Merge pull request #790 from jiangkaihua/release-0.4

Add bestNodeFn for plugins to select best node of its own.

pkg/scheduler/actions/allocate/allocate.go

@@ -203,7 +203,11 @@ func (alloc *allocateAction) Execute(ssn *framework.Session) {
 
 			nodeScores := util.PrioritizeNodes(task, candidateNodes, ssn.BatchNodeOrderFn, ssn.NodeOrderMapFn, ssn.NodeOrderReduceFn)
 
-			node := util.SelectBestNode(nodeScores)
+			node := ssn.BestNodeFn(task, nodeScores)
+			if node == nil {
+				node = util.SelectBestNode(nodeScores)
+			}
+
 			// Allocate idle resource to the task.
 			if task.InitResreq.LessEqual(node.Idle) {
 				klog.V(3).Infof("Binding Task <%v/%v> to node <%v>",

pkg/scheduler/api/types.go

@@ -117,19 +117,22 @@ type CompareFn func(interface{}, interface{}) int
 // ValidateFn is the func declaration used to check object's status.
 type ValidateFn func(interface{}) bool
 
-// ValidateResult is struct to which can used to determine the result
+// ValidateResult is struct to which can used to determine the result.
 type ValidateResult struct {
 	Pass    bool
 	Reason  string
 	Message string
 }
 
-// ValidateExFn is the func declaration used to validate the result
+// ValidateExFn is the func declaration used to validate the result.
 type ValidateExFn func(interface{}) *ValidateResult
 
 // PredicateFn is the func declaration used to predicate node for task.
 type PredicateFn func(*TaskInfo, *NodeInfo) error
 
+// BestNodeFn is the func declaration used to return the nodeScores to plugins.
+type BestNodeFn func(*TaskInfo, map[float64][]*NodeInfo) *NodeInfo
+
 // EvictableFn is the func declaration used to evict tasks.
 type EvictableFn func(*TaskInfo, []*TaskInfo) []*TaskInfo
 

pkg/scheduler/conf/scheduler_conf.go

@@ -61,6 +61,8 @@ type PluginOption struct {
 	EnabledQueueOrder *bool `yaml:"enableQueueOrder"`
 	// EnabledPredicate defines whether predicateFn is enabled
 	EnabledPredicate *bool `yaml:"enablePredicate"`
+	// EnabledBestNode defines whether bestNodeFn is enabled
+	EnabledBestNode *bool `yaml:"enableBestNode"`
 	// EnabledNodeOrder defines whether NodeOrderFn is enabled
 	EnabledNodeOrder *bool `yaml:"enableNodeOrder"`
 	// Arguments defines the different arguments that can be given to different plugins

pkg/scheduler/framework/session.go

@@ -56,6 +56,7 @@ type Session struct {
 	taskOrderFns      map[string]api.CompareFn
 	namespaceOrderFns map[string]api.CompareFn
 	predicateFns      map[string]api.PredicateFn
+	bestNodeFns       map[string]api.BestNodeFn
 	nodeOrderFns      map[string]api.NodeOrderFn
 	batchNodeOrderFns map[string]api.BatchNodeOrderFn
 	nodeMapFns        map[string]api.NodeMapFn
@@ -86,6 +87,7 @@ func openSession(cache cache.Cache) *Session {
 		taskOrderFns:      map[string]api.CompareFn{},
 		namespaceOrderFns: map[string]api.CompareFn{},
 		predicateFns:      map[string]api.PredicateFn{},
+		bestNodeFns:       map[string]api.BestNodeFn{},
 		nodeOrderFns:      map[string]api.NodeOrderFn{},
 		batchNodeOrderFns: map[string]api.BatchNodeOrderFn{},
 		nodeMapFns:        map[string]api.NodeMapFn{},

pkg/scheduler/framework/session_plugins.go

@@ -67,6 +67,11 @@ func (ssn *Session) AddPredicateFn(name string, pf api.PredicateFn) {
 	ssn.predicateFns[name] = pf
 }
 
+// AddBestNodeFn add BestNode function
+func (ssn *Session) AddBestNodeFn(name string, pf api.BestNodeFn) {
+	ssn.bestNodeFns[name] = pf
+}
+
 // AddNodeOrderFn add Node order function
 func (ssn *Session) AddNodeOrderFn(name string, pf api.NodeOrderFn) {
 	ssn.nodeOrderFns[name] = pf
@@ -419,6 +424,26 @@ func (ssn *Session) PredicateFn(task *api.TaskInfo, node *api.NodeInfo) error {
 	return nil
 }
 
+// BestNodeFn invoke bestNode function of the plugins
+func (ssn *Session) BestNodeFn(task *api.TaskInfo, nodeScores map[float64][]*api.NodeInfo) *api.NodeInfo {
+	for _, tier := range ssn.Tiers {
+		for _, plugin := range tier.Plugins {
+			if !isEnabled(plugin.EnabledBestNode) {
+				continue
+			}
+			pfn, found := ssn.bestNodeFns[plugin.Name]
+			if !found {
+				continue
+			}
+			// Only the first plugin that enables and realizes bestNodeFn is allowed to choose best node for task
+			if bestNode := pfn(task, nodeScores); bestNode != nil {
+				return bestNode
+			}
+		}
+	}
+	return nil
+}
+
 // NodeOrderFn invoke node order function of the plugins
 func (ssn *Session) NodeOrderFn(task *api.TaskInfo, node *api.NodeInfo) (float64, error) {
 	priorityScore := 0.0