adjust the Priority of General and Accurate Estimator of Karmada Scheduler

Signed-off-by: chaosi-zju <[email protected]>

Author: chaosi-zju

pkg/estimator/client/accurate.go

@@ -67,6 +67,10 @@ func (se *SchedulerEstimator) MaxAvailableReplicas(
 	})
 }
 
+func (se *SchedulerEstimator) GetPriority() EstimatorPriority {
+	return High
+}
+
 // GetUnschedulableReplicas gets the unschedulable replicas which belong to a specified workload by calling karmada-scheduler-estimator.
 func (se *SchedulerEstimator) GetUnschedulableReplicas(
 	parentCtx context.Context,

pkg/estimator/client/general.go

@@ -53,6 +53,10 @@ func (ge *GeneralEstimator) MaxAvailableReplicas(_ context.Context, clusters []*
 	return availableTargetClusters, nil
 }
 
+func (ge *GeneralEstimator) GetPriority() EstimatorPriority {
+	return Middle
+}
+
 func (ge *GeneralEstimator) maxAvailableReplicas(cluster *clusterv1alpha1.Cluster, replicaRequirements *workv1alpha2.ReplicaRequirements) int32 {
 	resourceSummary := cluster.Status.ResourceSummary
 	if resourceSummary == nil {

pkg/estimator/client/interface.go

@@ -37,6 +37,7 @@ var (
 // ReplicaEstimator is an estimator which estimates the maximum replicas that can be applied to the target cluster.
 type ReplicaEstimator interface {
 	MaxAvailableReplicas(ctx context.Context, clusters []*clusterv1alpha1.Cluster, replicaRequirements *workv1alpha2.ReplicaRequirements) ([]workv1alpha2.TargetCluster, error)
+	GetPriority() EstimatorPriority
 }
 
 // UnschedulableReplicaEstimator is an estimator which estimates the unschedulable replicas which belong to a specified workload.
@@ -53,3 +54,16 @@ func GetReplicaEstimators() map[string]ReplicaEstimator {
 func GetUnschedulableReplicaEstimators() map[string]UnschedulableReplicaEstimator {
 	return unschedulableReplicaEstimators
 }
+
+// EstimatorPriority
+// 1. Higher-priority estimator can directly override the result given by lower-priority estimator
+// 2. Lower replicas estimated will be chosen if the priority of estimator are same
+// 3. Lower-priority estimator would be ignored if the result was already given by higher-priority estimator
+type EstimatorPriority int
+
+const (
+	Undefined EstimatorPriority = iota
+	Low
+	Middle
+	High
+)

pkg/scheduler/core/util.go

@@ -53,13 +53,22 @@ func getDefaultWeightPreference(clusters []*clusterv1alpha1.Cluster) *policyv1al
 
 func calAvailableReplicas(clusters []*clusterv1alpha1.Cluster, spec *workv1alpha2.ResourceBindingSpec) []workv1alpha2.TargetCluster {
 	availableTargetClusters := make([]workv1alpha2.TargetCluster, len(clusters))
+	// availableResultPriority indicates which priority Estimator gives the scheduling result for each cluster, respectively
+	// 1. Higher-priority estimator can directly override the result given by lower-priority estimator
+	// 2. Lower replicas estimated will be chosen if the priority of estimator are same
+	// 3. Lower-priority estimator would be ignored if the result was already given by higher-priority estimator
+	availableResultPriority := make([]estimatorclient.EstimatorPriority, len(clusters))
 
 	// Set the boundary.
 	for i := range availableTargetClusters {
 		availableTargetClusters[i].Name = clusters[i].Name
 		availableTargetClusters[i].Replicas = math.MaxInt32
 	}
 
+	for i := range availableResultPriority {
+		availableResultPriority[i] = estimatorclient.Undefined
+	}
+
 	// For non-workload, like ServiceAccount, ConfigMap, Secret and etc, it's unnecessary to calculate available replicas in member clusters.
 	// See issue: https://github.com/karmada-io/karmada/issues/3743.
 	if spec.Replicas == 0 {
@@ -79,11 +88,21 @@ func calAvailableReplicas(clusters []*clusterv1alpha1.Cluster, spec *workv1alpha
 			continue
 		}
 		for i := range res {
+			if res[i].Name != availableTargetClusters[i].Name {
+				continue
+			}
 			if res[i].Replicas == estimatorclient.UnauthenticReplica {
 				continue
 			}
-			if availableTargetClusters[i].Name == res[i].Name && availableTargetClusters[i].Replicas > res[i].Replicas {
+			// means there are already replicas calculated by higher-priority estimator
+			if estimator.GetPriority() < availableResultPriority[i] {
+				continue
+			}
+			// override if current estimator has higher priority and take lower replicas is estimator priority are same
+			if (estimator.GetPriority() == availableResultPriority[i] && res[i].Replicas < availableTargetClusters[i].Replicas) ||
+				estimator.GetPriority() > availableResultPriority[i] {
 				availableTargetClusters[i].Replicas = res[i].Replicas
+				availableResultPriority[i] = estimator.GetPriority()
 			}
 		}
 	}