Merge pull request #22579 from bprashanth/graceful_rc

pkg/controller/controller_utils.go

@@ -35,6 +35,7 @@ import (
 	"k8s.io/kubernetes/pkg/runtime"
 	"k8s.io/kubernetes/pkg/util"
 	"k8s.io/kubernetes/pkg/util/integer"
+	"k8s.io/kubernetes/pkg/util/sets"
 )
 
 const (
@@ -243,11 +244,105 @@ func (e *ControlleeExpectations) GetExpectations() (int64, int64) {
 	return atomic.LoadInt64(&e.add), atomic.LoadInt64(&e.del)
 }
 
-// NewControllerExpectations returns a store for ControlleeExpectations.
+// NewControllerExpectations returns a store for ControllerExpectations.
 func NewControllerExpectations() *ControllerExpectations {
 	return &ControllerExpectations{cache.NewStore(ExpKeyFunc)}
 }
 
+// UIDSetKeyFunc to parse out the key from a UIDSet.
+var UIDSetKeyFunc = func(obj interface{}) (string, error) {
+	if u, ok := obj.(*UIDSet); ok {
+		return u.key, nil
+	}
+	return "", fmt.Errorf("Could not find key for obj %#v", obj)
+}
+
+// UIDSet holds a key and a set of UIDs. Used by the
+// UIDTrackingControllerExpectations to remember which UID it has seen/still
+// waiting for.
+type UIDSet struct {
+	sets.String
+	key string
+}
+
+// UIDTrackingControllerExpectations tracks the UID of the pods it deletes.
+// This cache is needed over plain old expectations to safely handle graceful
+// deletion. The desired behavior is to treat an update that sets the
+// DeletionTimestamp on an object as a delete. To do so consistenly, one needs
+// to remember the expected deletes so they aren't double counted.
+// TODO: Track creates as well (#22599)
+type UIDTrackingControllerExpectations struct {
+	ControllerExpectationsInterface
+	// TODO: There is a much nicer way to do this that involves a single store,
+	// a lock per entry, and a ControlleeExpectationsInterface type.
+	uidStoreLock sync.Mutex
+	// Store used for the UIDs associated with any expectation tracked via the
+	// ControllerExpectationsInterface.
+	uidStore cache.Store
+}
+
+// GetUIDs is a convenience method to avoid exposing the set of expected uids.
+// The returned set is not thread safe, all modifications must be made holding
+// the uidStoreLock.
+func (u *UIDTrackingControllerExpectations) GetUIDs(controllerKey string) sets.String {
+	if uid, exists, err := u.uidStore.GetByKey(controllerKey); err == nil && exists {
+		return uid.(*UIDSet).String
+	}
+	return nil
+}
+
+// ExpectDeletions records expectations for the given deleteKeys, against the given controller.
+func (u *UIDTrackingControllerExpectations) ExpectDeletions(rcKey string, deletedKeys []string) error {
+	u.uidStoreLock.Lock()
+	defer u.uidStoreLock.Unlock()
+
+	if existing := u.GetUIDs(rcKey); existing != nil && existing.Len() != 0 {
+		glog.Errorf("Clobbering existing delete keys: %+v", existing)
+	}
+	expectedUIDs := sets.NewString()
+	for _, k := range deletedKeys {
+		expectedUIDs.Insert(k)
+	}
+	glog.V(4).Infof("Controller %v waiting on deletions for: %+v", rcKey, deletedKeys)
+	if err := u.uidStore.Add(&UIDSet{expectedUIDs, rcKey}); err != nil {
+		return err
+	}
+	return u.ControllerExpectationsInterface.ExpectDeletions(rcKey, expectedUIDs.Len())
+}
+
+// DeletionObserved records the given deleteKey as a deletion, for the given rc.
+func (u *UIDTrackingControllerExpectations) DeletionObserved(rcKey, deleteKey string) {
+	u.uidStoreLock.Lock()
+	defer u.uidStoreLock.Unlock()
+
+	uids := u.GetUIDs(rcKey)
+	if uids != nil && uids.Has(deleteKey) {
+		glog.V(4).Infof("Controller %v received delete for pod %v", rcKey, deleteKey)
+		u.ControllerExpectationsInterface.DeletionObserved(rcKey)
+		uids.Delete(deleteKey)
+	}
+}
+
+// DeleteExpectations deletes the UID set and invokes DeleteExpectations on the
+// underlying ControllerExpectationsInterface.
+func (u *UIDTrackingControllerExpectations) DeleteExpectations(rcKey string) {
+	u.uidStoreLock.Lock()
+	defer u.uidStoreLock.Unlock()
+
+	u.ControllerExpectationsInterface.DeleteExpectations(rcKey)
+	if uidExp, exists, err := u.uidStore.GetByKey(rcKey); err == nil && exists {
+		if err := u.uidStore.Delete(uidExp); err != nil {
+			glog.V(2).Infof("Error deleting uid expectations for controller %v: %v", rcKey, err)
+		}
+	}
+}
+
+// NewUIDTrackingControllerExpectations returns a wrapper around
+// ControllerExpectations that is aware of deleteKeys.
+func NewUIDTrackingControllerExpectations(ce ControllerExpectationsInterface) *UIDTrackingControllerExpectations {
+	return &UIDTrackingControllerExpectations{ControllerExpectationsInterface: ce, uidStore: cache.NewStore(UIDSetKeyFunc)}
+}
+
 // PodControlInterface is an interface that knows how to add or delete pods
 // created as an interface to allow testing.
 type PodControlInterface interface {
@@ -517,6 +612,14 @@ func FilterActiveReplicaSets(replicaSets []*extensions.ReplicaSet) []*extensions
 	return active
 }
 
+// PodKey returns a key unique to the given pod within a cluster.
+// It's used so we consistently use the same key scheme in this module.
+// It does exactly what cache.MetaNamespaceKeyFunc would have done
+// expcept there's not possibility for error since we know the exact type.
+func PodKey(pod *api.Pod) string {
+	return fmt.Sprintf("%v/%v", pod.Namespace, pod.Name)
+}
+
 // ControllersByCreationTimestamp sorts a list of ReplicationControllers by creation timestamp, using their names as a tie breaker.
 type ControllersByCreationTimestamp []*api.ReplicationController
 

pkg/controller/controller_utils_test.go

@@ -183,6 +183,57 @@ func TestControllerExpectations(t *testing.T) {
 	}
 }
 
+func TestUIDExpectations(t *testing.T) {
+	uidExp := NewUIDTrackingControllerExpectations(NewControllerExpectations())
+	rcList := []*api.ReplicationController{
+		newReplicationController(2),
+		newReplicationController(1),
+		newReplicationController(0),
+		newReplicationController(5),
+	}
+	rcToPods := map[string][]string{}
+	rcKeys := []string{}
+	for i := range rcList {
+		rc := rcList[i]
+		rcName := fmt.Sprintf("rc-%v", i)
+		rc.Name = rcName
+		rc.Spec.Selector[rcName] = rcName
+		podList := newPodList(nil, 5, api.PodRunning, rc)
+		rcKey, err := KeyFunc(rc)
+		if err != nil {
+			t.Fatalf("Couldn't get key for object %+v: %v", rc, err)
+		}
+		rcKeys = append(rcKeys, rcKey)
+		rcPodNames := []string{}
+		for i := range podList.Items {
+			p := &podList.Items[i]
+			p.Name = fmt.Sprintf("%v-%v", p.Name, rc.Name)
+			rcPodNames = append(rcPodNames, PodKey(p))
+		}
+		rcToPods[rcKey] = rcPodNames
+		uidExp.ExpectDeletions(rcKey, rcPodNames)
+	}
+	for i := range rcKeys {
+		j := rand.Intn(i + 1)
+		rcKeys[i], rcKeys[j] = rcKeys[j], rcKeys[i]
+	}
+	for _, rcKey := range rcKeys {
+		if uidExp.SatisfiedExpectations(rcKey) {
+			t.Errorf("Controller %v satisfied expectations before deletion", rcKey)
+		}
+		for _, p := range rcToPods[rcKey] {
+			uidExp.DeletionObserved(rcKey, p)
+		}
+		if !uidExp.SatisfiedExpectations(rcKey) {
+			t.Errorf("Controller %v didn't satisfy expectations after deletion", rcKey)
+		}
+		uidExp.DeleteExpectations(rcKey)
+		if uidExp.GetUIDs(rcKey) != nil {
+			t.Errorf("Failed to delete uid expectations for %v", rcKey)
+		}
+	}
+}
+
 func TestCreatePods(t *testing.T) {
 	ns := api.NamespaceDefault
 	body := runtime.EncodeOrDie(testapi.Default.Codec(), &api.Pod{ObjectMeta: api.ObjectMeta{Name: "empty_pod"}})

pkg/controller/replicaset/replica_set.go

@@ -49,7 +49,7 @@ const (
 	// happens based on contents in local pod storage.
 	FullControllerResyncPeriod = 30 * time.Second
 
-	// Realistic value of the burstReplica field for the replication manager based off
+	// Realistic value of the burstReplica field for the replica set manager based off
 	// performance requirements for kubernetes 1.0.
 	BurstReplicas = 500
 
@@ -73,8 +73,8 @@ type ReplicaSetController struct {
 	// To allow injection of syncReplicaSet for testing.
 	syncHandler func(rsKey string) error
 
-	// A TTLCache of pod creates/deletes each ReplicaSet expects to see
-	expectations controller.ControllerExpectationsInterface
+	// A TTLCache of pod creates/deletes each rc expects to see.
+	expectations *controller.UIDTrackingControllerExpectations
 
 	// A store of ReplicaSets, populated by the rsController
 	rsStore cache.StoreToReplicaSetLister
@@ -107,7 +107,7 @@ func NewReplicaSetController(kubeClient clientset.Interface, resyncPeriod contro
 			Recorder:   eventBroadcaster.NewRecorder(api.EventSource{Component: "replicaset-controller"}),
 		},
 		burstReplicas: burstReplicas,
-		expectations:  controller.NewControllerExpectations(),
+		expectations:  controller.NewUIDTrackingControllerExpectations(controller.NewControllerExpectations()),
 		queue:         workqueue.New(),
 	}
 
@@ -297,17 +297,16 @@ func (rsc *ReplicaSetController) addPod(obj interface{}) {
 	}
 	rsKey, err := controller.KeyFunc(rs)
 	if err != nil {
-		glog.Errorf("Couldn't get key for replication controller %#v: %v", rs, err)
+		glog.Errorf("Couldn't get key for replica set %#v: %v", rs, err)
 		return
 	}
 	if pod.DeletionTimestamp != nil {
 		// on a restart of the controller manager, it's possible a new pod shows up in a state that
 		// is already pending deletion. Prevent the pod from being a creation observation.
-		glog.V(4).Infof("Add for pod %v with deletion timestamp %+v, counted as new deletion for rs %v", pod.Name, pod.DeletionTimestamp, rsKey)
-		rsc.expectations.DeletionObserved(rsKey)
-	} else {
-		rsc.expectations.CreationObserved(rsKey)
+		rsc.deletePod(pod)
+		return
 	}
+	rsc.expectations.CreationObserved(rsKey)
 	rsc.enqueueReplicaSet(rs)
 }
 
@@ -326,22 +325,15 @@ func (rsc *ReplicaSetController) updatePod(old, cur interface{}) {
 	if rs == nil {
 		return
 	}
-	rsKey, err := controller.KeyFunc(rs)
-	if err != nil {
-		glog.Errorf("Couldn't get key for replication controller %#v: %v", rs, err)
-		return
-	}
 
-	if curPod.DeletionTimestamp != nil && oldPod.DeletionTimestamp == nil {
+	if curPod.DeletionTimestamp != nil {
 		// when a pod is deleted gracefully it's deletion timestamp is first modified to reflect a grace period,
 		// and after such time has passed, the kubelet actually deletes it from the store. We receive an update
 		// for modification of the deletion timestamp and expect an rs to create more replicas asap, not wait
 		// until the kubelet actually deletes the pod. This is different from the Phase of a pod changing, because
 		// an rs never initiates a phase change, and so is never asleep waiting for the same.
-		glog.V(4).Infof("Update to pod %v with deletion timestamp %+v counted as delete for rs %v", curPod.Name, curPod.DeletionTimestamp, rsKey)
-		rsc.expectations.DeletionObserved(rsKey)
-	} else {
-		glog.V(4).Infof("Update to pod %v with deletion timestamp %+v. Not counting it as a new deletion for rs %v", curPod.Name, curPod.DeletionTimestamp, rsKey)
+		rsc.deletePod(curPod)
+		return
 	}
 
 	rsc.enqueueReplicaSet(rs)
@@ -375,21 +367,14 @@ func (rsc *ReplicaSetController) deletePod(obj interface{}) {
 			return
 		}
 	}
-	glog.V(4).Infof("Pod %s deleted: %+v.", pod.Name, pod)
+	glog.V(4).Infof("Pod %s/%s deleted through %v, timestamp %+v: %+v.", pod.Namespace, pod.Name, utilruntime.GetCaller(), pod.DeletionTimestamp, pod)
 	if rs := rsc.getPodReplicaSet(pod); rs != nil {
 		rsKey, err := controller.KeyFunc(rs)
 		if err != nil {
 			glog.Errorf("Couldn't get key for ReplicaSet %#v: %v", rs, err)
 			return
 		}
-		// This method only manages expectations for the case where a pod is
-		// deleted without a grace period.
-		if pod.DeletionTimestamp == nil {
-			glog.V(4).Infof("Received new delete for rs %v, pod %v", rsKey, pod.Name)
-			rsc.expectations.DeletionObserved(rsKey)
-		} else {
-			glog.V(4).Infof("Received delete for rs %v pod %v with non nil deletion timestamp %+v. Not counting it as a new deletion.", rsKey, pod.Name, pod.DeletionTimestamp)
-		}
+		rsc.expectations.DeletionObserved(rsKey, controller.PodKey(pod))
 		rsc.enqueueReplicaSet(rs)
 	}
 }
@@ -442,6 +427,11 @@ func (rsc *ReplicaSetController) manageReplicas(filteredPods []*api.Pod, rs *ext
 		if diff > rsc.burstReplicas {
 			diff = rsc.burstReplicas
 		}
+		// TODO: Track UIDs of creates just like deletes. The problem currently
+		// is we'd need to wait on the result of a create to record the pod's
+		// UID, which would require locking *across* the create, which will turn
+		// into a performance bottleneck. We should generate a UID for the pod
+		// beforehand and store it via ExpectCreations.
 		rsc.expectations.ExpectCreations(rsKey, diff)
 		wait := sync.WaitGroup{}
 		wait.Add(diff)
@@ -462,7 +452,6 @@ func (rsc *ReplicaSetController) manageReplicas(filteredPods []*api.Pod, rs *ext
 		if diff > rsc.burstReplicas {
 			diff = rsc.burstReplicas
 		}
-		rsc.expectations.ExpectDeletions(rsKey, diff)
 		glog.V(2).Infof("Too many %q/%q replicas, need %d, deleting %d", rs.Namespace, rs.Name, rs.Spec.Replicas, diff)
 		// No need to sort pods if we are about to delete all of them
 		if rs.Spec.Replicas != 0 {
@@ -471,7 +460,17 @@ func (rsc *ReplicaSetController) manageReplicas(filteredPods []*api.Pod, rs *ext
 			// in the earlier stages whenever possible.
 			sort.Sort(controller.ActivePods(filteredPods))
 		}
-
+		// Snapshot the UIDs (ns/name) of the pods we're expecting to see
+		// deleted, so we know to record their expectations exactly once either
+		// when we see it as an update of the deletion timestamp, or as a delete.
+		// Note that if the labels on a pod/rs change in a way that the pod gets
+		// orphaned, the rs will only wake up after the expectations have
+		// expired even if other pods are deleted.
+		deletedPodKeys := []string{}
+		for i := 0; i < diff; i++ {
+			deletedPodKeys = append(deletedPodKeys, controller.PodKey(filteredPods[i]))
+		}
+		rsc.expectations.ExpectDeletions(rsKey, deletedPodKeys)
 		wait := sync.WaitGroup{}
 		wait.Add(diff)
 		for i := 0; i < diff; i++ {
@@ -479,8 +478,9 @@ func (rsc *ReplicaSetController) manageReplicas(filteredPods []*api.Pod, rs *ext
 				defer wait.Done()
 				if err := rsc.podControl.DeletePod(rs.Namespace, filteredPods[ix].Name, rs); err != nil {
 					// Decrement the expected number of deletes because the informer won't observe this deletion
-					glog.V(2).Infof("Failed deletion, decrementing expectations for replica set %q/%q", rs.Namespace, rs.Name)
-					rsc.expectations.DeletionObserved(rsKey)
+					podKey := controller.PodKey(filteredPods[ix])
+					glog.V(2).Infof("Failed to delete %v, decrementing expectations for controller %q/%q", podKey, rs.Namespace, rs.Name)
+					rsc.expectations.DeletionObserved(rsKey, podKey)
 					utilruntime.HandleError(err)
 				}
 			}(i)

pkg/controller/replicaset/replica_set_test.go

@@ -22,6 +22,7 @@ import (
 	"fmt"
 	"math/rand"
 	"net/http/httptest"
+	"strings"
 	"testing"
 	"time"
 
@@ -652,6 +653,7 @@ func TestControllerUpdateStatusWithFailure(t *testing.T) {
 	}
 }
 
+// TODO: This test is too hairy for a unittest. It should be moved to an E2E suite.
 func doTestControllerBurstReplicas(t *testing.T, burstReplicas, numReplicas int) {
 	client := clientset.NewForConfigOrDie(&restclient.Config{Host: "", ContentConfig: restclient.ContentConfig{GroupVersion: testapi.Default.GroupVersion()}})
 	fakePodControl := controller.FakePodControl{}
@@ -703,7 +705,7 @@ func doTestControllerBurstReplicas(t *testing.T, burstReplicas, numReplicas int)
 
 				podExp, exists, err := manager.expectations.GetExpectations(rsKey)
 				if !exists || err != nil {
-					t.Fatalf("Did not find expectations for ReplicaSet.")
+					t.Fatalf("Did not find expectations for rc.")
 				}
 				if add, _ := podExp.GetExpectations(); add != 1 {
 					t.Fatalf("Expectations are wrong %v", podExp)
@@ -714,9 +716,27 @@ func doTestControllerBurstReplicas(t *testing.T, burstReplicas, numReplicas int)
 					expectedPods = burstReplicas
 				}
 				validateSyncReplicaSet(t, &fakePodControl, 0, expectedPods)
-				for i := 0; i < expectedPods-1; i++ {
-					manager.podStore.Store.Delete(&pods.Items[i])
-					manager.deletePod(&pods.Items[i])
+
+				// To accurately simulate a watch we must delete the exact pods
+				// the rs is waiting for.
+				expectedDels := manager.expectations.GetUIDs(getKey(rsSpec, t))
+				podsToDelete := []*api.Pod{}
+				for _, key := range expectedDels.List() {
+					nsName := strings.Split(key, "/")
+					podsToDelete = append(podsToDelete, &api.Pod{
+						ObjectMeta: api.ObjectMeta{
+							Name:      nsName[1],
+							Namespace: nsName[0],
+							Labels:    rsSpec.Spec.Selector.MatchLabels,
+						},
+					})
+				}
+				// Don't delete all pods because we confirm that the last pod
+				// has exactly one expectation at the end, to verify that we
+				// don't double delete.
+				for i := range podsToDelete[1:] {
+					manager.podStore.Delete(podsToDelete[i])
+					manager.deletePod(podsToDelete[i])
 				}
 				podExp, exists, err := manager.expectations.GetExpectations(rsKey)
 				if !exists || err != nil {
@@ -739,8 +759,20 @@ func doTestControllerBurstReplicas(t *testing.T, burstReplicas, numReplicas int)
 				manager.podStore.Store.Add(&pods.Items[expectedPods-1])
 				manager.addPod(&pods.Items[expectedPods-1])
 			} else {
-				manager.podStore.Store.Delete(&pods.Items[expectedPods-1])
-				manager.deletePod(&pods.Items[expectedPods-1])
+				expectedDel := manager.expectations.GetUIDs(getKey(rsSpec, t))
+				if expectedDel.Len() != 1 {
+					t.Fatalf("Waiting on unexpected number of deletes.")
+				}
+				nsName := strings.Split(expectedDel.List()[0], "/")
+				lastPod := &api.Pod{
+					ObjectMeta: api.ObjectMeta{
+						Name:      nsName[1],
+						Namespace: nsName[0],
+						Labels:    rsSpec.Spec.Selector.MatchLabels,
+					},
+				}
+				manager.podStore.Store.Delete(lastPod)
+				manager.deletePod(lastPod)
 			}
 			pods.Items = pods.Items[expectedPods:]
 		}
@@ -788,14 +820,14 @@ func TestRSSyncExpectations(t *testing.T) {
 	manager.podStore.Store.Add(&pods.Items[0])
 	postExpectationsPod := pods.Items[1]
 
-	manager.expectations = FakeRSExpectations{
+	manager.expectations = controller.NewUIDTrackingControllerExpectations(FakeRSExpectations{
 		controller.NewControllerExpectations(), true, func() {
 			// If we check active pods before checking expectataions, the
 			// ReplicaSet will create a new replica because it doesn't see
 			// this pod, but has fulfilled its expectations.
 			manager.podStore.Store.Add(&postExpectationsPod)
 		},
-	}
+	})
 	manager.syncReplicaSet(getKey(rsSpec, t))
 	validateSyncReplicaSet(t, &fakePodControl, 0, 0)
 }
@@ -925,7 +957,7 @@ func TestDeletionTimestamp(t *testing.T) {
 	}
 	pod := newPodList(nil, 1, api.PodPending, labelMap, rs).Items[0]
 	pod.DeletionTimestamp = &unversioned.Time{time.Now()}
-	manager.expectations.SetExpectations(rsKey, 0, 1)
+	manager.expectations.ExpectDeletions(rsKey, []string{controller.PodKey(&pod)})
 
 	// A pod added with a deletion timestamp should decrement deletions, not creations.
 	manager.addPod(&pod)
@@ -944,7 +976,7 @@ func TestDeletionTimestamp(t *testing.T) {
 	// An update from no deletion timestamp to having one should be treated
 	// as a deletion.
 	oldPod := newPodList(nil, 1, api.PodPending, labelMap, rs).Items[0]
-	manager.expectations.SetExpectations(rsKey, 0, 1)
+	manager.expectations.ExpectDeletions(rsKey, []string{controller.PodKey(&pod)})
 	manager.updatePod(&oldPod, &pod)
 
 	queueRC, _ = manager.queue.Get()
@@ -960,7 +992,14 @@ func TestDeletionTimestamp(t *testing.T) {
 
 	// An update to the pod (including an update to the deletion timestamp)
 	// should not be counted as a second delete.
-	manager.expectations.SetExpectations(rsKey, 0, 1)
+	secondPod := &api.Pod{
+		ObjectMeta: api.ObjectMeta{
+			Namespace: pod.Namespace,
+			Name:      "secondPod",
+			Labels:    pod.Labels,
+		},
+	}
+	manager.expectations.ExpectDeletions(rsKey, []string{controller.PodKey(secondPod)})
 	oldPod.DeletionTimestamp = &unversioned.Time{time.Now()}
 	manager.updatePod(&oldPod, &pod)
 
@@ -977,9 +1016,8 @@ func TestDeletionTimestamp(t *testing.T) {
 		t.Fatalf("Wrong expectations %+v", podExp)
 	}
 
-	// A pod with a nil timestamp should be counted as a deletion.
-	pod.DeletionTimestamp = nil
-	manager.deletePod(&pod)
+	// Deleting the second pod should clear expectations.
+	manager.deletePod(secondPod)
 
 	queueRC, _ = manager.queue.Get()
 	if queueRC != rsKey {

pkg/controller/replication/replication_controller.go

@@ -72,8 +72,8 @@ type ReplicationManager struct {
 	// To allow injection of syncReplicationController for testing.
 	syncHandler func(rcKey string) error
 
-	// A TTLCache of pod creates/deletes each rc expects to see
-	expectations controller.ControllerExpectationsInterface
+	// A TTLCache of pod creates/deletes each rc expects to see.
+	expectations *controller.UIDTrackingControllerExpectations
 
 	// A store of replication controllers, populated by the rcController
 	rcStore cache.StoreToReplicationControllerLister
@@ -106,7 +106,7 @@ func NewReplicationManager(kubeClient clientset.Interface, resyncPeriod controll
 			Recorder:   eventBroadcaster.NewRecorder(api.EventSource{Component: "replication-controller"}),
 		},
 		burstReplicas: burstReplicas,
-		expectations:  controller.NewControllerExpectations(),
+		expectations:  controller.NewUIDTrackingControllerExpectations(controller.NewControllerExpectations()),
 		queue:         workqueue.New(),
 	}
 
@@ -300,11 +300,10 @@ func (rm *ReplicationManager) addPod(obj interface{}) {
 	if pod.DeletionTimestamp != nil {
 		// on a restart of the controller manager, it's possible a new pod shows up in a state that
 		// is already pending deletion. Prevent the pod from being a creation observation.
-		glog.V(4).Infof("Add for pod %v with deletion timestamp %+v, counted as new deletion for rc %v", pod.Name, pod.DeletionTimestamp, rcKey)
-		rm.expectations.DeletionObserved(rcKey)
-	} else {
-		rm.expectations.CreationObserved(rcKey)
+		rm.deletePod(pod)
+		return
 	}
+	rm.expectations.CreationObserved(rcKey)
 	rm.enqueueController(rc)
 }
 
@@ -321,25 +320,17 @@ func (rm *ReplicationManager) updatePod(old, cur interface{}) {
 	if rc == nil {
 		return
 	}
-	rcKey, err := controller.KeyFunc(rc)
-	if err != nil {
-		glog.Errorf("Couldn't get key for replication controller %#v: %v", rc, err)
-		return
-	}
 	oldPod := old.(*api.Pod)
 
-	if curPod.DeletionTimestamp != nil && oldPod.DeletionTimestamp == nil {
+	if curPod.DeletionTimestamp != nil {
 		// when a pod is deleted gracefully it's deletion timestamp is first modified to reflect a grace period,
 		// and after such time has passed, the kubelet actually deletes it from the store. We receive an update
 		// for modification of the deletion timestamp and expect an rc to create more replicas asap, not wait
 		// until the kubelet actually deletes the pod. This is different from the Phase of a pod changing, because
 		// an rc never initiates a phase change, and so is never asleep waiting for the same.
-		glog.V(4).Infof("Update to pod %v with deletion timestamp %+v counted as delete for rc %v", curPod.Name, curPod.DeletionTimestamp, rcKey)
-		rm.expectations.DeletionObserved(rcKey)
-	} else {
-		glog.V(4).Infof("Update to pod %v with deletion timestamp %+v. Not counting it as a new deletion for rc %v.", curPod.Name, curPod.DeletionTimestamp, rcKey)
+		rm.deletePod(curPod)
+		return
 	}
-
 	rm.enqueueController(rc)
 	// Only need to get the old controller if the labels changed.
 	if !reflect.DeepEqual(curPod.Labels, oldPod.Labels) {
@@ -372,20 +363,14 @@ func (rm *ReplicationManager) deletePod(obj interface{}) {
 			return
 		}
 	}
+	glog.V(4).Infof("Pod %s/%s deleted through %v, timestamp %+v, labels %+v.", pod.Namespace, pod.Name, utilruntime.GetCaller(), pod.DeletionTimestamp, pod.Labels)
 	if rc := rm.getPodController(pod); rc != nil {
 		rcKey, err := controller.KeyFunc(rc)
 		if err != nil {
 			glog.Errorf("Couldn't get key for replication controller %#v: %v", rc, err)
 			return
 		}
-		// This method only manages expectations for the case where a pod is
-		// deleted without a grace period.
-		if pod.DeletionTimestamp == nil {
-			glog.V(4).Infof("Received new delete for rc %v, pod %v", rcKey, pod.Name)
-			rm.expectations.DeletionObserved(rcKey)
-		} else {
-			glog.V(4).Infof("Received delete for rc %v pod %v with non nil deletion timestamp %+v. Not counting it as a new deletion.", rcKey, pod.Name, pod.DeletionTimestamp)
-		}
+		rm.expectations.DeletionObserved(rcKey, controller.PodKey(pod))
 		rm.enqueueController(rc)
 	}
 }
@@ -438,6 +423,11 @@ func (rm *ReplicationManager) manageReplicas(filteredPods []*api.Pod, rc *api.Re
 		if diff > rm.burstReplicas {
 			diff = rm.burstReplicas
 		}
+		// TODO: Track UIDs of creates just like deletes. The problem currently
+		// is we'd need to wait on the result of a create to record the pod's
+		// UID, which would require locking *across* the create, which will turn
+		// into a performance bottleneck. We should generate a UID for the pod
+		// beforehand and store it via ExpectCreations.
 		rm.expectations.ExpectCreations(rcKey, diff)
 		wait := sync.WaitGroup{}
 		wait.Add(diff)
@@ -458,7 +448,6 @@ func (rm *ReplicationManager) manageReplicas(filteredPods []*api.Pod, rc *api.Re
 		if diff > rm.burstReplicas {
 			diff = rm.burstReplicas
 		}
-		rm.expectations.ExpectDeletions(rcKey, diff)
 		glog.V(2).Infof("Too many %q/%q replicas, need %d, deleting %d", rc.Namespace, rc.Name, rc.Spec.Replicas, diff)
 		// No need to sort pods if we are about to delete all of them
 		if rc.Spec.Replicas != 0 {
@@ -467,7 +456,20 @@ func (rm *ReplicationManager) manageReplicas(filteredPods []*api.Pod, rc *api.Re
 			// in the earlier stages whenever possible.
 			sort.Sort(controller.ActivePods(filteredPods))
 		}
-
+		// Snapshot the UIDs (ns/name) of the pods we're expecting to see
+		// deleted, so we know to record their expectations exactly once either
+		// when we see it as an update of the deletion timestamp, or as a delete.
+		// Note that if the labels on a pod/rc change in a way that the pod gets
+		// orphaned, the rs will only wake up after the expectations have
+		// expired even if other pods are deleted.
+		deletedPodKeys := []string{}
+		for i := 0; i < diff; i++ {
+			deletedPodKeys = append(deletedPodKeys, controller.PodKey(filteredPods[i]))
+		}
+		// We use pod namespace/name as a UID to wait for deletions, so if the
+		// labels on a pod/rc change in a way that the pod gets orphaned, the
+		// rc will only wake up after the expectation has expired.
+		rm.expectations.ExpectDeletions(rcKey, deletedPodKeys)
 		wait := sync.WaitGroup{}
 		wait.Add(diff)
 		for i := 0; i < diff; i++ {
@@ -475,8 +477,9 @@ func (rm *ReplicationManager) manageReplicas(filteredPods []*api.Pod, rc *api.Re
 				defer wait.Done()
 				if err := rm.podControl.DeletePod(rc.Namespace, filteredPods[ix].Name, rc); err != nil {
 					// Decrement the expected number of deletes because the informer won't observe this deletion
-					glog.V(2).Infof("Failed deletion, decrementing expectations for controller %q/%q", rc.Namespace, rc.Name)
-					rm.expectations.DeletionObserved(rcKey)
+					podKey := controller.PodKey(filteredPods[ix])
+					glog.V(2).Infof("Failed to delete %v, decrementing expectations for controller %q/%q", podKey, rc.Namespace, rc.Name)
+					rm.expectations.DeletionObserved(rcKey, podKey)
 					utilruntime.HandleError(err)
 				}
 			}(i)

pkg/controller/replication/replication_controller_test.go

@@ -22,6 +22,7 @@ import (
 	"fmt"
 	"math/rand"
 	"net/http/httptest"
+	"strings"
 	"testing"
 	"time"
 
@@ -638,6 +639,7 @@ func TestControllerUpdateStatusWithFailure(t *testing.T) {
 	}
 }
 
+// TODO: This test is too hairy for a unittest. It should be moved to an E2E suite.
 func doTestControllerBurstReplicas(t *testing.T, burstReplicas, numReplicas int) {
 	c := clientset.NewForConfigOrDie(&restclient.Config{Host: "", ContentConfig: restclient.ContentConfig{GroupVersion: testapi.Default.GroupVersion()}})
 	fakePodControl := controller.FakePodControl{}
@@ -698,9 +700,27 @@ func doTestControllerBurstReplicas(t *testing.T, burstReplicas, numReplicas int)
 					expectedPods = burstReplicas
 				}
 				validateSyncReplication(t, &fakePodControl, 0, expectedPods)
-				for i := 0; i < expectedPods-1; i++ {
-					manager.podStore.Store.Delete(&pods.Items[i])
-					manager.deletePod(&pods.Items[i])
+
+				// To accurately simulate a watch we must delete the exact pods
+				// the rc is waiting for.
+				expectedDels := manager.expectations.GetUIDs(getKey(controllerSpec, t))
+				podsToDelete := []*api.Pod{}
+				for _, key := range expectedDels.List() {
+					nsName := strings.Split(key, "/")
+					podsToDelete = append(podsToDelete, &api.Pod{
+						ObjectMeta: api.ObjectMeta{
+							Name:      nsName[1],
+							Namespace: nsName[0],
+							Labels:    controllerSpec.Spec.Selector,
+						},
+					})
+				}
+				// Don't delete all pods because we confirm that the last pod
+				// has exactly one expectation at the end, to verify that we
+				// don't double delete.
+				for i := range podsToDelete[1:] {
+					manager.podStore.Delete(podsToDelete[i])
+					manager.deletePod(podsToDelete[i])
 				}
 				podExp, exists, err := manager.expectations.GetExpectations(rcKey)
 				if !exists || err != nil {
@@ -723,8 +743,20 @@ func doTestControllerBurstReplicas(t *testing.T, burstReplicas, numReplicas int)
 				manager.podStore.Store.Add(&pods.Items[expectedPods-1])
 				manager.addPod(&pods.Items[expectedPods-1])
 			} else {
-				manager.podStore.Store.Delete(&pods.Items[expectedPods-1])
-				manager.deletePod(&pods.Items[expectedPods-1])
+				expectedDel := manager.expectations.GetUIDs(getKey(controllerSpec, t))
+				if expectedDel.Len() != 1 {
+					t.Fatalf("Waiting on unexpected number of deletes.")
+				}
+				nsName := strings.Split(expectedDel.List()[0], "/")
+				lastPod := &api.Pod{
+					ObjectMeta: api.ObjectMeta{
+						Name:      nsName[1],
+						Namespace: nsName[0],
+						Labels:    controllerSpec.Spec.Selector,
+					},
+				}
+				manager.podStore.Store.Delete(lastPod)
+				manager.deletePod(lastPod)
 			}
 			pods.Items = pods.Items[expectedPods:]
 		}
@@ -771,14 +803,14 @@ func TestRCSyncExpectations(t *testing.T) {
 	manager.podStore.Store.Add(&pods.Items[0])
 	postExpectationsPod := pods.Items[1]
 
-	manager.expectations = FakeRCExpectations{
+	manager.expectations = controller.NewUIDTrackingControllerExpectations(FakeRCExpectations{
 		controller.NewControllerExpectations(), true, func() {
 			// If we check active pods before checking expectataions, the rc
 			// will create a new replica because it doesn't see this pod, but
 			// has fulfilled its expectations.
 			manager.podStore.Store.Add(&postExpectationsPod)
 		},
-	}
+	})
 	manager.syncReplicationController(getKey(controllerSpec, t))
 	validateSyncReplication(t, &fakePodControl, 0, 0)
 }
@@ -906,7 +938,7 @@ func TestDeletionTimestamp(t *testing.T) {
 	}
 	pod := newPodList(nil, 1, api.PodPending, controllerSpec).Items[0]
 	pod.DeletionTimestamp = &unversioned.Time{time.Now()}
-	manager.expectations.SetExpectations(rcKey, 0, 1)
+	manager.expectations.ExpectDeletions(rcKey, []string{controller.PodKey(&pod)})
 
 	// A pod added with a deletion timestamp should decrement deletions, not creations.
 	manager.addPod(&pod)
@@ -925,7 +957,7 @@ func TestDeletionTimestamp(t *testing.T) {
 	// An update from no deletion timestamp to having one should be treated
 	// as a deletion.
 	oldPod := newPodList(nil, 1, api.PodPending, controllerSpec).Items[0]
-	manager.expectations.SetExpectations(rcKey, 0, 1)
+	manager.expectations.ExpectDeletions(rcKey, []string{controller.PodKey(&pod)})
 	manager.updatePod(&oldPod, &pod)
 
 	queueRC, _ = manager.queue.Get()
@@ -941,7 +973,14 @@ func TestDeletionTimestamp(t *testing.T) {
 
 	// An update to the pod (including an update to the deletion timestamp)
 	// should not be counted as a second delete.
-	manager.expectations.SetExpectations(rcKey, 0, 1)
+	secondPod := &api.Pod{
+		ObjectMeta: api.ObjectMeta{
+			Namespace: pod.Namespace,
+			Name:      "secondPod",
+			Labels:    pod.Labels,
+		},
+	}
+	manager.expectations.ExpectDeletions(rcKey, []string{controller.PodKey(secondPod)})
 	oldPod.DeletionTimestamp = &unversioned.Time{time.Now()}
 	manager.updatePod(&oldPod, &pod)
 
@@ -958,9 +997,8 @@ func TestDeletionTimestamp(t *testing.T) {
 		t.Fatalf("Wrong expectations %+v", podExp)
 	}
 
-	// A pod with a nil timestamp should be counted as a deletion.
-	pod.DeletionTimestamp = nil
-	manager.deletePod(&pod)
+	// Deleting the second pod should clear expectations.
+	manager.deletePod(secondPod)
 
 	queueRC, _ = manager.queue.Get()
 	if queueRC != rcKey {

pkg/util/runtime/runtime.go

@@ -76,3 +76,14 @@ func HandleError(err error) {
 func logError(err error) {
 	glog.ErrorDepth(2, err)
 }
+
+// GetCaller returns the caller of the function that calls it.
+func GetCaller() string {
+	var pc [1]uintptr
+	runtime.Callers(3, pc[:])
+	f := runtime.FuncForPC(pc[0])
+	if f == nil {
+		return fmt.Sprintf("Unable to find caller")
+	}
+	return f.Name()
+}