Merge pull request kubernetes#127444 from dom4ha/fine-grained-qhints

Fine grain QueueHints for NodeAffinity plugin

Author: k8s-ci-robot

pkg/scheduler/framework/plugins/nodeaffinity/node_affinity.go

@@ -104,7 +104,7 @@ func (pl *NodeAffinity) EventsToRegister(_ context.Context) ([]framework.Cluster
 // isSchedulableAfterNodeChange is invoked whenever a node changed. It checks whether
 // that change made a previously unschedulable pod schedulable.
 func (pl *NodeAffinity) isSchedulableAfterNodeChange(logger klog.Logger, pod *v1.Pod, oldObj, newObj interface{}) (framework.QueueingHint, error) {
-	_, modifiedNode, err := util.As[*v1.Node](oldObj, newObj)
+	originalNode, modifiedNode, err := util.As[*v1.Node](oldObj, newObj)
 	if err != nil {
 		return framework.Queue, err
 	}
@@ -119,16 +119,27 @@ func (pl *NodeAffinity) isSchedulableAfterNodeChange(logger klog.Logger, pod *v1
 	if err != nil {
 		return framework.Queue, err
 	}
-	if isMatched {
-		logger.V(4).Info("node was created or updated, and matches with the pod's NodeAffinity", "pod", klog.KObj(pod), "node", klog.KObj(modifiedNode))
+	if !isMatched {
+		logger.V(5).Info("node was created or updated, but the pod's NodeAffinity doesn't match", "pod", klog.KObj(pod), "node", klog.KObj(modifiedNode))
+		return framework.QueueSkip, nil
+	}
+	// Since the node was added and it matches the pod's affinity criteria, we can unblock it.
+	if originalNode == nil {
+		logger.V(5).Info("node was created, and matches with the pod's NodeAffinity", "pod", klog.KObj(pod), "node", klog.KObj(modifiedNode))
 		return framework.Queue, nil
 	}
-
-	// TODO: also check if the original node meets the pod's requestments once preCheck is completely removed.
-	// See: https://github.com/kubernetes/kubernetes/issues/110175
-
-	logger.V(4).Info("node was created or updated, but it doesn't make this pod schedulable", "pod", klog.KObj(pod), "node", klog.KObj(modifiedNode))
-	return framework.QueueSkip, nil
+	// At this point we know the operation is update so we can narrow down the criteria to unmatch -> match changes only
+	// (necessary affinity label was added to the node in this case).
+	wasMatched, err := requiredNodeAffinity.Match(originalNode)
+	if err != nil {
+		return framework.Queue, err
+	}
+	if wasMatched {
+		logger.V(5).Info("node updated, but the pod's NodeAffinity hasn't changed", "pod", klog.KObj(pod), "node", klog.KObj(modifiedNode))
+		return framework.QueueSkip, nil
+	}
+	logger.V(5).Info("node was updated and the pod's NodeAffinity changed to matched", "pod", klog.KObj(pod), "node", klog.KObj(modifiedNode))
+	return framework.Queue, nil
 }
 
 // PreFilter builds and writes cycle state used by Filter.

pkg/scheduler/framework/plugins/nodeaffinity/node_affinity_test.go

@@ -1297,6 +1297,13 @@ func Test_isSchedulableAfterNodeChange(t *testing.T) {
 			newObj:       st.MakeNode().Label("foo", "bar").Obj(),
 			expectedHint: framework.Queue,
 		},
+		"skip-unrelated-change-that-keeps-pod-schedulable": {
+			args:         &config.NodeAffinityArgs{},
+			pod:          podWithNodeAffinity.Obj(),
+			oldObj:       st.MakeNode().Label("foo", "bar").Obj(),
+			newObj:       st.MakeNode().Capacity(nil).Label("foo", "bar").Obj(),
+			expectedHint: framework.QueueSkip,
+		},
 		"skip-queue-on-add-scheduler-enforced-node-affinity": {
 			args: &config.NodeAffinityArgs{
 				AddedAffinity: &v1.NodeAffinity{

pkg/scheduler/framework/types.go

@@ -146,7 +146,7 @@ const (
 
 type ClusterEventWithHint struct {
 	Event ClusterEvent
-	// QueueingHintFn is executed for the plugin rejected by this plugin when the above Event happens,
+	// QueueingHintFn is executed for the Pod rejected by this plugin when the above Event happens,
 	// and filters out events to reduce useless retry of Pod's scheduling.
 	// It's an optional field. If not set,
 	// the scheduling of Pods will be always retried with backoff when this Event happens.

test/integration/scheduler/queue_test.go

@@ -271,7 +271,48 @@ func TestCoreResourceEnqueue(t *testing.T) {
 				// It causes pod1 to be requeued.
 				// It causes pod2 not to be requeued.
 				if _, err := testCtx.ClientSet.CoreV1().Nodes().Update(testCtx.Ctx, st.MakeNode().Name("fake-node1").Label("group", "b").Obj(), metav1.UpdateOptions{}); err != nil {
-					return fmt.Errorf("failed to remove taints off the node: %w", err)
+					return fmt.Errorf("failed to update the pod: %w", err)
+				}
+				return nil
+			},
+			wantRequeuedPods: sets.New("pod1"),
+		},
+		{
+			name: "Pod rejected by the NodeAffinity plugin is not requeued when an updated Node haven't changed the 'match' verdict",
+			initialNodes: []*v1.Node{
+				st.MakeNode().Name("node1").Label("group", "a").Capacity(map[v1.ResourceName]string{v1.ResourceCPU: "2"}).Obj(),
+				st.MakeNode().Name("node2").Label("group", "b").Obj()},
+			pods: []*v1.Pod{
+				// - The initial pod would be accepted by the NodeAffinity plugin for node1, but will be blocked by the NodeResources plugin.
+				// - The pod will be blocked by the NodeAffinity plugin for node2, therefore we know NodeAffinity will be queried for qhint for both testing nodes.
+				st.MakePod().Name("pod1").NodeAffinityIn("group", []string{"a"}, st.NodeSelectorTypeMatchExpressions).Req(map[v1.ResourceName]string{v1.ResourceCPU: "4"}).Container("image").Obj(),
+			},
+			triggerFn: func(testCtx *testutils.TestContext) error {
+				// Trigger a NodeUpdate event to add new label.
+				// It won't cause pod to be requeued, because there was a match already before the update, meaning this plugin wasn't blocking the scheduling.
+				if _, err := testCtx.ClientSet.CoreV1().Nodes().Update(testCtx.Ctx, st.MakeNode().Name("node1").Label("group", "a").Label("node", "fake-node").Obj(), metav1.UpdateOptions{}); err != nil {
+					return fmt.Errorf("failed to update the pod: %w", err)
+				}
+				return nil
+			},
+			wantRequeuedPods:          sets.Set[string]{},
+			enableSchedulingQueueHint: []bool{true},
+		},
+		{
+			name:         "Pod rejected by the NodeAffinity plugin is requeued when a Node is added",
+			initialNodes: []*v1.Node{st.MakeNode().Name("fake-node1").Label("group", "a").Obj()},
+			pods: []*v1.Pod{
+				// - Pod1 will be rejected by the NodeAffinity plugin.
+				st.MakePod().Name("pod1").NodeAffinityIn("group", []string{"b"}, st.NodeSelectorTypeMatchExpressions).Container("image").Obj(),
+				// - Pod2 will be rejected by the NodeAffinity plugin.
+				st.MakePod().Name("pod2").NodeAffinityIn("group", []string{"c"}, st.NodeSelectorTypeMatchExpressions).Container("image").Obj(),
+			},
+			triggerFn: func(testCtx *testutils.TestContext) error {
+				// Trigger a NodeAdd event with the awaited label.
+				// It causes pod1 to be requeued.
+				// It causes pod2 not to be requeued.
+				if _, err := testCtx.ClientSet.CoreV1().Nodes().Create(testCtx.Ctx, st.MakeNode().Name("fake-node2").Label("group", "b").Obj(), metav1.CreateOptions{}); err != nil {
+					return fmt.Errorf("failed to update the pod: %w", err)
 				}
 				return nil
 			},