				helper.NewClusterWithResource(ClusterMember1, corev1.ResourceList{
+					corev1.ResourcePods: *resource.NewQuantity(3, resource.DecimalSI),
+				}, util.EmptyResource().ResourceList(), util.EmptyResource().ResourceList()),
+				helper.NewClusterWithResource(ClusterMember2, corev1.ResourceList{
+					corev1.ResourcePods: *resource.NewQuantity(3, resource.DecimalSI),
+				}, util.EmptyResource().ResourceList(), util.EmptyResource().ResourceList()),
+			},
+			object: &workv1alpha2.ResourceBindingSpec{
+				ReplicaRequirements: &workv1alpha2.ReplicaRequirements{
+					ResourceRequest: util.EmptyResource().ResourceList(),
+				},
+				Clusters: []workv1alpha2.TargetCluster{
+					{Name: ClusterMember1, Replicas: 6},
+					{Name: ClusterMember3, Replicas: 6},
+				},
+				Replicas: 12,
+			},
+			placement: &policyv1alpha1.Placement{
+				ReplicaScheduling: dynamicWeightStrategy,
+			},
+			wants: [][]workv1alpha2.TargetCluster{
+				{
+					{Name: ClusterMember1, Replicas: 9},
+					{Name: ClusterMember2, Replicas: 3},
+				},
+			},
+			wantErr: false,
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {