Treat replaced events that didn't change resourceVersion as resync events

Author: liggitt

staging/src/k8s.io/client-go/tools/cache/shared_informer.go

@@ -21,6 +21,7 @@ import (
 	"sync"
 	"time"
 
+	"k8s.io/apimachinery/pkg/api/meta"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/apimachinery/pkg/util/clock"
 	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
@@ -486,7 +487,21 @@ func (s *sharedIndexInformer) HandleDeltas(obj interface{}) error {
 				if err := s.indexer.Update(d.Object); err != nil {
 					return err
 				}
-				isSync := d.Type == Sync
+
+				isSync := false
+				switch {
+				case d.Type == Sync:
+					// Sync events are only propagated to listeners that requested resync
+					isSync = true
+				case d.Type == Replaced:
+					if accessor, err := meta.Accessor(d.Object); err == nil {
+						if oldAccessor, err := meta.Accessor(old); err == nil {
+							// Replaced events that didn't change resourceVersion are treated as resync events
+							// and only propagated to listeners that requested resync
+							isSync = accessor.GetResourceVersion() == oldAccessor.GetResourceVersion()
+						}
+					}
+				}
 				s.processor.distribute(updateNotification{oldObj: old, newObj: d.Object}, isSync)
 			} else {
 				if err := s.indexer.Add(d.Object); err != nil {

staging/src/k8s.io/client-go/tools/cache/shared_informer_test.go

@@ -271,8 +271,8 @@ func TestSharedInformerWatchDisruption(t *testing.T) {
 	// source simulates an apiserver object endpoint.
 	source := fcache.NewFakeControllerSource()
 
-	source.Add(&v1.Pod{ObjectMeta: metav1.ObjectMeta{Name: "pod1", UID: "pod1"}})
-	source.Add(&v1.Pod{ObjectMeta: metav1.ObjectMeta{Name: "pod2", UID: "pod2"}})
+	source.Add(&v1.Pod{ObjectMeta: metav1.ObjectMeta{Name: "pod1", UID: "pod1", ResourceVersion: "1"}})
+	source.Add(&v1.Pod{ObjectMeta: metav1.ObjectMeta{Name: "pod2", UID: "pod2", ResourceVersion: "2"}})
 
 	// create the shared informer and resync every 1s
 	informer := NewSharedInformer(source, &v1.Pod{}, 1*time.Second).(*sharedIndexInformer)
@@ -301,8 +301,8 @@ func TestSharedInformerWatchDisruption(t *testing.T) {
 	}
 
 	// Add pod3, bump pod2 but don't broadcast it, so that the change will be seen only on relist
-	source.AddDropWatch(&v1.Pod{ObjectMeta: metav1.ObjectMeta{Name: "pod3", UID: "pod3"}})
-	source.ModifyDropWatch(&v1.Pod{ObjectMeta: metav1.ObjectMeta{Name: "pod2", UID: "pod2"}})
+	source.AddDropWatch(&v1.Pod{ObjectMeta: metav1.ObjectMeta{Name: "pod3", UID: "pod3", ResourceVersion: "3"}})
+	source.ModifyDropWatch(&v1.Pod{ObjectMeta: metav1.ObjectMeta{Name: "pod2", UID: "pod2", ResourceVersion: "4"}})
 
 	// Ensure that nobody saw any changes
 	for _, listener := range listeners {
@@ -315,7 +315,7 @@ func TestSharedInformerWatchDisruption(t *testing.T) {
 		listener.receivedItemNames = []string{}
 	}
 
-	listenerNoResync.expectedItemNames = sets.NewString("pod1", "pod2", "pod3")
+	listenerNoResync.expectedItemNames = sets.NewString("pod2", "pod3")
 	listenerResync.expectedItemNames = sets.NewString("pod1", "pod2", "pod3")
 
 	// This calls shouldSync, which deletes noResync from the list of syncingListeners