add occasional polling to reflector

duda · Feb 28, 2015 · 554b1c8 · 554b1c8
1 parent 156c505
commit 554b1c8
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Showing 7 changed files with 110 additions and 47 deletions.
diff --git a/pkg/client/cache/reflector.go b/pkg/client/cache/reflector.go
@@ -49,18 +49,23 @@ type Reflector struct {
 	listerWatcher ListerWatcher
 	// period controls timing between one watch ending and
 	// the beginning of the next one.
-	period time.Duration
+	period       time.Duration
+	resyncPeriod time.Duration
 }
 
 // NewReflector creates a new Reflector object which will keep the given store up to
 // date with the server's contents for the given resource. Reflector promises to
 // only put things in the store that have the type of expectedType.
-func NewReflector(lw ListerWatcher, expectedType interface{}, store Store) *Reflector {
+// If resyncPeriod is non-zero, then lists will be executed after every resyncPeriod,
+// so that you can use reflectors to periodically process everything as well as
+// incrementally processing the things that change.
+func NewReflector(lw ListerWatcher, expectedType interface{}, store Store, resyncPeriod time.Duration) *Reflector {
 	r := &Reflector{
 		listerWatcher: lw,
 		store:         store,
 		expectedType:  reflect.TypeOf(expectedType),
 		period:        time.Second,
+		resyncPeriod:  resyncPeriod,
 	}
 	return r
 }
@@ -77,8 +82,25 @@ func (r *Reflector) RunUntil(stopCh <-chan struct{}) {
 	go util.Until(func() { r.listAndWatch() }, r.period, stopCh)
 }
 
+var (
+	// nothing will ever be sent down this channel
+	neverExitWatch <-chan time.Time = make(chan time.Time)
+
+	// Used to indicate that watching stopped so that a resync could happen.
+	errorResyncRequested = errors.New("resync channel fired")
+)
+
+// resyncChan returns a channel which will receive something when a resync is required.
+func (r *Reflector) resyncChan() <-chan time.Time {
+	if r.resyncPeriod == 0 {
+		return neverExitWatch
+	}
+	return time.After(r.resyncPeriod)
+}
+
 func (r *Reflector) listAndWatch() {
 	var resourceVersion string
+	exitWatch := r.resyncChan()
 
 	list, err := r.listerWatcher.List()
 	if err != nil {
@@ -114,8 +136,10 @@ func (r *Reflector) listAndWatch() {
 			}
 			return
 		}
-		if err := r.watchHandler(w, &resourceVersion); err != nil {
-			glog.Errorf("watch of %v ended with error: %v", r.expectedType, err)
+		if err := r.watchHandler(w, &resourceVersion, exitWatch); err != nil {
+			if err != errorResyncRequested {
+				glog.Errorf("watch of %v ended with error: %v", r.expectedType, err)
+			}
 			return
 		}
 	}
@@ -132,41 +156,47 @@ func (r *Reflector) syncWith(items []runtime.Object) error {
 }
 
 // watchHandler watches w and keeps *resourceVersion up to date.
-func (r *Reflector) watchHandler(w watch.Interface, resourceVersion *string) error {
+func (r *Reflector) watchHandler(w watch.Interface, resourceVersion *string, exitWatch <-chan time.Time) error {
 	start := time.Now()
 	eventCount := 0
+loop:
 	for {
-		event, ok := <-w.ResultChan()
-		if !ok {
-			break
-		}
-		if event.Type == watch.Error {
-			return apierrs.FromObject(event.Object)
-		}
-		if e, a := r.expectedType, reflect.TypeOf(event.Object); e != a {
-			glog.Errorf("expected type %v, but watch event object had type %v", e, a)
-			continue
-		}
-		meta, err := meta.Accessor(event.Object)
-		if err != nil {
-			glog.Errorf("unable to understand watch event %#v", event)
-			continue
-		}
-		switch event.Type {
-		case watch.Added:
-			r.store.Add(event.Object)
-		case watch.Modified:
-			r.store.Update(event.Object)
-		case watch.Deleted:
-			// TODO: Will any consumers need access to the "last known
-			// state", which is passed in event.Object? If so, may need
-			// to change this.
-			r.store.Delete(event.Object)
-		default:
-			glog.Errorf("unable to understand watch event %#v", event)
+		select {
+		case <-exitWatch:
+			w.Stop()
+			return errorResyncRequested
+		case event, ok := <-w.ResultChan():
+			if !ok {
+				break loop
+			}
+			if event.Type == watch.Error {
+				return apierrs.FromObject(event.Object)
+			}
+			if e, a := r.expectedType, reflect.TypeOf(event.Object); e != a {
+				glog.Errorf("expected type %v, but watch event object had type %v", e, a)
+				continue
+			}
+			meta, err := meta.Accessor(event.Object)
+			if err != nil {
+				glog.Errorf("unable to understand watch event %#v", event)
+				continue
+			}
+			switch event.Type {
+			case watch.Added:
+				r.store.Add(event.Object)
+			case watch.Modified:
+				r.store.Update(event.Object)
+			case watch.Deleted:
+				// TODO: Will any consumers need access to the "last known
+				// state", which is passed in event.Object? If so, may need
+				// to change this.
+				r.store.Delete(event.Object)
+			default:
+				glog.Errorf("unable to understand watch event %#v", event)
+			}
+			*resourceVersion = meta.ResourceVersion()
+			eventCount++
 		}
-		*resourceVersion = meta.ResourceVersion()
-		eventCount++
 	}
 
 	watchDuration := time.Now().Sub(start)

diff --git a/pkg/client/cache/reflector_test.go b/pkg/client/cache/reflector_test.go
@@ -20,6 +20,7 @@ import (
 	"fmt"
 	"strconv"
 	"testing"
+	"time"
 
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/runtime"
@@ -36,23 +37,35 @@ func (t *testLW) Watch(resourceVersion string) (watch.Interface, error) {
 	return t.WatchFunc(resourceVersion)
 }
 
+func TestReflector_resyncChan(t *testing.T) {
+	s := NewStore(MetaNamespaceKeyFunc)
+	g := NewReflector(&testLW{}, &api.Pod{}, s, time.Millisecond)
+	a, b := g.resyncChan(), time.After(100*time.Millisecond)
+	select {
+	case <-a:
+		t.Logf("got timeout as expected")
+	case <-b:
+		t.Errorf("resyncChan() is at least 99 milliseconds late??")
+	}
+}
+
 func TestReflector_watchHandlerError(t *testing.T) {
 	s := NewStore(MetaNamespaceKeyFunc)
-	g := NewReflector(&testLW{}, &api.Pod{}, s)
+	g := NewReflector(&testLW{}, &api.Pod{}, s, 0)
 	fw := watch.NewFake()
 	go func() {
 		fw.Stop()
 	}()
 	var resumeRV string
-	err := g.watchHandler(fw, &resumeRV)
+	err := g.watchHandler(fw, &resumeRV, neverExitWatch)
 	if err == nil {
 		t.Errorf("unexpected non-error")
 	}
 }
 
 func TestReflector_watchHandler(t *testing.T) {
 	s := NewStore(MetaNamespaceKeyFunc)
-	g := NewReflector(&testLW{}, &api.Pod{}, s)
+	g := NewReflector(&testLW{}, &api.Pod{}, s, 0)
 	fw := watch.NewFake()
 	s.Add(&api.Pod{ObjectMeta: api.ObjectMeta{Name: "foo"}})
 	s.Add(&api.Pod{ObjectMeta: api.ObjectMeta{Name: "bar"}})
@@ -64,7 +77,7 @@ func TestReflector_watchHandler(t *testing.T) {
 		fw.Stop()
 	}()
 	var resumeRV string
-	err := g.watchHandler(fw, &resumeRV)
+	err := g.watchHandler(fw, &resumeRV, neverExitWatch)
 	if err != nil {
 		t.Errorf("unexpected error %v", err)
 	}
@@ -101,6 +114,19 @@ func TestReflector_watchHandler(t *testing.T) {
 	}
 }
 
+func TestReflector_watchHandlerTimeout(t *testing.T) {
+	s := NewStore(MetaNamespaceKeyFunc)
+	g := NewReflector(&testLW{}, &api.Pod{}, s, 0)
+	fw := watch.NewFake()
+	var resumeRV string
+	exit := make(chan time.Time, 1)
+	exit <- time.Now()
+	err := g.watchHandler(fw, &resumeRV, exit)
+	if err != errorResyncRequested {
+		t.Errorf("expected timeout error, but got %q", err)
+	}
+}
+
 func TestReflector_listAndWatch(t *testing.T) {
 	createdFakes := make(chan *watch.FakeWatcher)
 
@@ -125,7 +151,7 @@ func TestReflector_listAndWatch(t *testing.T) {
 		},
 	}
 	s := NewFIFO(MetaNamespaceKeyFunc)
-	r := NewReflector(lw, &api.Pod{}, s)
+	r := NewReflector(lw, &api.Pod{}, s, 0)
 	go r.listAndWatch()
 
 	ids := []string{"foo", "bar", "baz", "qux", "zoo"}
@@ -242,7 +268,7 @@ func TestReflector_listAndWatchWithErrors(t *testing.T) {
 				return item.list, item.listErr
 			},
 		}
-		r := NewReflector(lw, &api.Pod{}, s)
+		r := NewReflector(lw, &api.Pod{}, s, 0)
 		r.listAndWatch()
 	}
 }
diff --git a/pkg/kubelet/config/apiserver.go b/pkg/kubelet/config/apiserver.go
@@ -49,7 +49,7 @@ func newSourceApiserverFromLW(lw cache.ListerWatcher, updates chan<- interface{}
 		}
 		updates <- kubelet.PodUpdate{bpods, kubelet.SET, kubelet.ApiserverSource}
 	}
-	cache.NewReflector(lw, &api.Pod{}, cache.NewUndeltaStore(send, cache.MetaNamespaceKeyFunc)).Run()
+	cache.NewReflector(lw, &api.Pod{}, cache.NewUndeltaStore(send, cache.MetaNamespaceKeyFunc), 0).Run()
 }
 
 func getHostFieldLabel(apiVersion string) string {

diff --git a/pkg/kubelet/kubelet.go b/pkg/kubelet/kubelet.go
@@ -102,7 +102,12 @@ func NewMainKubelet(
 
 	serviceStore := cache.NewStore(cache.MetaNamespaceKeyFunc)
 	if kubeClient != nil {
-		cache.NewReflector(cache.NewListWatchFromClient(kubeClient, "services", api.NamespaceAll, labels.Everything()), &api.Service{}, serviceStore).Run()
+		cache.NewReflector(
+			cache.NewListWatchFromClient(kubeClient, "services", api.NamespaceAll, labels.Everything()),
+			&api.Service{},
+			serviceStore,
+			0,
+		).Run()
 	}
 	serviceLister := &cache.StoreToServiceLister{serviceStore}
 

diff --git a/plugin/pkg/admission/namespace/autoprovision/admission.go b/plugin/pkg/admission/namespace/autoprovision/admission.go
@@ -90,6 +90,7 @@ func NewProvision(c client.Interface) admission.Interface {
 		},
 		&api.Namespace{},
 		store,
+		0,
 	)
 	reflector.Run()
 	return &provision{

diff --git a/plugin/pkg/admission/namespace/exists/admission.go b/plugin/pkg/admission/namespace/exists/admission.go
@@ -94,6 +94,7 @@ func NewExists(c client.Interface) admission.Interface {
 		},
 		&api.Namespace{},
 		store,
+		0,
 	)
 	reflector.Run()
 	return &exists{

diff --git a/plugin/pkg/scheduler/factory/factory.go b/plugin/pkg/scheduler/factory/factory.go
@@ -94,26 +94,26 @@ func (f *ConfigFactory) CreateFromKeys(predicateKeys, priorityKeys util.StringSe
 	}
 
 	// Watch and queue pods that need scheduling.
-	cache.NewReflector(f.createUnassignedPodLW(), &api.Pod{}, f.PodQueue).Run()
+	cache.NewReflector(f.createUnassignedPodLW(), &api.Pod{}, f.PodQueue, 0).Run()
 
 	// Watch and cache all running pods. Scheduler needs to find all pods
 	// so it knows where it's safe to place a pod. Cache this locally.
-	cache.NewReflector(f.createAssignedPodLW(), &api.Pod{}, f.PodLister.Store).Run()
+	cache.NewReflector(f.createAssignedPodLW(), &api.Pod{}, f.PodLister.Store, 0).Run()
 
 	// Watch minions.
 	// Minions may be listed frequently, so provide a local up-to-date cache.
 	if false {
 		// Disable this code until minions support watches. Note when this code is enabled,
 		// we need to make sure minion ListWatcher has proper FieldSelector.
-		cache.NewReflector(f.createMinionLW(), &api.Node{}, f.MinionLister.Store).Run()
+		cache.NewReflector(f.createMinionLW(), &api.Node{}, f.MinionLister.Store, 0).Run()
 	} else {
 		cache.NewPoller(f.pollMinions, 10*time.Second, f.MinionLister.Store).Run()
 	}
 
 	// Watch and cache all service objects. Scheduler needs to find all pods
 	// created by the same service, so that it can spread them correctly.
 	// Cache this locally.
-	cache.NewReflector(f.createServiceLW(), &api.Service{}, f.ServiceLister.Store).Run()
+	cache.NewReflector(f.createServiceLW(), &api.Service{}, f.ServiceLister.Store, 0).Run()
 
 	r := rand.New(rand.NewSource(time.Now().UnixNano()))
-Original file line number
+Diff line change
@@ Expand Up / @@ -90,6 +90,7 @@ func NewProvision(c client.Interface) admission.Interface { @@
     		},
     		&api.Namespace{},
     		store,
+,
     	)
     	reflector.Run()
     	return &provision{
@@ Expand Down @@