Merge pull request kubernetes#92391 from adtac/adtac/reserve-failure

scheduler: run Unreserve if Reserve fails

Author: k8s-ci-robot

pkg/scheduler/framework/runtime/framework.go

@@ -788,7 +788,8 @@ func (f *frameworkImpl) runPostBindPlugin(ctx context.Context, pl framework.Post
 // RunReservePluginsReserve runs the Reserve method in the set of configured
 // reserve plugins. If any of these plugins returns an error, it does not
 // continue running the remaining ones and returns the error. In such a case,
-// the pod will not be scheduled.
+// the pod will not be scheduled and the caller will be expected to call
+// RunReservePluginsUnreserve.
 func (f *frameworkImpl) RunReservePluginsReserve(ctx context.Context, state *framework.CycleState, pod *v1.Pod, nodeName string) (status *framework.Status) {
 	startTime := time.Now()
 	defer func() {

pkg/scheduler/framework/v1alpha1/interface.go

@@ -333,11 +333,14 @@ type ScorePlugin interface {
 type ReservePlugin interface {
 	Plugin
 	// Reserve is called by the scheduling framework when the scheduler cache is
-	// updated.
+	// updated. If this method returns a failed Status, the scheduler will call
+	// the Unreserve method for all enabled ReservePlugins.
 	Reserve(ctx context.Context, state *CycleState, p *v1.Pod, nodeName string) *Status
 	// Unreserve is called by the scheduling framework when a reserved pod was
 	// rejected, an error occurred during reservation of subsequent plugins, or
-	// in a later phase. The Unreserve method implementation must be idempotent.
+	// in a later phase. The Unreserve method implementation must be idempotent
+	// and may be called by the scheduler even if the corresponding Reserve
+	// method for the same plugin was not called.
 	Unreserve(ctx context.Context, state *CycleState, p *v1.Pod, nodeName string)
 }
 

pkg/scheduler/scheduler.go

@@ -520,6 +520,8 @@ func (sched *Scheduler) scheduleOne(ctx context.Context) {
 	if sts := prof.RunReservePluginsReserve(schedulingCycleCtx, state, assumedPod, scheduleResult.SuggestedHost); !sts.IsSuccess() {
 		sched.recordSchedulingFailure(prof, assumedPodInfo, sts.AsError(), SchedulerError, "")
 		metrics.PodScheduleError(prof.Name, metrics.SinceInSeconds(start))
+		// trigger un-reserve to clean up state associated with the reserved Pod
+		prof.RunReservePluginsUnreserve(schedulingCycleCtx, state, assumedPod, scheduleResult.SuggestedHost)
 		return
 	}
 

test/integration/scheduler/framework_test.go

@@ -269,6 +269,7 @@ func (rp *ReservePlugin) Unreserve(ctx context.Context, state *framework.CycleSt
 func (rp *ReservePlugin) reset() {
 	rp.numReserveCalled = 0
 	rp.numUnreserveCalled = 0
+	rp.failReserve = false
 }
 
 // Name returns name of the plugin.
@@ -1006,30 +1007,39 @@ func TestReservePluginUnreserve(t *testing.T) {
 	defer testutils.CleanupTest(t, testCtx)
 
 	tests := []struct {
-		name        string
-		preBindFail bool
+		name             string
+		failReserve      bool
+		failReserveIndex int
+		failPreBind      bool
 	}{
+		{
+			name:             "fail reserve",
+			failReserve:      true,
+			failReserveIndex: 1,
+		},
 		{
 			name:        "fail preBind",
-			preBindFail: true,
+			failPreBind: true,
 		},
 		{
-			name:        "pass preBind",
-			preBindFail: false,
+			name: "pass everything",
 		},
 	}
 
 	for _, test := range tests {
 		t.Run(test.name, func(t *testing.T) {
-			preBindPlugin.failPreBind = test.preBindFail
+			preBindPlugin.failPreBind = test.failPreBind
+			if test.failReserve {
+				reservePlugins[test.failReserveIndex].failReserve = true
+			}
 			// Create a best effort pod.
 			pod, err := createPausePod(testCtx.ClientSet,
 				initPausePod(&pausePodConfig{Name: "test-pod", Namespace: testCtx.NS.Name}))
 			if err != nil {
 				t.Errorf("Error while creating a test pod: %v", err)
 			}
 
-			if test.preBindFail {
+			if test.failPreBind || test.failReserve {
 				if err = wait.Poll(10*time.Millisecond, 30*time.Second, podSchedulingError(testCtx.ClientSet, pod.Namespace, pod.Name)); err != nil {
 					t.Errorf("Expected a scheduling error, but didn't get it: %v", err)
 				}