RC/RS: Use ControllerRef to route watch events.

This is part of the completion of ControllerRef, as described here: https://github.com/kubernetes/community/blob/master/contributors/design-proposals/controller-ref.md#watches This also removes the need for the Pod->Controller mapping cache in RC and RS. This mapping is now persisted in the Pod's ControllerRef instead.
2025-11-02 03:08:15 +00:00 · 2017-02-23 08:58:28 -08:00
parent 298db3a0c3
commit ca13b9e532
13 changed files with 486 additions and 416 deletions
--- a/pkg/controller/replicaset/BUILD
+++ b/pkg/controller/replicaset/BUILD
@@ -32,7 +32,6 @@ go_library(
        "//vendor:k8s.io/apimachinery/pkg/api/errors",
        "//vendor:k8s.io/apimachinery/pkg/apis/meta/v1",
        "//vendor:k8s.io/apimachinery/pkg/labels",
-        "//vendor:k8s.io/apimachinery/pkg/runtime/schema",
        "//vendor:k8s.io/apimachinery/pkg/util/runtime",
        "//vendor:k8s.io/apimachinery/pkg/util/wait",
        "//vendor:k8s.io/client-go/kubernetes/typed/core/v1",
--- a/pkg/controller/replicaset/replica_set.go
+++ b/pkg/controller/replicaset/replica_set.go
@@ -29,7 +29,6 @@ import (
 	"k8s.io/apimachinery/pkg/api/errors"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/labels"
-	"k8s.io/apimachinery/pkg/runtime/schema"
 	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
 	"k8s.io/apimachinery/pkg/util/wait"
 	v1core "k8s.io/client-go/kubernetes/typed/core/v1"
@@ -59,9 +58,8 @@ const (
 	statusUpdateRetries = 1
 )

-func getRSKind() schema.GroupVersionKind {
-	return v1beta1.SchemeGroupVersion.WithKind("ReplicaSet")
-}
+// controllerKind contains the schema.GroupVersionKind for this controller type.
+var controllerKind = v1beta1.SchemeGroupVersion.WithKind("ReplicaSet")

 // ReplicaSetController is responsible for synchronizing ReplicaSet objects stored
 // in the system with actual running pods.
@@ -90,14 +88,12 @@ type ReplicaSetController struct {
 	// Added as a member to the struct to allow injection for testing.
 	podListerSynced cache.InformerSynced

-	lookupCache *controller.MatchingCache
-
 	// Controllers that need to be synced
 	queue workqueue.RateLimitingInterface
 }

 // NewReplicaSetController configures a replica set controller with the specified event recorder
-func NewReplicaSetController(rsInformer extensionsinformers.ReplicaSetInformer, podInformer coreinformers.PodInformer, kubeClient clientset.Interface, burstReplicas int, lookupCacheSize int) *ReplicaSetController {
+func NewReplicaSetController(rsInformer extensionsinformers.ReplicaSetInformer, podInformer coreinformers.PodInformer, kubeClient clientset.Interface, burstReplicas int) *ReplicaSetController {
 	if kubeClient != nil && kubeClient.Core().RESTClient().GetRateLimiter() != nil {
 		metrics.RegisterMetricAndTrackRateLimiterUsage("replicaset_controller", kubeClient.Core().RESTClient().GetRateLimiter())
 	}
@@ -139,7 +135,6 @@ func NewReplicaSetController(rsInformer extensionsinformers.ReplicaSetInformer,
 	rsc.podListerSynced = podInformer.Informer().HasSynced

 	rsc.syncHandler = rsc.syncReplicaSet
-	rsc.lookupCache = controller.NewMatchingCache(lookupCacheSize)

 	return rsc
 }
@@ -172,46 +167,19 @@ func (rsc *ReplicaSetController) Run(workers int, stopCh <-chan struct{}) {
 	glog.Infof("Shutting down ReplicaSet Controller")
 }

-// getPodReplicaSet returns the replica set managing the given pod.
-// TODO: Surface that we are ignoring multiple replica sets for a single pod.
-// TODO: use ownerReference.Controller to determine if the rs controls the pod.
-func (rsc *ReplicaSetController) getPodReplicaSet(pod *v1.Pod) *extensions.ReplicaSet {
-	// look up in the cache, if cached and the cache is valid, just return cached value
-	if obj, cached := rsc.lookupCache.GetMatchingObject(pod); cached {
-		rs, ok := obj.(*extensions.ReplicaSet)
-		if !ok {
-			// This should not happen
-			utilruntime.HandleError(fmt.Errorf("lookup cache does not return a ReplicaSet object"))
-			return nil
-		}
-		if cached && rsc.isCacheValid(pod, rs) {
-			return rs
-		}
-	}
-
-	// if not cached or cached value is invalid, search all the rs to find the matching one, and update cache
+// getPodReplicaSets returns a list of ReplicaSets matching the given pod.
+func (rsc *ReplicaSetController) getPodReplicaSets(pod *v1.Pod) []*extensions.ReplicaSet {
 	rss, err := rsc.rsLister.GetPodReplicaSets(pod)
 	if err != nil {
 		glog.V(4).Infof("No ReplicaSets found for pod %v, ReplicaSet controller will avoid syncing", pod.Name)
 		return nil
 	}
-	// In theory, overlapping ReplicaSets is user error. This sorting will not prevent
-	// oscillation of replicas in all cases, eg:
-	// rs1 (older rs): [(k1=v1)], replicas=1 rs2: [(k2=v2)], replicas=2
-	// pod: [(k1:v1), (k2:v2)] will wake both rs1 and rs2, and we will sync rs1.
-	// pod: [(k2:v2)] will wake rs2 which creates a new replica.
 	if len(rss) > 1 {
-		// More than two items in this list indicates user error. If two replicasets
-		// overlap, sort by creation timestamp, subsort by name, then pick
-		// the first.
+		// ControllerRef will ensure we don't do anything crazy, but more than one
+		// item in this list nevertheless constitutes user error.
 		utilruntime.HandleError(fmt.Errorf("user error! more than one ReplicaSet is selecting pods with labels: %+v", pod.Labels))
-		sort.Sort(controller.ReplicaSetsByCreationTimestamp(rss))
 	}
-
-	// update lookup cache
-	rsc.lookupCache.Update(pod, rss[0])
-
-	return rss[0]
+	return rss
 }

 // callback when RS is updated
@@ -219,21 +187,6 @@ func (rsc *ReplicaSetController) updateRS(old, cur interface{}) {
 	oldRS := old.(*extensions.ReplicaSet)
 	curRS := cur.(*extensions.ReplicaSet)

-	// We should invalidate the whole lookup cache if a RS's selector has been updated.
-	//
-	// Imagine that you have two RSs:
-	// * old RS1
-	// * new RS2
-	// You also have a pod that is attached to RS2 (because it doesn't match RS1 selector).
-	// Now imagine that you are changing RS1 selector so that it is now matching that pod,
-	// in such case we must invalidate the whole cache so that pod could be adopted by RS1
-	//
-	// This makes the lookup cache less helpful, but selector update does not happen often,
-	// so it's not a big problem
-	if !reflect.DeepEqual(oldRS.Spec.Selector, curRS.Spec.Selector) {
-		rsc.lookupCache.InvalidateAll()
-	}
-
 	// You might imagine that we only really need to enqueue the
 	// replica set when Spec changes, but it is safer to sync any
 	// time this function is triggered. That way a full informer
@@ -252,57 +205,44 @@ func (rsc *ReplicaSetController) updateRS(old, cur interface{}) {
 	rsc.enqueueReplicaSet(cur)
 }

-// isCacheValid check if the cache is valid
-func (rsc *ReplicaSetController) isCacheValid(pod *v1.Pod, cachedRS *extensions.ReplicaSet) bool {
-	_, err := rsc.rsLister.ReplicaSets(cachedRS.Namespace).Get(cachedRS.Name)
-	// rs has been deleted or updated, cache is invalid
-	if err != nil || !isReplicaSetMatch(pod, cachedRS) {
-		return false
-	}
-	return true
-}
-
-// isReplicaSetMatch take a Pod and ReplicaSet, return whether the Pod and ReplicaSet are matching
-// TODO(mqliang): This logic is a copy from GetPodReplicaSets(), remove the duplication
-func isReplicaSetMatch(pod *v1.Pod, rs *extensions.ReplicaSet) bool {
-	if rs.Namespace != pod.Namespace {
-		return false
-	}
-	selector, err := metav1.LabelSelectorAsSelector(rs.Spec.Selector)
-	if err != nil {
-		err = fmt.Errorf("invalid selector: %v", err)
-		return false
-	}
-
-	// If a ReplicaSet with a nil or empty selector creeps in, it should match nothing, not everything.
-	if selector.Empty() || !selector.Matches(labels.Set(pod.Labels)) {
-		return false
-	}
-	return true
-}
-
-// When a pod is created, enqueue the replica set that manages it and update it's expectations.
+// When a pod is created, enqueue the replica set that manages it and update its expectations.
 func (rsc *ReplicaSetController) addPod(obj interface{}) {
 	pod := obj.(*v1.Pod)
 	glog.V(4).Infof("Pod %s created: %#v.", pod.Name, pod)

-	rs := rsc.getPodReplicaSet(pod)
-	if rs == nil {
-		return
-	}
-	rsKey, err := controller.KeyFunc(rs)
-	if err != nil {
-		utilruntime.HandleError(fmt.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.
 		rsc.deletePod(pod)
 		return
 	}
-	rsc.expectations.CreationObserved(rsKey)
-	rsc.enqueueReplicaSet(rs)
+
+	// If it has a ControllerRef, that's all that matters.
+	if controllerRef := controller.GetControllerOf(pod); controllerRef != nil {
+		if controllerRef.Kind != controllerKind.Kind {
+			// It's controlled by a different type of controller.
+			return
+		}
+		rs, err := rsc.rsLister.ReplicaSets(pod.Namespace).Get(controllerRef.Name)
+		if err != nil {
+			return
+		}
+		rsKey, err := controller.KeyFunc(rs)
+		if err != nil {
+			return
+		}
+		rsc.expectations.CreationObserved(rsKey)
+		rsc.enqueueReplicaSet(rs)
+		return
+	}
+
+	// Otherwise, it's an orphan. Get a list of all matching ReplicaSets and sync
+	// them to see if anyone wants to adopt it.
+	// DO NOT observe creation because no controller should be waiting for an
+	// orphan.
+	for _, rs := range rsc.getPodReplicaSets(pod) {
+		rsc.enqueueReplicaSet(rs)
+	}
 }

 // When a pod is updated, figure out what replica set/s manage it and wake them
@@ -317,6 +257,7 @@ func (rsc *ReplicaSetController) updatePod(old, cur interface{}) {
 		return
 	}
 	glog.V(4).Infof("Pod %s updated, objectMeta %+v -> %+v.", curPod.Name, oldPod.ObjectMeta, curPod.ObjectMeta)
+
 	labelChanged := !reflect.DeepEqual(curPod.Labels, oldPod.Labels)
 	if curPod.DeletionTimestamp != nil {
 		// when a pod is deleted gracefully it's deletion timestamp is first modified to reflect a grace period,
@@ -332,18 +273,29 @@ func (rsc *ReplicaSetController) updatePod(old, cur interface{}) {
 		return
 	}

-	// Enqueue the oldRC before the curRC to give curRC a chance to adopt the oldPod.
-	if labelChanged {
-		// If the old and new ReplicaSet are the same, the first one that syncs
-		// will set expectations preventing any damage from the second.
-		if oldRS := rsc.getPodReplicaSet(oldPod); oldRS != nil {
-			rsc.enqueueReplicaSet(oldRS)
+	curControllerRef := controller.GetControllerOf(curPod)
+	oldControllerRef := controller.GetControllerOf(oldPod)
+	controllerRefChanged := !reflect.DeepEqual(curControllerRef, oldControllerRef)
+	if controllerRefChanged &&
+		oldControllerRef != nil && oldControllerRef.Kind == controllerKind.Kind {
+		// The ControllerRef was changed. Sync the old controller, if any.
+		rs, err := rsc.rsLister.ReplicaSets(oldPod.Namespace).Get(oldControllerRef.Name)
+		if err == nil {
+			rsc.enqueueReplicaSet(rs)
 		}
 	}

-	changedToReady := !v1.IsPodReady(oldPod) && v1.IsPodReady(curPod)
-	if curRS := rsc.getPodReplicaSet(curPod); curRS != nil {
-		rsc.enqueueReplicaSet(curRS)
+	// If it has a ControllerRef, that's all that matters.
+	if curControllerRef != nil {
+		if curControllerRef.Kind != controllerKind.Kind {
+			// It's controlled by a different type of controller.
+			return
+		}
+		rs, err := rsc.rsLister.ReplicaSets(curPod.Namespace).Get(curControllerRef.Name)
+		if err != nil {
+			return
+		}
+		rsc.enqueueReplicaSet(rs)
 		// TODO: MinReadySeconds in the Pod will generate an Available condition to be added in
 		// the Pod status which in turn will trigger a requeue of the owning replica set thus
 		// having its status updated with the newly available replica. For now, we can fake the
@@ -351,9 +303,18 @@ func (rsc *ReplicaSetController) updatePod(old, cur interface{}) {
 		// a Pod transitioned to Ready.
 		// Note that this still suffers from #29229, we are just moving the problem one level
 		// "closer" to kubelet (from the deployment to the replica set controller).
-		if changedToReady && curRS.Spec.MinReadySeconds > 0 {
-			glog.V(2).Infof("ReplicaSet %q will be enqueued after %ds for availability check", curRS.Name, curRS.Spec.MinReadySeconds)
-			rsc.enqueueReplicaSetAfter(curRS, time.Duration(curRS.Spec.MinReadySeconds)*time.Second)
+		if !v1.IsPodReady(oldPod) && v1.IsPodReady(curPod) && rs.Spec.MinReadySeconds > 0 {
+			glog.V(2).Infof("ReplicaSet %q will be enqueued after %ds for availability check", rs.Name, rs.Spec.MinReadySeconds)
+			rsc.enqueueReplicaSetAfter(rs, time.Duration(rs.Spec.MinReadySeconds)*time.Second)
+		}
+		return
+	}
+
+	// Otherwise, it's an orphan. If anything changed, sync matching controllers
+	// to see if anyone wants to adopt it now.
+	if labelChanged || controllerRefChanged {
+		for _, rs := range rsc.getPodReplicaSets(curPod) {
+			rsc.enqueueReplicaSet(rs)
 		}
 	}
 }
@@ -370,41 +331,46 @@ func (rsc *ReplicaSetController) deletePod(obj interface{}) {
 	if !ok {
 		tombstone, ok := obj.(cache.DeletedFinalStateUnknown)
 		if !ok {
-			utilruntime.HandleError(fmt.Errorf("Couldn't get object from tombstone %+v", obj))
+			utilruntime.HandleError(fmt.Errorf("couldn't get object from tombstone %+v", obj))
 			return
 		}
 		pod, ok = tombstone.Obj.(*v1.Pod)
 		if !ok {
-			utilruntime.HandleError(fmt.Errorf("Tombstone contained object that is not a pod %#v", obj))
+			utilruntime.HandleError(fmt.Errorf("tombstone contained object that is not a pod %#v", obj))
 			return
 		}
 	}
 	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 {
-			utilruntime.HandleError(fmt.Errorf("Couldn't get key for ReplicaSet %#v: %v", rs, err))
-			return
-		}
-		rsc.expectations.DeletionObserved(rsKey, controller.PodKey(pod))
-		rsc.enqueueReplicaSet(rs)
+
+	controllerRef := controller.GetControllerOf(pod)
+	if controllerRef == nil {
+		// No controller should care about orphans being deleted.
+		return
 	}
+	if controllerRef.Kind != controllerKind.Kind {
+		// It's controlled by a different type of controller.
+		return
+	}
+
+	rs, err := rsc.rsLister.ReplicaSets(pod.Namespace).Get(controllerRef.Name)
+	if err != nil {
+		return
+	}
+	rsKey, err := controller.KeyFunc(rs)
+	if err != nil {
+		return
+	}
+	rsc.expectations.DeletionObserved(rsKey, controller.PodKey(pod))
+	rsc.enqueueReplicaSet(rs)
 }

 // obj could be an *extensions.ReplicaSet, or a DeletionFinalStateUnknown marker item.
 func (rsc *ReplicaSetController) enqueueReplicaSet(obj interface{}) {
 	key, err := controller.KeyFunc(obj)
 	if err != nil {
-		utilruntime.HandleError(fmt.Errorf("Couldn't get key for object %+v: %v", obj, err))
+		utilruntime.HandleError(fmt.Errorf("couldn't get key for object %+v: %v", obj, err))
 		return
 	}
-
-	// TODO: Handle overlapping replica sets better. Either disallow them at admission time or
-	// deterministically avoid syncing replica sets that fight over pods. Currently, we only
-	// ensure that the same replica set is synced for a given pod. When we periodically relist
-	// all replica sets there will still be some replica instability. One way to handle this is
-	// by querying the store for all replica sets that this replica set overlaps, as well as all
-	// replica sets that overlap this ReplicaSet, and sorting them.
 	rsc.queue.Add(key)
 }

@@ -412,16 +378,9 @@ func (rsc *ReplicaSetController) enqueueReplicaSet(obj interface{}) {
 func (rsc *ReplicaSetController) enqueueReplicaSetAfter(obj interface{}, after time.Duration) {
 	key, err := controller.KeyFunc(obj)
 	if err != nil {
-		utilruntime.HandleError(fmt.Errorf("Couldn't get key for object %+v: %v", obj, err))
+		utilruntime.HandleError(fmt.Errorf("couldn't get key for object %+v: %v", obj, err))
 		return
 	}
-
-	// TODO: Handle overlapping replica sets better. Either disallow them at admission time or
-	// deterministically avoid syncing replica sets that fight over pods. Currently, we only
-	// ensure that the same replica set is synced for a given pod. When we periodically relist
-	// all replica sets there will still be some replica instability. One way to handle this is
-	// by querying the store for all replica sets that this replica set overlaps, as well as all
-	// replica sets that overlap this ReplicaSet, and sorting them.
 	rsc.queue.AddAfter(key, after)
 }

@@ -483,8 +442,8 @@ func (rsc *ReplicaSetController) manageReplicas(filteredPods []*v1.Pod, rs *exte
 				var err error
 				boolPtr := func(b bool) *bool { return &b }
 				controllerRef := &metav1.OwnerReference{
-					APIVersion:         getRSKind().GroupVersion().String(),
-					Kind:               getRSKind().Kind,
+					APIVersion:         controllerKind.GroupVersion().String(),
+					Kind:               controllerKind.Kind,
 					Name:               rs.Name,
 					UID:                rs.UID,
 					BlockOwnerDeletion: boolPtr(true),
@@ -592,7 +551,7 @@ func (rsc *ReplicaSetController) syncReplicaSet(key string) error {
 	if err != nil {
 		return err
 	}
-	cm := controller.NewPodControllerRefManager(rsc.podControl, rs, selector, getRSKind())
+	cm := controller.NewPodControllerRefManager(rsc.podControl, rs, selector, controllerKind)
 	filteredPods, err = cm.ClaimPods(pods)
 	if err != nil {
 		// Something went wrong with adoption or release.
--- a/pkg/controller/replicaset/replica_set_test.go
+++ b/pkg/controller/replicaset/replica_set_test.go
@@ -51,7 +51,7 @@ import (
 	"k8s.io/kubernetes/pkg/securitycontext"
 )

-func testNewReplicaSetControllerFromClient(client clientset.Interface, stopCh chan struct{}, burstReplicas int, lookupCacheSize int) (*ReplicaSetController, informers.SharedInformerFactory) {
+func testNewReplicaSetControllerFromClient(client clientset.Interface, stopCh chan struct{}, burstReplicas int) (*ReplicaSetController, informers.SharedInformerFactory) {
 	informers := informers.NewSharedInformerFactory(client, controller.NoResyncPeriodFunc())

 	ret := NewReplicaSetController(
@@ -59,7 +59,6 @@ func testNewReplicaSetControllerFromClient(client clientset.Interface, stopCh ch
 		informers.Core().V1().Pods(),
 		client,
 		burstReplicas,
-		lookupCacheSize,
 	)

 	ret.podListerSynced = alwaysReady
@@ -216,7 +215,7 @@ func TestSyncReplicaSetDoesNothing(t *testing.T) {
 	fakePodControl := controller.FakePodControl{}
 	stopCh := make(chan struct{})
 	defer close(stopCh)
-	manager, informers := testNewReplicaSetControllerFromClient(client, stopCh, BurstReplicas, 0)
+	manager, informers := testNewReplicaSetControllerFromClient(client, stopCh, BurstReplicas)

 	// 2 running pods, a controller with 2 replicas, sync is a no-op
 	labelMap := map[string]string{"foo": "bar"}
@@ -234,7 +233,7 @@ func TestSyncReplicaSetDeletes(t *testing.T) {
 	fakePodControl := controller.FakePodControl{}
 	stopCh := make(chan struct{})
 	defer close(stopCh)
-	manager, informers := testNewReplicaSetControllerFromClient(client, stopCh, BurstReplicas, 0)
+	manager, informers := testNewReplicaSetControllerFromClient(client, stopCh, BurstReplicas)
 	manager.podControl = &fakePodControl

 	// 2 running pods and a controller with 1 replica, one pod delete expected
@@ -252,7 +251,7 @@ func TestDeleteFinalStateUnknown(t *testing.T) {
 	fakePodControl := controller.FakePodControl{}
 	stopCh := make(chan struct{})
 	defer close(stopCh)
-	manager, informers := testNewReplicaSetControllerFromClient(client, stopCh, BurstReplicas, 0)
+	manager, informers := testNewReplicaSetControllerFromClient(client, stopCh, BurstReplicas)
 	manager.podControl = &fakePodControl

 	received := make(chan string)
@@ -286,7 +285,7 @@ func TestSyncReplicaSetCreates(t *testing.T) {
 	client := clientset.NewForConfigOrDie(&restclient.Config{Host: "", ContentConfig: restclient.ContentConfig{GroupVersion: &api.Registry.GroupOrDie(v1.GroupName).GroupVersion}})
 	stopCh := make(chan struct{})
 	defer close(stopCh)
-	manager, informers := testNewReplicaSetControllerFromClient(client, stopCh, BurstReplicas, 0)
+	manager, informers := testNewReplicaSetControllerFromClient(client, stopCh, BurstReplicas)

 	// A controller with 2 replicas and no pods in the store, 2 creates expected
 	labelMap := map[string]string{"foo": "bar"}
@@ -311,7 +310,7 @@ func TestStatusUpdatesWithoutReplicasChange(t *testing.T) {
 	client := clientset.NewForConfigOrDie(&restclient.Config{Host: testServer.URL, ContentConfig: restclient.ContentConfig{GroupVersion: &api.Registry.GroupOrDie(v1.GroupName).GroupVersion}})
 	stopCh := make(chan struct{})
 	defer close(stopCh)
-	manager, informers := testNewReplicaSetControllerFromClient(client, stopCh, BurstReplicas, 0)
+	manager, informers := testNewReplicaSetControllerFromClient(client, stopCh, BurstReplicas)

 	// Steady state for the ReplicaSet, no Status.Replicas updates expected
 	activePods := 5
@@ -356,7 +355,7 @@ func TestControllerUpdateReplicas(t *testing.T) {
 	client := clientset.NewForConfigOrDie(&restclient.Config{Host: testServer.URL, ContentConfig: restclient.ContentConfig{GroupVersion: &api.Registry.GroupOrDie(v1.GroupName).GroupVersion}})
 	stopCh := make(chan struct{})
 	defer close(stopCh)
-	manager, informers := testNewReplicaSetControllerFromClient(client, stopCh, BurstReplicas, 0)
+	manager, informers := testNewReplicaSetControllerFromClient(client, stopCh, BurstReplicas)

 	// Insufficient number of pods in the system, and Status.Replicas is wrong;
 	// Status.Replica should update to match number of pods in system, 1 new pod should be created.
@@ -405,7 +404,7 @@ func TestSyncReplicaSetDormancy(t *testing.T) {
 	fakePodControl := controller.FakePodControl{}
 	stopCh := make(chan struct{})
 	defer close(stopCh)
-	manager, informers := testNewReplicaSetControllerFromClient(client, stopCh, BurstReplicas, 0)
+	manager, informers := testNewReplicaSetControllerFromClient(client, stopCh, BurstReplicas)

 	manager.podControl = &fakePodControl

@@ -461,7 +460,7 @@ func TestSyncReplicaSetDormancy(t *testing.T) {
 func TestPodControllerLookup(t *testing.T) {
 	stopCh := make(chan struct{})
 	defer close(stopCh)
-	manager, informers := testNewReplicaSetControllerFromClient(clientset.NewForConfigOrDie(&restclient.Config{Host: "", ContentConfig: restclient.ContentConfig{GroupVersion: &api.Registry.GroupOrDie(v1.GroupName).GroupVersion}}), stopCh, BurstReplicas, 0)
+	manager, informers := testNewReplicaSetControllerFromClient(clientset.NewForConfigOrDie(&restclient.Config{Host: "", ContentConfig: restclient.ContentConfig{GroupVersion: &api.Registry.GroupOrDie(v1.GroupName).GroupVersion}}), stopCh, BurstReplicas)
 	testCases := []struct {
 		inRSs     []*extensions.ReplicaSet
 		pod       *v1.Pod
@@ -509,7 +508,12 @@ func TestPodControllerLookup(t *testing.T) {
 		for _, r := range c.inRSs {
 			informers.Extensions().V1beta1().ReplicaSets().Informer().GetIndexer().Add(r)
 		}
-		if rs := manager.getPodReplicaSet(c.pod); rs != nil {
+		if rss := manager.getPodReplicaSets(c.pod); rss != nil {
+			if len(rss) != 1 {
+				t.Errorf("len(rss) = %v, want %v", len(rss), 1)
+				continue
+			}
+			rs := rss[0]
 			if c.outRSName != rs.Name {
 				t.Errorf("Got replica set %+v expected %+v", rs.Name, c.outRSName)
 			}
@@ -536,7 +540,6 @@ func TestWatchControllers(t *testing.T) {
 		informers.Core().V1().Pods(),
 		client,
 		BurstReplicas,
-		0,
 	)
 	informers.Start(stopCh)

@@ -581,7 +584,7 @@ func TestWatchPods(t *testing.T) {
 	stopCh := make(chan struct{})
 	defer close(stopCh)

-	manager, informers := testNewReplicaSetControllerFromClient(client, stopCh, BurstReplicas, 0)
+	manager, informers := testNewReplicaSetControllerFromClient(client, stopCh, BurstReplicas)

 	// Put one ReplicaSet into the shared informer
 	labelMap := map[string]string{"foo": "bar"}
@@ -627,7 +630,7 @@ func TestWatchPods(t *testing.T) {
 func TestUpdatePods(t *testing.T) {
 	stopCh := make(chan struct{})
 	defer close(stopCh)
-	manager, informers := testNewReplicaSetControllerFromClient(fake.NewSimpleClientset(), stopCh, BurstReplicas, 0)
+	manager, informers := testNewReplicaSetControllerFromClient(fake.NewSimpleClientset(), stopCh, BurstReplicas)

 	received := make(chan string)

@@ -656,16 +659,19 @@ func TestUpdatePods(t *testing.T) {
 	testRSSpec2.Name = "barfoo"
 	informers.Extensions().V1beta1().ReplicaSets().Informer().GetIndexer().Add(&testRSSpec2)

-	// case 1: We put in the podLister a pod with labels matching testRSSpec1,
-	// then update its labels to match testRSSpec2.  We expect to receive a sync
-	// request for both replica sets.
+	isController := true
+	controllerRef1 := metav1.OwnerReference{UID: testRSSpec1.UID, APIVersion: "v1", Kind: "ReplicaSet", Name: testRSSpec1.Name, Controller: &isController}
+	controllerRef2 := metav1.OwnerReference{UID: testRSSpec2.UID, APIVersion: "v1", Kind: "ReplicaSet", Name: testRSSpec2.Name, Controller: &isController}
+
+	// case 1: Pod with a ControllerRef
 	pod1 := newPodList(informers.Core().V1().Pods().Informer().GetIndexer(), 1, v1.PodRunning, labelMap1, testRSSpec1, "pod").Items[0]
+	pod1.OwnerReferences = []metav1.OwnerReference{controllerRef1}
 	pod1.ResourceVersion = "1"
 	pod2 := pod1
 	pod2.Labels = labelMap2
 	pod2.ResourceVersion = "2"
 	manager.updatePod(&pod1, &pod2)
-	expected := sets.NewString(testRSSpec1.Name, testRSSpec2.Name)
+	expected := sets.NewString(testRSSpec1.Name)
 	for _, name := range expected.List() {
 		t.Logf("Expecting update for %+v", name)
 		select {
@@ -674,17 +680,20 @@ func TestUpdatePods(t *testing.T) {
 				t.Errorf("Expected keys %#v got %v", expected, got)
 			}
 		case <-time.After(wait.ForeverTestTimeout):
-			t.Errorf("Expected update notifications for replica sets within 100ms each")
+			t.Errorf("Expected update notifications for replica sets")
 		}
 	}

-	// case 2: pod1 in the podLister has labels matching testRSSpec1. We update
-	// its labels to match no replica set. We expect to receive a sync request
-	// for testRSSpec1.
-	pod2.Labels = make(map[string]string)
+	// case 2: Remove ControllerRef (orphan). Expect to sync label-matching RS.
+	pod1 = newPodList(informers.Core().V1().Pods().Informer().GetIndexer(), 1, v1.PodRunning, labelMap1, testRSSpec1, "pod").Items[0]
+	pod1.ResourceVersion = "1"
+	pod1.Labels = labelMap2
+	pod1.OwnerReferences = []metav1.OwnerReference{controllerRef2}
+	pod2 = pod1
+	pod2.OwnerReferences = nil
 	pod2.ResourceVersion = "2"
 	manager.updatePod(&pod1, &pod2)
-	expected = sets.NewString(testRSSpec1.Name)
+	expected = sets.NewString(testRSSpec2.Name)
 	for _, name := range expected.List() {
 		t.Logf("Expecting update for %+v", name)
 		select {
@@ -693,7 +702,52 @@ func TestUpdatePods(t *testing.T) {
 				t.Errorf("Expected keys %#v got %v", expected, got)
 			}
 		case <-time.After(wait.ForeverTestTimeout):
-			t.Errorf("Expected update notifications for replica sets within 100ms each")
+			t.Errorf("Expected update notifications for replica sets")
+		}
+	}
+
+	// case 2: Remove ControllerRef (orphan). Expect to sync both former owner and
+	// any label-matching RS.
+	pod1 = newPodList(informers.Core().V1().Pods().Informer().GetIndexer(), 1, v1.PodRunning, labelMap1, testRSSpec1, "pod").Items[0]
+	pod1.ResourceVersion = "1"
+	pod1.Labels = labelMap2
+	pod1.OwnerReferences = []metav1.OwnerReference{controllerRef1}
+	pod2 = pod1
+	pod2.OwnerReferences = nil
+	pod2.ResourceVersion = "2"
+	manager.updatePod(&pod1, &pod2)
+	expected = sets.NewString(testRSSpec1.Name, testRSSpec2.Name)
+	for _, name := range expected.List() {
+		t.Logf("Expecting update for %+v", name)
+		select {
+		case got := <-received:
+			if !expected.Has(got) {
+				t.Errorf("Expected keys %#v got %v", expected, got)
+			}
+		case <-time.After(wait.ForeverTestTimeout):
+			t.Errorf("Expected update notifications for replica sets")
+		}
+	}
+
+	// case 4: Keep ControllerRef, change labels. Expect to sync owning RS.
+	pod1 = newPodList(informers.Core().V1().Pods().Informer().GetIndexer(), 1, v1.PodRunning, labelMap1, testRSSpec1, "pod").Items[0]
+	pod1.ResourceVersion = "1"
+	pod1.Labels = labelMap1
+	pod1.OwnerReferences = []metav1.OwnerReference{controllerRef2}
+	pod2 = pod1
+	pod2.Labels = labelMap2
+	pod2.ResourceVersion = "2"
+	manager.updatePod(&pod1, &pod2)
+	expected = sets.NewString(testRSSpec2.Name)
+	for _, name := range expected.List() {
+		t.Logf("Expecting update for %+v", name)
+		select {
+		case got := <-received:
+			if !expected.Has(got) {
+				t.Errorf("Expected keys %#v got %v", expected, got)
+			}
+		case <-time.After(wait.ForeverTestTimeout):
+			t.Errorf("Expected update notifications for replica sets")
 		}
 	}
 }
@@ -711,7 +765,7 @@ func TestControllerUpdateRequeue(t *testing.T) {
 	stopCh := make(chan struct{})
 	defer close(stopCh)
 	client := clientset.NewForConfigOrDie(&restclient.Config{Host: testServer.URL, ContentConfig: restclient.ContentConfig{GroupVersion: &api.Registry.GroupOrDie(v1.GroupName).GroupVersion}})
-	manager, informers := testNewReplicaSetControllerFromClient(client, stopCh, BurstReplicas, 0)
+	manager, informers := testNewReplicaSetControllerFromClient(client, stopCh, BurstReplicas)

 	labelMap := map[string]string{"foo": "bar"}
 	rs := newReplicaSet(1, labelMap)
@@ -782,7 +836,7 @@ func doTestControllerBurstReplicas(t *testing.T, burstReplicas, numReplicas int)
 	fakePodControl := controller.FakePodControl{}
 	stopCh := make(chan struct{})
 	defer close(stopCh)
-	manager, informers := testNewReplicaSetControllerFromClient(client, stopCh, burstReplicas, 0)
+	manager, informers := testNewReplicaSetControllerFromClient(client, stopCh, burstReplicas)
 	manager.podControl = &fakePodControl

 	labelMap := map[string]string{"foo": "bar"}
@@ -845,6 +899,7 @@ func doTestControllerBurstReplicas(t *testing.T, burstReplicas, numReplicas int)
 				// the rs is waiting for.
 				expectedDels := manager.expectations.GetUIDs(getKey(rsSpec, t))
 				podsToDelete := []*v1.Pod{}
+				isController := true
 				for _, key := range expectedDels.List() {
 					nsName := strings.Split(key, "/")
 					podsToDelete = append(podsToDelete, &v1.Pod{
@@ -852,6 +907,9 @@ func doTestControllerBurstReplicas(t *testing.T, burstReplicas, numReplicas int)
 							Name:      nsName[1],
 							Namespace: nsName[0],
 							Labels:    rsSpec.Spec.Selector.MatchLabels,
+							OwnerReferences: []metav1.OwnerReference{
+								{UID: rsSpec.UID, APIVersion: "v1", Kind: "ReplicaSet", Name: rsSpec.Name, Controller: &isController},
+							},
 						},
 					})
 				}
@@ -888,11 +946,15 @@ func doTestControllerBurstReplicas(t *testing.T, burstReplicas, numReplicas int)
 					t.Fatalf("Waiting on unexpected number of deletes.")
 				}
 				nsName := strings.Split(expectedDel.List()[0], "/")
+				isController := true
 				lastPod := &v1.Pod{
 					ObjectMeta: metav1.ObjectMeta{
 						Name:      nsName[1],
 						Namespace: nsName[0],
 						Labels:    rsSpec.Spec.Selector.MatchLabels,
+						OwnerReferences: []metav1.OwnerReference{
+							{UID: rsSpec.UID, APIVersion: "v1", Kind: "ReplicaSet", Name: rsSpec.Name, Controller: &isController},
+						},
 					},
 				}
 				informers.Core().V1().Pods().Informer().GetIndexer().Delete(lastPod)
@@ -935,7 +997,7 @@ func TestRSSyncExpectations(t *testing.T) {
 	fakePodControl := controller.FakePodControl{}
 	stopCh := make(chan struct{})
 	defer close(stopCh)
-	manager, informers := testNewReplicaSetControllerFromClient(client, stopCh, 2, 0)
+	manager, informers := testNewReplicaSetControllerFromClient(client, stopCh, 2)
 	manager.podControl = &fakePodControl

 	labelMap := map[string]string{"foo": "bar"}
@@ -961,7 +1023,7 @@ func TestDeleteControllerAndExpectations(t *testing.T) {
 	client := clientset.NewForConfigOrDie(&restclient.Config{Host: "", ContentConfig: restclient.ContentConfig{GroupVersion: &api.Registry.GroupOrDie(v1.GroupName).GroupVersion}})
 	stopCh := make(chan struct{})
 	defer close(stopCh)
-	manager, informers := testNewReplicaSetControllerFromClient(client, stopCh, 10, 0)
+	manager, informers := testNewReplicaSetControllerFromClient(client, stopCh, 10)

 	rs := newReplicaSet(1, map[string]string{"foo": "bar"})
 	informers.Extensions().V1beta1().ReplicaSets().Informer().GetIndexer().Add(rs)
@@ -1015,34 +1077,42 @@ func TestOverlappingRSs(t *testing.T) {
 	client := clientset.NewForConfigOrDie(&restclient.Config{Host: "", ContentConfig: restclient.ContentConfig{GroupVersion: &api.Registry.GroupOrDie(v1.GroupName).GroupVersion}})
 	labelMap := map[string]string{"foo": "bar"}

-	for i := 0; i < 5; i++ {
-		func() {
-			stopCh := make(chan struct{})
-			defer close(stopCh)
-			manager, informers := testNewReplicaSetControllerFromClient(client, stopCh, 10, 0)
+	stopCh := make(chan struct{})
+	defer close(stopCh)
+	manager, informers := testNewReplicaSetControllerFromClient(client, stopCh, 10)

-			// Create 10 ReplicaSets, shuffled them randomly and insert them into the ReplicaSet controller's store
-			var controllers []*extensions.ReplicaSet
-			for j := 1; j < 10; j++ {
-				rsSpec := newReplicaSet(1, labelMap)
-				rsSpec.CreationTimestamp = metav1.Date(2014, time.December, j, 0, 0, 0, 0, time.Local)
-				rsSpec.Name = string(uuid.NewUUID())
-				controllers = append(controllers, rsSpec)
-			}
-			shuffledControllers := shuffle(controllers)
-			for j := range shuffledControllers {
-				informers.Extensions().V1beta1().ReplicaSets().Informer().GetIndexer().Add(shuffledControllers[j])
-			}
-			// Add a pod and make sure only the oldest ReplicaSet is synced
-			pods := newPodList(nil, 1, v1.PodPending, labelMap, controllers[0], "pod")
-			rsKey := getKey(controllers[0], t)
+	// Create 10 ReplicaSets, shuffled them randomly and insert them into the
+	// ReplicaSet controller's store.
+	// All use the same CreationTimestamp since ControllerRef should be able
+	// to handle that.
+	timestamp := metav1.Date(2014, time.December, 0, 0, 0, 0, 0, time.Local)
+	var controllers []*extensions.ReplicaSet
+	for j := 1; j < 10; j++ {
+		rsSpec := newReplicaSet(1, labelMap)
+		rsSpec.CreationTimestamp = timestamp
+		rsSpec.Name = fmt.Sprintf("rs%d", j)
+		controllers = append(controllers, rsSpec)
+	}
+	shuffledControllers := shuffle(controllers)
+	for j := range shuffledControllers {
+		informers.Extensions().V1beta1().ReplicaSets().Informer().GetIndexer().Add(shuffledControllers[j])
+	}
+	// Add a pod with a ControllerRef and make sure only the corresponding
+	// ReplicaSet is synced. Pick a RS in the middle since the old code used to
+	// sort by name if all timestamps were equal.
+	rs := controllers[3]
+	pods := newPodList(nil, 1, v1.PodPending, labelMap, rs, "pod")
+	pod := &pods.Items[0]
+	isController := true
+	pod.OwnerReferences = []metav1.OwnerReference{
+		{UID: rs.UID, APIVersion: "v1", Kind: "ReplicaSet", Name: rs.Name, Controller: &isController},
+	}
+	rsKey := getKey(rs, t)

-			manager.addPod(&pods.Items[0])
-			queueRS, _ := manager.queue.Get()
-			if queueRS != rsKey {
-				t.Fatalf("Expected to find key %v in queue, found %v", rsKey, queueRS)
-			}
-		}()
+	manager.addPod(pod)
+	queueRS, _ := manager.queue.Get()
+	if queueRS != rsKey {
+		t.Fatalf("Expected to find key %v in queue, found %v", rsKey, queueRS)
 	}
 }

@@ -1051,7 +1121,7 @@ func TestDeletionTimestamp(t *testing.T) {
 	labelMap := map[string]string{"foo": "bar"}
 	stopCh := make(chan struct{})
 	defer close(stopCh)
-	manager, informers := testNewReplicaSetControllerFromClient(c, stopCh, 10, 0)
+	manager, informers := testNewReplicaSetControllerFromClient(c, stopCh, 10)

 	rs := newReplicaSet(1, labelMap)
 	informers.Extensions().V1beta1().ReplicaSets().Informer().GetIndexer().Add(rs)
@@ -1098,11 +1168,15 @@ 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.
+	isController := true
 	secondPod := &v1.Pod{
 		ObjectMeta: metav1.ObjectMeta{
 			Namespace: pod.Namespace,
 			Name:      "secondPod",
 			Labels:    pod.Labels,
+			OwnerReferences: []metav1.OwnerReference{
+				{UID: rs.UID, APIVersion: "v1", Kind: "ReplicaSet", Name: rs.Name, Controller: &isController},
+			},
 		},
 	}
 	manager.expectations.ExpectDeletions(rsKey, []string{controller.PodKey(secondPod)})
@@ -1142,7 +1216,7 @@ func TestDeletionTimestamp(t *testing.T) {
 func setupManagerWithGCEnabled(stopCh chan struct{}, objs ...runtime.Object) (manager *ReplicaSetController, fakePodControl *controller.FakePodControl, informers informers.SharedInformerFactory) {
 	c := fakeclientset.NewSimpleClientset(objs...)
 	fakePodControl = &controller.FakePodControl{}
-	manager, informers = testNewReplicaSetControllerFromClient(c, stopCh, BurstReplicas, 0)
+	manager, informers = testNewReplicaSetControllerFromClient(c, stopCh, BurstReplicas)

 	manager.podControl = fakePodControl
 	return manager, fakePodControl, informers
@@ -1372,7 +1446,7 @@ func TestReadyReplicas(t *testing.T) {
 	client := clientset.NewForConfigOrDie(&restclient.Config{Host: testServer.URL, ContentConfig: restclient.ContentConfig{GroupVersion: &api.Registry.GroupOrDie(v1.GroupName).GroupVersion}})
 	stopCh := make(chan struct{})
 	defer close(stopCh)
-	manager, informers := testNewReplicaSetControllerFromClient(client, stopCh, BurstReplicas, 0)
+	manager, informers := testNewReplicaSetControllerFromClient(client, stopCh, BurstReplicas)

 	// Status.Replica should update to match number of pods in system, 1 new pod should be created.
 	labelMap := map[string]string{"foo": "bar"}
@@ -1414,7 +1488,7 @@ func TestAvailableReplicas(t *testing.T) {
 	client := clientset.NewForConfigOrDie(&restclient.Config{Host: testServer.URL, ContentConfig: restclient.ContentConfig{GroupVersion: &api.Registry.GroupOrDie(v1.GroupName).GroupVersion}})
 	stopCh := make(chan struct{})
 	defer close(stopCh)
-	manager, informers := testNewReplicaSetControllerFromClient(client, stopCh, BurstReplicas, 0)
+	manager, informers := testNewReplicaSetControllerFromClient(client, stopCh, BurstReplicas)

 	// Status.Replica should update to match number of pods in system, 1 new pod should be created.
 	labelMap := map[string]string{"foo": "bar"}