karmada/pkg/scheduler/core/generic_scheduler.go

647 lines
25 KiB
Go

package core
import (
"context"
"fmt"
"math"
"sort"
corev1 "k8s.io/api/core/v1"
"k8s.io/apimachinery/pkg/util/sets"
"k8s.io/klog/v2"
clusterv1alpha1 "github.com/karmada-io/karmada/pkg/apis/cluster/v1alpha1"
policyv1alpha1 "github.com/karmada-io/karmada/pkg/apis/policy/v1alpha1"
workv1alpha1 "github.com/karmada-io/karmada/pkg/apis/work/v1alpha1"
lister "github.com/karmada-io/karmada/pkg/generated/listers/policy/v1alpha1"
"github.com/karmada-io/karmada/pkg/scheduler/cache"
"github.com/karmada-io/karmada/pkg/scheduler/framework"
"github.com/karmada-io/karmada/pkg/scheduler/framework/runtime"
"github.com/karmada-io/karmada/pkg/util"
"github.com/karmada-io/karmada/pkg/util/helper"
)
// ScheduleAlgorithm is the interface that should be implemented to schedule a resource to the target clusters.
type ScheduleAlgorithm interface {
Schedule(context.Context, *policyv1alpha1.Placement, *workv1alpha1.ResourceBindingSpec) (scheduleResult ScheduleResult, err error)
ScaleSchedule(context.Context, *policyv1alpha1.Placement, *workv1alpha1.ResourceBindingSpec) (scheduleResult ScheduleResult, err error)
FailoverSchedule(context.Context, *policyv1alpha1.Placement, *workv1alpha1.ResourceBindingSpec) (scheduleResult ScheduleResult, err error)
}
// ScheduleResult includes the clusters selected.
type ScheduleResult struct {
SuggestedClusters []workv1alpha1.TargetCluster
}
type genericScheduler struct {
schedulerCache cache.Cache
// TODO: move it into schedulerCache
policyLister lister.PropagationPolicyLister
scheduleFramework framework.Framework
}
// NewGenericScheduler creates a genericScheduler object.
func NewGenericScheduler(
schedCache cache.Cache,
policyLister lister.PropagationPolicyLister,
plugins []string,
) ScheduleAlgorithm {
return &genericScheduler{
schedulerCache: schedCache,
policyLister: policyLister,
scheduleFramework: runtime.NewFramework(plugins),
}
}
func (g *genericScheduler) Schedule(ctx context.Context, placement *policyv1alpha1.Placement, spec *workv1alpha1.ResourceBindingSpec) (result ScheduleResult, err error) {
clusterInfoSnapshot := g.schedulerCache.Snapshot()
if clusterInfoSnapshot.NumOfClusters() == 0 {
return result, fmt.Errorf("no clusters available to schedule")
}
feasibleClusters, err := g.findClustersThatFit(ctx, g.scheduleFramework, placement, &spec.Resource, clusterInfoSnapshot)
if err != nil {
return result, fmt.Errorf("failed to findClustersThatFit: %v", err)
}
if len(feasibleClusters) == 0 {
return result, fmt.Errorf("no clusters fit")
}
klog.V(4).Infof("feasible clusters found: %v", feasibleClusters)
clustersScore, err := g.prioritizeClusters(ctx, g.scheduleFramework, placement, feasibleClusters)
if err != nil {
return result, fmt.Errorf("failed to prioritizeClusters: %v", err)
}
klog.V(4).Infof("feasible clusters scores: %v", clustersScore)
clusters := g.selectClusters(clustersScore, placement.SpreadConstraints, feasibleClusters)
clustersWithReplicas, err := g.assignReplicas(clusters, placement.ReplicaScheduling, spec)
if err != nil {
return result, fmt.Errorf("failed to assignReplicas: %v", err)
}
result.SuggestedClusters = clustersWithReplicas
return result, nil
}
// findClustersThatFit finds the clusters that are fit for the placement based on running the filter plugins.
func (g *genericScheduler) findClustersThatFit(
ctx context.Context,
fwk framework.Framework,
placement *policyv1alpha1.Placement,
resource *workv1alpha1.ObjectReference,
clusterInfo *cache.Snapshot) ([]*clusterv1alpha1.Cluster, error) {
var out []*clusterv1alpha1.Cluster
clusters := clusterInfo.GetReadyClusters()
for _, c := range clusters {
resMap := fwk.RunFilterPlugins(ctx, placement, resource, c.Cluster())
res := resMap.Merge()
if !res.IsSuccess() {
klog.V(4).Infof("cluster %q is not fit", c.Cluster().Name)
} else {
out = append(out, c.Cluster())
}
}
return out, nil
}
// prioritizeClusters prioritize the clusters by running the score plugins.
func (g *genericScheduler) prioritizeClusters(
ctx context.Context,
fwk framework.Framework,
placement *policyv1alpha1.Placement,
clusters []*clusterv1alpha1.Cluster) (result framework.ClusterScoreList, err error) {
scoresMap, err := fwk.RunScorePlugins(ctx, placement, clusters)
if err != nil {
return result, err
}
result = make(framework.ClusterScoreList, len(clusters))
for i := range clusters {
result[i] = framework.ClusterScore{Name: clusters[i].Name, Score: 0}
for j := range scoresMap {
result[i].Score += scoresMap[j][i].Score
}
}
return result, nil
}
func (g *genericScheduler) selectClusters(clustersScore framework.ClusterScoreList, spreadConstraints []policyv1alpha1.SpreadConstraint, clusters []*clusterv1alpha1.Cluster) []*clusterv1alpha1.Cluster {
if len(spreadConstraints) != 0 {
return g.matchSpreadConstraints(clusters, spreadConstraints)
}
return clusters
}
func (g *genericScheduler) matchSpreadConstraints(clusters []*clusterv1alpha1.Cluster, spreadConstraints []policyv1alpha1.SpreadConstraint) []*clusterv1alpha1.Cluster {
state := util.NewSpreadGroup()
g.runSpreadConstraintsFilter(clusters, spreadConstraints, state)
return g.calSpreadResult(state)
}
// Now support spread by cluster. More rules will be implemented later.
func (g *genericScheduler) runSpreadConstraintsFilter(clusters []*clusterv1alpha1.Cluster, spreadConstraints []policyv1alpha1.SpreadConstraint, spreadGroup *util.SpreadGroup) {
for _, spreadConstraint := range spreadConstraints {
spreadGroup.InitialGroupRecord(spreadConstraint)
if spreadConstraint.SpreadByField == policyv1alpha1.SpreadByFieldCluster {
g.groupByFieldCluster(clusters, spreadConstraint, spreadGroup)
}
}
}
func (g *genericScheduler) groupByFieldCluster(clusters []*clusterv1alpha1.Cluster, spreadConstraint policyv1alpha1.SpreadConstraint, spreadGroup *util.SpreadGroup) {
for _, cluster := range clusters {
clusterGroup := cluster.Name
spreadGroup.GroupRecord[spreadConstraint][clusterGroup] = append(spreadGroup.GroupRecord[spreadConstraint][clusterGroup], cluster)
}
}
func (g *genericScheduler) calSpreadResult(spreadGroup *util.SpreadGroup) []*clusterv1alpha1.Cluster {
// TODO: now support single spread constraint
if len(spreadGroup.GroupRecord) > 1 {
return nil
}
return g.chooseSpreadGroup(spreadGroup)
}
func (g *genericScheduler) chooseSpreadGroup(spreadGroup *util.SpreadGroup) []*clusterv1alpha1.Cluster {
var feasibleClusters []*clusterv1alpha1.Cluster
for spreadConstraint, clusterGroups := range spreadGroup.GroupRecord {
if spreadConstraint.SpreadByField == policyv1alpha1.SpreadByFieldCluster {
if len(clusterGroups) < spreadConstraint.MinGroups {
return nil
}
if len(clusterGroups) <= spreadConstraint.MaxGroups {
for _, v := range clusterGroups {
feasibleClusters = append(feasibleClusters, v...)
}
break
}
if spreadConstraint.MaxGroups > 0 && len(clusterGroups) > spreadConstraint.MaxGroups {
var groups []string
for group := range clusterGroups {
groups = append(groups, group)
}
for i := 0; i < spreadConstraint.MaxGroups; i++ {
feasibleClusters = append(feasibleClusters, clusterGroups[groups[i]]...)
}
}
}
}
return feasibleClusters
}
func (g *genericScheduler) assignReplicas(clusters []*clusterv1alpha1.Cluster, replicaSchedulingStrategy *policyv1alpha1.ReplicaSchedulingStrategy, object *workv1alpha1.ResourceBindingSpec) ([]workv1alpha1.TargetCluster, error) {
if len(clusters) == 0 {
return nil, fmt.Errorf("no clusters available to schedule")
}
targetClusters := make([]workv1alpha1.TargetCluster, len(clusters))
if object.Replicas > 0 && replicaSchedulingStrategy != nil {
if replicaSchedulingStrategy.ReplicaSchedulingType == policyv1alpha1.ReplicaSchedulingTypeDuplicated {
for i, cluster := range clusters {
targetClusters[i] = workv1alpha1.TargetCluster{Name: cluster.Name, Replicas: object.Replicas}
}
return targetClusters, nil
}
if replicaSchedulingStrategy.ReplicaSchedulingType == policyv1alpha1.ReplicaSchedulingTypeDivided {
if replicaSchedulingStrategy.ReplicaDivisionPreference == policyv1alpha1.ReplicaDivisionPreferenceWeighted {
if replicaSchedulingStrategy.WeightPreference == nil {
// if ReplicaDivisionPreference is set to "Weighted" and WeightPreference is not set, scheduler will weight all clusters the same.
replicaSchedulingStrategy.WeightPreference = getDefaultWeightPreference(clusters)
}
return g.divideReplicasByStaticWeight(clusters, replicaSchedulingStrategy.WeightPreference.StaticWeightList, object.Replicas)
}
if replicaSchedulingStrategy.ReplicaDivisionPreference == policyv1alpha1.ReplicaDivisionPreferenceAggregated {
return g.divideReplicasAggregatedWithResource(clusters, object)
}
// will never reach here, only "Aggregated" and "Weighted" are support
return nil, nil
}
}
for i, cluster := range clusters {
targetClusters[i] = workv1alpha1.TargetCluster{Name: cluster.Name}
}
return targetClusters, nil
}
func getDefaultWeightPreference(clusters []*clusterv1alpha1.Cluster) *policyv1alpha1.ClusterPreferences {
staticWeightLists := make([]policyv1alpha1.StaticClusterWeight, 0)
for _, cluster := range clusters {
staticWeightList := policyv1alpha1.StaticClusterWeight{
TargetCluster: policyv1alpha1.ClusterAffinity{
ClusterNames: []string{cluster.Name},
},
Weight: 1,
}
staticWeightLists = append(staticWeightLists, staticWeightList)
}
return &policyv1alpha1.ClusterPreferences{
StaticWeightList: staticWeightLists,
}
}
// divideReplicasByStaticWeight assigns a total number of replicas to the selected clusters by the weight list.
func (g *genericScheduler) divideReplicasByStaticWeight(clusters []*clusterv1alpha1.Cluster, staticWeightList []policyv1alpha1.StaticClusterWeight, replicas int32) ([]workv1alpha1.TargetCluster, error) {
weightSum := int64(0)
matchClusters := make(map[string]int64)
desireReplicaInfos := make(map[string]int64)
for _, cluster := range clusters {
for _, staticWeightRule := range staticWeightList {
if util.ClusterMatches(cluster, staticWeightRule.TargetCluster) {
weightSum += staticWeightRule.Weight
matchClusters[cluster.Name] = staticWeightRule.Weight
break
}
}
}
if weightSum == 0 {
for _, cluster := range clusters {
weightSum++
matchClusters[cluster.Name] = 1
}
}
allocatedReplicas := int32(0)
for clusterName, weight := range matchClusters {
desireReplicaInfos[clusterName] = weight * int64(replicas) / weightSum
allocatedReplicas += int32(desireReplicaInfos[clusterName])
}
if remainReplicas := replicas - allocatedReplicas; remainReplicas > 0 {
sortedClusters := helper.SortClusterByWeight(matchClusters)
for i := 0; remainReplicas > 0; i++ {
desireReplicaInfos[sortedClusters[i].ClusterName]++
remainReplicas--
if i == len(desireReplicaInfos) {
i = 0
}
}
}
for _, cluster := range clusters {
if _, exist := matchClusters[cluster.Name]; !exist {
desireReplicaInfos[cluster.Name] = 0
}
}
targetClusters := make([]workv1alpha1.TargetCluster, len(desireReplicaInfos))
i := 0
for key, value := range desireReplicaInfos {
targetClusters[i] = workv1alpha1.TargetCluster{Name: key, Replicas: int32(value)}
i++
}
return targetClusters, nil
}
// TargetClustersList is a slice of TargetCluster that implements sort.Interface to sort by Value.
type TargetClustersList []workv1alpha1.TargetCluster
func (a TargetClustersList) Len() int { return len(a) }
func (a TargetClustersList) Swap(i, j int) { a[i], a[j] = a[j], a[i] }
func (a TargetClustersList) Less(i, j int) bool { return a[i].Replicas > a[j].Replicas }
// divideReplicasAggregatedWithResource assigns a total number of replicas to the selected clusters aggregated according to the resource
func (g *genericScheduler) divideReplicasAggregatedWithResource(clusters []*clusterv1alpha1.Cluster, spec *workv1alpha1.ResourceBindingSpec,
preUsedClustersName ...string) ([]workv1alpha1.TargetCluster, error) {
// preUsedClustersName is used to prioritize the clusters
for _, value := range spec.ReplicaResourceRequirements {
if value.Value() > 0 {
return g.divideReplicasAggregatedWithResourceRequirements(clusters, spec, preUsedClustersName...)
}
}
return g.divideReplicasAggregatedWithoutResourceRequirements(clusters, spec, preUsedClustersName...)
}
func (g *genericScheduler) divideReplicasAggregatedWithoutResourceRequirements(clusters []*clusterv1alpha1.Cluster,
spec *workv1alpha1.ResourceBindingSpec, preUsedClustersName ...string) ([]workv1alpha1.TargetCluster, error) {
preUsedClusters, unUsedClusters := g.getPreUsed(clusters, preUsedClustersName...)
clusters = append(preUsedClusters, unUsedClusters...)
targetClusters := make([]workv1alpha1.TargetCluster, len(clusters))
for i, clusterInfo := range clusters {
targetClusters[i] = workv1alpha1.TargetCluster{Name: clusterInfo.Name, Replicas: 0}
}
targetClusters[0] = workv1alpha1.TargetCluster{Name: clusters[0].Name, Replicas: spec.Replicas}
return targetClusters, nil
}
func (g *genericScheduler) divideReplicasAggregatedWithResourceRequirements(clusters []*clusterv1alpha1.Cluster,
spec *workv1alpha1.ResourceBindingSpec, preUsedClustersName ...string) ([]workv1alpha1.TargetCluster, error) {
// make sure preUsedClusters are in front of the unUsedClusters in the list of clusterAvailableReplicas
// so that we can assign new replicas to them preferentially when scale up.
// preUsedClusters have none items during first scheduler
preUsedClusters, unUsedClusters := g.getPreUsed(clusters, preUsedClustersName...)
preUsedClustersAvailableReplicas := g.calAvailableReplicas(preUsedClusters, spec.ReplicaResourceRequirements)
unUsedClustersAvailableReplicas := g.calAvailableReplicas(unUsedClusters, spec.ReplicaResourceRequirements)
clusterAvailableReplicas := append(preUsedClustersAvailableReplicas, unUsedClustersAvailableReplicas...)
return g.divideReplicasAggregatedWithClusterReplicas(clusterAvailableReplicas, spec.Replicas)
}
func (g *genericScheduler) calAvailableReplicas(clusters []*clusterv1alpha1.Cluster, replicaResourceRequirements corev1.ResourceList) []workv1alpha1.TargetCluster {
availableTargetClusters := make([]workv1alpha1.TargetCluster, len(clusters))
for i, cluster := range clusters {
maxReplicas := g.calClusterAvailableReplicas(cluster, replicaResourceRequirements)
availableTargetClusters[i] = workv1alpha1.TargetCluster{Name: cluster.Name, Replicas: maxReplicas}
}
sort.Sort(TargetClustersList(availableTargetClusters))
return availableTargetClusters
}
// calClusterAvailableReplicas calculates how many replicas can be applied to the target cluster.
func (g *genericScheduler) calClusterAvailableReplicas(cluster *clusterv1alpha1.Cluster, resourcePerReplicas corev1.ResourceList) int32 {
var maximumReplicas int64 = math.MaxInt32
resourceSummary := cluster.Status.ResourceSummary
for key, value := range resourcePerReplicas {
requestedQuantity := value.Value()
if requestedQuantity <= 0 {
continue
}
// calculates available resource quantity
// available = allocatable - allocated - allocating
allocatable, ok := resourceSummary.Allocatable[key]
if !ok {
return 0
}
allocated, ok := resourceSummary.Allocated[key]
if ok {
allocatable.Sub(allocated)
}
allocating, ok := resourceSummary.Allocating[key]
if ok {
allocatable.Sub(allocating)
}
availableQuantity := allocatable.Value()
// short path: no more resource left.
if availableQuantity <= 0 {
return 0
}
if key == corev1.ResourceCPU {
requestedQuantity = value.MilliValue()
availableQuantity = allocatable.MilliValue()
}
maximumReplicasForResource := availableQuantity / requestedQuantity
if maximumReplicasForResource < maximumReplicas {
maximumReplicas = maximumReplicasForResource
}
}
return int32(maximumReplicas)
}
func (g *genericScheduler) divideReplicasAggregatedWithClusterReplicas(clusterAvailableReplicas []workv1alpha1.TargetCluster, replicas int32) ([]workv1alpha1.TargetCluster, error) {
clustersNum := 0
clustersMaxReplicas := int32(0)
for _, clusterInfo := range clusterAvailableReplicas {
clustersNum++
clustersMaxReplicas += clusterInfo.Replicas
if clustersMaxReplicas >= replicas {
break
}
}
if clustersMaxReplicas < replicas {
return nil, fmt.Errorf("clusters resources are not enough to schedule, max %v replicas are support", clustersMaxReplicas)
}
desireReplicaInfos := make(map[string]int32)
allocatedReplicas := int32(0)
for i, clusterInfo := range clusterAvailableReplicas {
if i >= clustersNum {
desireReplicaInfos[clusterInfo.Name] = 0
continue
}
desireReplicaInfos[clusterInfo.Name] = clusterInfo.Replicas * replicas / clustersMaxReplicas
allocatedReplicas += desireReplicaInfos[clusterInfo.Name]
}
if remainReplicas := replicas - allocatedReplicas; remainReplicas > 0 {
for i := 0; remainReplicas > 0; i++ {
desireReplicaInfos[clusterAvailableReplicas[i].Name]++
remainReplicas--
if i == clustersNum {
i = 0
}
}
}
targetClusters := make([]workv1alpha1.TargetCluster, len(clusterAvailableReplicas))
i := 0
for key, value := range desireReplicaInfos {
targetClusters[i] = workv1alpha1.TargetCluster{Name: key, Replicas: value}
i++
}
return targetClusters, nil
}
func (g *genericScheduler) ScaleSchedule(ctx context.Context, placement *policyv1alpha1.Placement,
spec *workv1alpha1.ResourceBindingSpec) (result ScheduleResult, err error) {
newTargetClusters := make([]workv1alpha1.TargetCluster, len(spec.Clusters))
if spec.Replicas > 0 {
if placement.ReplicaScheduling.ReplicaSchedulingType == policyv1alpha1.ReplicaSchedulingTypeDuplicated {
for i, cluster := range spec.Clusters {
newTargetClusters[i] = workv1alpha1.TargetCluster{Name: cluster.Name, Replicas: spec.Replicas}
}
result.SuggestedClusters = newTargetClusters
return result, nil
}
if placement.ReplicaScheduling.ReplicaSchedulingType == policyv1alpha1.ReplicaSchedulingTypeDivided {
if placement.ReplicaScheduling.ReplicaDivisionPreference == policyv1alpha1.ReplicaDivisionPreferenceWeighted {
preSelectedClusters := g.getPreSelected(spec.Clusters)
if placement.ReplicaScheduling.WeightPreference == nil {
// if ReplicaDivisionPreference is set to "Weighted" and WeightPreference is not set, scheduler will weight all clusters the same.
placement.ReplicaScheduling.WeightPreference = getDefaultWeightPreference(preSelectedClusters)
}
clustersWithReplicase, err := g.divideReplicasByStaticWeight(preSelectedClusters, placement.ReplicaScheduling.WeightPreference.StaticWeightList, spec.Replicas)
if err != nil {
return result, fmt.Errorf("failed to assignReplicas with Weight: %v", err)
}
result.SuggestedClusters = clustersWithReplicase
return result, nil
}
if placement.ReplicaScheduling.ReplicaDivisionPreference == policyv1alpha1.ReplicaDivisionPreferenceAggregated {
return g.scaleScheduleWithReplicaDivisionPreferenceAggregated(spec)
}
// will never reach here, only "Aggregated" and "Weighted" are support
return result, nil
}
}
for i, cluster := range spec.Clusters {
newTargetClusters[i] = workv1alpha1.TargetCluster{Name: cluster.Name}
}
result.SuggestedClusters = newTargetClusters
return result, nil
}
func (g *genericScheduler) scaleScheduleWithReplicaDivisionPreferenceAggregated(spec *workv1alpha1.ResourceBindingSpec) (result ScheduleResult, err error) {
assignedReplicas := util.GetSumOfReplicas(spec.Clusters)
if assignedReplicas > spec.Replicas {
newTargetClusters, err := g.scaleDownScheduleWithReplicaDivisionPreferenceAggregated(spec)
if err != nil {
return result, fmt.Errorf("failed to scaleDown: %v", err)
}
result.SuggestedClusters = newTargetClusters
} else if assignedReplicas < spec.Replicas {
newTargetClusters, err := g.scaleUpScheduleWithReplicaDivisionPreferenceAggregated(spec)
if err != nil {
return result, fmt.Errorf("failed to scaleUp: %v", err)
}
result.SuggestedClusters = newTargetClusters
} else {
result.SuggestedClusters = spec.Clusters
}
return result, nil
}
func (g *genericScheduler) scaleDownScheduleWithReplicaDivisionPreferenceAggregated(spec *workv1alpha1.ResourceBindingSpec) ([]workv1alpha1.TargetCluster, error) {
return g.divideReplicasAggregatedWithClusterReplicas(spec.Clusters, spec.Replicas)
}
func (g *genericScheduler) scaleUpScheduleWithReplicaDivisionPreferenceAggregated(spec *workv1alpha1.ResourceBindingSpec) ([]workv1alpha1.TargetCluster, error) {
// find the clusters that have old replicas so we can assign new replicas to them preferentially
// targetMap map of the result for the old replicas so that it can be merged with the new result easily
targetMap := make(map[string]int32)
usedTargetClusters := make([]string, 0)
assignedReplicas := int32(0)
for _, cluster := range spec.Clusters {
targetMap[cluster.Name] = cluster.Replicas
assignedReplicas += cluster.Replicas
if cluster.Replicas > 0 {
usedTargetClusters = append(usedTargetClusters, cluster.Name)
}
}
preSelected := g.getPreSelected(spec.Clusters)
// only the new replicas are considered during this scheduler, the old replicas will not be moved.
// if not the old replicas may be recreated which is not expected during scaling up
// use usedTargetClusters to make sure that we assign new replicas to them preferentially so that all the replicas are aggregated
newObject := spec.DeepCopy()
newObject.Replicas = spec.Replicas - assignedReplicas
result, err := g.divideReplicasAggregatedWithResource(preSelected, newObject, usedTargetClusters...)
if err != nil {
return result, err
}
// merge the result of this scheduler for new replicas and the data of old replicas
for i, cluster := range result {
value, ok := targetMap[cluster.Name]
if ok {
result[i].Replicas = cluster.Replicas + value
delete(targetMap, cluster.Name)
}
}
for key, value := range targetMap {
result = append(result, workv1alpha1.TargetCluster{Name: key, Replicas: value})
}
return result, nil
}
func (g *genericScheduler) getPreSelected(targetClusters []workv1alpha1.TargetCluster) []*clusterv1alpha1.Cluster {
var preSelectedClusters []*clusterv1alpha1.Cluster
clusterInfoSnapshot := g.schedulerCache.Snapshot()
for _, targetCluster := range targetClusters {
for _, cluster := range clusterInfoSnapshot.GetClusters() {
if targetCluster.Name == cluster.Cluster().Name {
preSelectedClusters = append(preSelectedClusters, cluster.Cluster())
break
}
}
}
return preSelectedClusters
}
func (g *genericScheduler) getPreUsed(clusters []*clusterv1alpha1.Cluster, preUsedClustersName ...string) ([]*clusterv1alpha1.Cluster, []*clusterv1alpha1.Cluster) {
if len(preUsedClustersName) == 0 {
return clusters, nil
}
preUsedClusterSet := sets.NewString(preUsedClustersName...)
var preUsedCluster []*clusterv1alpha1.Cluster
var unUsedCluster []*clusterv1alpha1.Cluster
for i := range clusters {
if preUsedClusterSet.Has(clusters[i].Name) {
preUsedCluster = append(preUsedCluster, clusters[i])
} else {
unUsedCluster = append(unUsedCluster, clusters[i])
}
}
return preUsedCluster, unUsedCluster
}
func (g *genericScheduler) FailoverSchedule(ctx context.Context, placement *policyv1alpha1.Placement,
spec *workv1alpha1.ResourceBindingSpec) (result ScheduleResult, err error) {
readyClusters := g.schedulerCache.Snapshot().GetReadyClusterNames()
totalClusters := util.ConvertToClusterNames(spec.Clusters)
reservedClusters := calcReservedCluster(totalClusters, readyClusters)
availableClusters := calcAvailableCluster(totalClusters, readyClusters)
candidateClusters := sets.NewString()
for clusterName := range availableClusters {
clusterObj := g.schedulerCache.Snapshot().GetCluster(clusterName)
if clusterObj == nil {
return result, fmt.Errorf("failed to get clusterObj by clusterName: %s", clusterName)
}
resMap := g.scheduleFramework.RunFilterPlugins(ctx, placement, &spec.Resource, clusterObj.Cluster())
res := resMap.Merge()
if !res.IsSuccess() {
klog.V(4).Infof("cluster %q is not fit", clusterName)
} else {
candidateClusters.Insert(clusterName)
}
}
klog.V(4).Infof("Reserved bindingClusters : %v", reservedClusters.List())
klog.V(4).Infof("Candidate bindingClusters: %v", candidateClusters.List())
// TODO: should schedule as much as possible?
deltaLen := len(spec.Clusters) - len(reservedClusters)
if len(candidateClusters) < deltaLen {
// for ReplicaSchedulingTypeDivided, we will try to migrate replicas to the other health clusters
if placement.ReplicaScheduling == nil || placement.ReplicaScheduling.ReplicaSchedulingType == policyv1alpha1.ReplicaSchedulingTypeDuplicated {
klog.Warningf("ignore reschedule binding as insufficient available cluster")
return ScheduleResult{}, nil
}
}
// TODO: check if the final result meets the spread constraints.
targetClusters := reservedClusters
clusterList := candidateClusters.List()
for i := 0; i < deltaLen && i < len(candidateClusters); i++ {
targetClusters.Insert(clusterList[i])
}
var reScheduleResult []workv1alpha1.TargetCluster
for cluster := range targetClusters {
reScheduleResult = append(reScheduleResult, workv1alpha1.TargetCluster{Name: cluster})
}
return ScheduleResult{reScheduleResult}, nil
}
// calcReservedCluster eliminates the not-ready clusters from the 'bindClusters'.
func calcReservedCluster(bindClusters, readyClusters sets.String) sets.String {
return bindClusters.Difference(bindClusters.Difference(readyClusters))
}
// calcAvailableCluster returns a list of ready clusters that not in 'bindClusters'.
func calcAvailableCluster(bindCluster, readyClusters sets.String) sets.String {
return readyClusters.Difference(bindCluster)
}