Split cacheWatcher into its own file

This commit is contained in:
Wojciech Tyczyński 2023-02-24 11:59:01 +01:00
parent 5961d8ce1b
commit a537049110
4 changed files with 785 additions and 719 deletions

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/*
Copyright 2023 The Kubernetes Authors.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package cacher
import (
"context"
"fmt"
"time"
"k8s.io/apimachinery/pkg/runtime"
"k8s.io/apimachinery/pkg/runtime/schema"
utilruntime "k8s.io/apimachinery/pkg/util/runtime"
"k8s.io/apimachinery/pkg/watch"
"k8s.io/apiserver/pkg/storage"
"k8s.io/apiserver/pkg/storage/cacher/metrics"
utilflowcontrol "k8s.io/apiserver/pkg/util/flowcontrol"
"k8s.io/klog/v2"
)
// cacheWatcher implements watch.Interface
// this is not thread-safe
type cacheWatcher struct {
input chan *watchCacheEvent
result chan watch.Event
done chan struct{}
filter filterWithAttrsFunc
stopped bool
forget func(bool)
versioner storage.Versioner
// The watcher will be closed by server after the deadline,
// save it here to send bookmark events before that.
deadline time.Time
allowWatchBookmarks bool
groupResource schema.GroupResource
// human readable identifier that helps assigning cacheWatcher
// instance with request
identifier string
// drainInputBuffer indicates whether we should delay closing this watcher
// and send all event in the input buffer.
drainInputBuffer bool
}
func newCacheWatcher(
chanSize int,
filter filterWithAttrsFunc,
forget func(bool),
versioner storage.Versioner,
deadline time.Time,
allowWatchBookmarks bool,
groupResource schema.GroupResource,
identifier string,
) *cacheWatcher {
return &cacheWatcher{
input: make(chan *watchCacheEvent, chanSize),
result: make(chan watch.Event, chanSize),
done: make(chan struct{}),
filter: filter,
stopped: false,
forget: forget,
versioner: versioner,
deadline: deadline,
allowWatchBookmarks: allowWatchBookmarks,
groupResource: groupResource,
identifier: identifier,
}
}
// Implements watch.Interface.
func (c *cacheWatcher) ResultChan() <-chan watch.Event {
return c.result
}
// Implements watch.Interface.
func (c *cacheWatcher) Stop() {
c.forget(false)
}
// we rely on the fact that stopLocked is actually protected by Cacher.Lock()
func (c *cacheWatcher) stopLocked() {
if !c.stopped {
c.stopped = true
// stop without draining the input channel was requested.
if !c.drainInputBuffer {
close(c.done)
}
close(c.input)
}
// Even if the watcher was already stopped, if it previously was
// using draining mode and it's not using it now we need to
// close the done channel now. Otherwise we could leak the
// processing goroutine if it will be trying to put more objects
// into result channel, the channel will be full and there will
// already be noone on the processing the events on the receiving end.
if !c.drainInputBuffer && !c.isDoneChannelClosedLocked() {
close(c.done)
}
}
func (c *cacheWatcher) nonblockingAdd(event *watchCacheEvent) bool {
select {
case c.input <- event:
return true
default:
return false
}
}
// Nil timer means that add will not block (if it can't send event immediately, it will break the watcher)
func (c *cacheWatcher) add(event *watchCacheEvent, timer *time.Timer) bool {
// Try to send the event immediately, without blocking.
if c.nonblockingAdd(event) {
return true
}
closeFunc := func() {
// This means that we couldn't send event to that watcher.
// Since we don't want to block on it infinitely,
// we simply terminate it.
klog.V(1).Infof("Forcing %v watcher close due to unresponsiveness: %v. len(c.input) = %v, len(c.result) = %v", c.groupResource.String(), c.identifier, len(c.input), len(c.result))
metrics.TerminatedWatchersCounter.WithLabelValues(c.groupResource.String()).Inc()
c.forget(false)
}
if timer == nil {
closeFunc()
return false
}
// OK, block sending, but only until timer fires.
select {
case c.input <- event:
return true
case <-timer.C:
closeFunc()
return false
}
}
func (c *cacheWatcher) nextBookmarkTime(now time.Time, bookmarkFrequency time.Duration) (time.Time, bool) {
// We try to send bookmarks:
//
// (a) right before the watcher timeout - for now we simply set it 2s before
// the deadline
//
// (b) roughly every minute
//
// (b) gives us periodicity if the watch breaks due to unexpected
// conditions, (a) ensures that on timeout the watcher is as close to
// now as possible - this covers 99% of cases.
heartbeatTime := now.Add(bookmarkFrequency)
if c.deadline.IsZero() {
// Timeout is set by our client libraries (e.g. reflector) as well as defaulted by
// apiserver if properly configured. So this shoudln't happen in practice.
return heartbeatTime, true
}
if pretimeoutTime := c.deadline.Add(-2 * time.Second); pretimeoutTime.Before(heartbeatTime) {
heartbeatTime = pretimeoutTime
}
if heartbeatTime.Before(now) {
return time.Time{}, false
}
return heartbeatTime, true
}
// setDrainInputBufferLocked if set to true indicates that we should delay closing this watcher
// until we send all events residing in the input buffer.
func (c *cacheWatcher) setDrainInputBufferLocked(drain bool) {
c.drainInputBuffer = drain
}
// isDoneChannelClosed checks if c.done channel is closed
func (c *cacheWatcher) isDoneChannelClosedLocked() bool {
select {
case <-c.done:
return true
default:
}
return false
}
func getMutableObject(object runtime.Object) runtime.Object {
if _, ok := object.(*cachingObject); ok {
// It is safe to return without deep-copy, because the underlying
// object will lazily perform deep-copy on the first try to change
// any of its fields.
return object
}
return object.DeepCopyObject()
}
func updateResourceVersion(object runtime.Object, versioner storage.Versioner, resourceVersion uint64) {
if err := versioner.UpdateObject(object, resourceVersion); err != nil {
utilruntime.HandleError(fmt.Errorf("failure to version api object (%d) %#v: %v", resourceVersion, object, err))
}
}
func (c *cacheWatcher) convertToWatchEvent(event *watchCacheEvent) *watch.Event {
if event.Type == watch.Bookmark {
return &watch.Event{Type: watch.Bookmark, Object: event.Object.DeepCopyObject()}
}
curObjPasses := event.Type != watch.Deleted && c.filter(event.Key, event.ObjLabels, event.ObjFields)
oldObjPasses := false
if event.PrevObject != nil {
oldObjPasses = c.filter(event.Key, event.PrevObjLabels, event.PrevObjFields)
}
if !curObjPasses && !oldObjPasses {
// Watcher is not interested in that object.
return nil
}
switch {
case curObjPasses && !oldObjPasses:
return &watch.Event{Type: watch.Added, Object: getMutableObject(event.Object)}
case curObjPasses && oldObjPasses:
return &watch.Event{Type: watch.Modified, Object: getMutableObject(event.Object)}
case !curObjPasses && oldObjPasses:
// return a delete event with the previous object content, but with the event's resource version
oldObj := getMutableObject(event.PrevObject)
// We know that if oldObj is cachingObject (which can only be set via
// setCachingObjects), its resourceVersion is already set correctly and
// we don't need to update it. However, since cachingObject efficiently
// handles noop updates, we avoid this microoptimization here.
updateResourceVersion(oldObj, c.versioner, event.ResourceVersion)
return &watch.Event{Type: watch.Deleted, Object: oldObj}
}
return nil
}
// NOTE: sendWatchCacheEvent is assumed to not modify <event> !!!
func (c *cacheWatcher) sendWatchCacheEvent(event *watchCacheEvent) {
watchEvent := c.convertToWatchEvent(event)
if watchEvent == nil {
// Watcher is not interested in that object.
return
}
// We need to ensure that if we put event X to the c.result, all
// previous events were already put into it before, no matter whether
// c.done is close or not.
// Thus we cannot simply select from c.done and c.result and this
// would give us non-determinism.
// At the same time, we don't want to block infinitely on putting
// to c.result, when c.done is already closed.
//
// This ensures that with c.done already close, we at most once go
// into the next select after this. With that, no matter which
// statement we choose there, we will deliver only consecutive
// events.
select {
case <-c.done:
return
default:
}
select {
case c.result <- *watchEvent:
case <-c.done:
}
}
func (c *cacheWatcher) processInterval(ctx context.Context, cacheInterval *watchCacheInterval, resourceVersion uint64) {
defer utilruntime.HandleCrash()
defer close(c.result)
defer c.Stop()
// Check how long we are processing initEvents.
// As long as these are not processed, we are not processing
// any incoming events, so if it takes long, we may actually
// block all watchers for some time.
// TODO: From the logs it seems that there happens processing
// times even up to 1s which is very long. However, this doesn't
// depend that much on the number of initEvents. E.g. from the
// 2000-node Kubemark run we have logs like this, e.g.:
// ... processing 13862 initEvents took 66.808689ms
// ... processing 14040 initEvents took 993.532539ms
// We should understand what is blocking us in those cases (e.g.
// is it lack of CPU, network, or sth else) and potentially
// consider increase size of result buffer in those cases.
const initProcessThreshold = 500 * time.Millisecond
startTime := time.Now()
initEventCount := 0
for {
event, err := cacheInterval.Next()
if err != nil {
// An error indicates that the cache interval
// has been invalidated and can no longer serve
// events.
//
// Initially we considered sending an "out-of-history"
// Error event in this case, but because historically
// such events weren't sent out of the watchCache, we
// decided not to. This is still ok, because on watch
// closure, the watcher will try to re-instantiate the
// watch and then will get an explicit "out-of-history"
// window. There is potential for optimization, but for
// now, in order to be on the safe side and not break
// custom clients, the cost of it is something that we
// are fully accepting.
klog.Warningf("couldn't retrieve watch event to serve: %#v", err)
return
}
if event == nil {
break
}
c.sendWatchCacheEvent(event)
// With some events already sent, update resourceVersion so that
// events that were buffered and not yet processed won't be delivered
// to this watcher second time causing going back in time.
resourceVersion = event.ResourceVersion
initEventCount++
}
if initEventCount > 0 {
metrics.InitCounter.WithLabelValues(c.groupResource.String()).Add(float64(initEventCount))
}
processingTime := time.Since(startTime)
if processingTime > initProcessThreshold {
klog.V(2).Infof("processing %d initEvents of %s (%s) took %v", initEventCount, c.groupResource, c.identifier, processingTime)
}
c.process(ctx, resourceVersion)
}
func (c *cacheWatcher) process(ctx context.Context, resourceVersion uint64) {
// At this point we already start processing incoming watch events.
// However, the init event can still be processed because their serialization
// and sending to the client happens asynchrnously.
// TODO: As describe in the KEP, we would like to estimate that by delaying
// the initialization signal proportionally to the number of events to
// process, but we're leaving this to the tuning phase.
utilflowcontrol.WatchInitialized(ctx)
for {
select {
case event, ok := <-c.input:
if !ok {
return
}
// only send events newer than resourceVersion
if event.ResourceVersion > resourceVersion {
c.sendWatchCacheEvent(event)
}
case <-ctx.Done():
return
}
}
}

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/*
Copyright 2023 The Kubernetes Authors.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package cacher
import (
"context"
"fmt"
"reflect"
"sync"
"testing"
"time"
v1 "k8s.io/api/core/v1"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
"k8s.io/apimachinery/pkg/fields"
"k8s.io/apimachinery/pkg/labels"
"k8s.io/apimachinery/pkg/runtime/schema"
"k8s.io/apimachinery/pkg/util/diff"
"k8s.io/apimachinery/pkg/util/wait"
"k8s.io/apimachinery/pkg/watch"
"k8s.io/apiserver/pkg/storage"
testingclock "k8s.io/utils/clock/testing"
)
// verifies the cacheWatcher.process goroutine is properly cleaned up even if
// the writes to cacheWatcher.result channel is blocked.
func TestCacheWatcherCleanupNotBlockedByResult(t *testing.T) {
var lock sync.RWMutex
var w *cacheWatcher
count := 0
filter := func(string, labels.Set, fields.Set) bool { return true }
forget := func(drainWatcher bool) {
lock.Lock()
defer lock.Unlock()
count++
// forget() has to stop the watcher, as only stopping the watcher
// triggers stopping the process() goroutine which we are in the
// end waiting for in this test.
w.setDrainInputBufferLocked(drainWatcher)
w.stopLocked()
}
initEvents := []*watchCacheEvent{
{Object: &v1.Pod{}},
{Object: &v1.Pod{}},
}
// set the size of the buffer of w.result to 0, so that the writes to
// w.result is blocked.
w = newCacheWatcher(0, filter, forget, testVersioner{}, time.Now(), false, schema.GroupResource{Resource: "pods"}, "")
go w.processInterval(context.Background(), intervalFromEvents(initEvents), 0)
w.Stop()
if err := wait.PollImmediate(1*time.Second, 5*time.Second, func() (bool, error) {
lock.RLock()
defer lock.RUnlock()
return count == 2, nil
}); err != nil {
t.Fatalf("expected forget() to be called twice, because sendWatchCacheEvent should not be blocked by the result channel: %v", err)
}
}
func TestCacheWatcherHandlesFiltering(t *testing.T) {
filter := func(_ string, _ labels.Set, field fields.Set) bool {
return field["spec.nodeName"] == "host"
}
forget := func(bool) {}
testCases := []struct {
events []*watchCacheEvent
expected []watch.Event
}{
// properly handle starting with the filter, then being deleted, then re-added
{
events: []*watchCacheEvent{
{
Type: watch.Added,
Object: &v1.Pod{ObjectMeta: metav1.ObjectMeta{ResourceVersion: "1"}},
ObjFields: fields.Set{"spec.nodeName": "host"},
ResourceVersion: 1,
},
{
Type: watch.Modified,
PrevObject: &v1.Pod{ObjectMeta: metav1.ObjectMeta{ResourceVersion: "1"}},
PrevObjFields: fields.Set{"spec.nodeName": "host"},
Object: &v1.Pod{ObjectMeta: metav1.ObjectMeta{ResourceVersion: "2"}},
ObjFields: fields.Set{"spec.nodeName": ""},
ResourceVersion: 2,
},
{
Type: watch.Modified,
PrevObject: &v1.Pod{ObjectMeta: metav1.ObjectMeta{ResourceVersion: "2"}},
PrevObjFields: fields.Set{"spec.nodeName": ""},
Object: &v1.Pod{ObjectMeta: metav1.ObjectMeta{ResourceVersion: "3"}},
ObjFields: fields.Set{"spec.nodeName": "host"},
ResourceVersion: 3,
},
},
expected: []watch.Event{
{Type: watch.Added, Object: &v1.Pod{ObjectMeta: metav1.ObjectMeta{ResourceVersion: "1"}}},
{Type: watch.Deleted, Object: &v1.Pod{ObjectMeta: metav1.ObjectMeta{ResourceVersion: "2"}}},
{Type: watch.Added, Object: &v1.Pod{ObjectMeta: metav1.ObjectMeta{ResourceVersion: "3"}}},
},
},
// properly handle ignoring changes prior to the filter, then getting added, then deleted
{
events: []*watchCacheEvent{
{
Type: watch.Added,
Object: &v1.Pod{ObjectMeta: metav1.ObjectMeta{ResourceVersion: "1"}},
ObjFields: fields.Set{"spec.nodeName": ""},
ResourceVersion: 1,
},
{
Type: watch.Modified,
PrevObject: &v1.Pod{ObjectMeta: metav1.ObjectMeta{ResourceVersion: "1"}},
PrevObjFields: fields.Set{"spec.nodeName": ""},
Object: &v1.Pod{ObjectMeta: metav1.ObjectMeta{ResourceVersion: "2"}},
ObjFields: fields.Set{"spec.nodeName": ""},
ResourceVersion: 2,
},
{
Type: watch.Modified,
PrevObject: &v1.Pod{ObjectMeta: metav1.ObjectMeta{ResourceVersion: "2"}},
PrevObjFields: fields.Set{"spec.nodeName": ""},
Object: &v1.Pod{ObjectMeta: metav1.ObjectMeta{ResourceVersion: "3"}},
ObjFields: fields.Set{"spec.nodeName": "host"},
ResourceVersion: 3,
},
{
Type: watch.Modified,
PrevObject: &v1.Pod{ObjectMeta: metav1.ObjectMeta{ResourceVersion: "3"}},
PrevObjFields: fields.Set{"spec.nodeName": "host"},
Object: &v1.Pod{ObjectMeta: metav1.ObjectMeta{ResourceVersion: "4"}},
ObjFields: fields.Set{"spec.nodeName": "host"},
ResourceVersion: 4,
},
{
Type: watch.Modified,
PrevObject: &v1.Pod{ObjectMeta: metav1.ObjectMeta{ResourceVersion: "4"}},
PrevObjFields: fields.Set{"spec.nodeName": "host"},
Object: &v1.Pod{ObjectMeta: metav1.ObjectMeta{ResourceVersion: "5"}},
ObjFields: fields.Set{"spec.nodeName": ""},
ResourceVersion: 5,
},
{
Type: watch.Modified,
PrevObject: &v1.Pod{ObjectMeta: metav1.ObjectMeta{ResourceVersion: "5"}},
PrevObjFields: fields.Set{"spec.nodeName": ""},
Object: &v1.Pod{ObjectMeta: metav1.ObjectMeta{ResourceVersion: "6"}},
ObjFields: fields.Set{"spec.nodeName": ""},
ResourceVersion: 6,
},
},
expected: []watch.Event{
{Type: watch.Added, Object: &v1.Pod{ObjectMeta: metav1.ObjectMeta{ResourceVersion: "3"}}},
{Type: watch.Modified, Object: &v1.Pod{ObjectMeta: metav1.ObjectMeta{ResourceVersion: "4"}}},
{Type: watch.Deleted, Object: &v1.Pod{ObjectMeta: metav1.ObjectMeta{ResourceVersion: "5"}}},
},
},
}
TestCase:
for i, testCase := range testCases {
// set the size of the buffer of w.result to 0, so that the writes to
// w.result is blocked.
for j := range testCase.events {
testCase.events[j].ResourceVersion = uint64(j) + 1
}
w := newCacheWatcher(0, filter, forget, testVersioner{}, time.Now(), false, schema.GroupResource{Resource: "pods"}, "")
go w.processInterval(context.Background(), intervalFromEvents(testCase.events), 0)
ch := w.ResultChan()
for j, event := range testCase.expected {
e := <-ch
if !reflect.DeepEqual(event, e) {
t.Errorf("%d: unexpected event %d: %s", i, j, diff.ObjectReflectDiff(event, e))
break TestCase
}
}
select {
case obj, ok := <-ch:
t.Errorf("%d: unexpected excess event: %#v %t", i, obj, ok)
break TestCase
default:
}
w.setDrainInputBufferLocked(false)
w.stopLocked()
}
}
func TestCacheWatcherStoppedInAnotherGoroutine(t *testing.T) {
var w *cacheWatcher
done := make(chan struct{})
filter := func(string, labels.Set, fields.Set) bool { return true }
forget := func(drainWatcher bool) {
w.setDrainInputBufferLocked(drainWatcher)
w.stopLocked()
done <- struct{}{}
}
maxRetriesToProduceTheRaceCondition := 1000
// Simulating the timer is fired and stopped concurrently by set time
// timeout to zero and run the Stop goroutine concurrently.
// May sure that the watch will not be blocked on Stop.
for i := 0; i < maxRetriesToProduceTheRaceCondition; i++ {
w = newCacheWatcher(0, filter, forget, testVersioner{}, time.Now(), false, schema.GroupResource{Resource: "pods"}, "")
go w.Stop()
select {
case <-done:
case <-time.After(time.Second):
t.Fatal("stop is blocked when the timer is fired concurrently")
}
}
deadline := time.Now().Add(time.Hour)
// After that, verifies the cacheWatcher.process goroutine works correctly.
for i := 0; i < maxRetriesToProduceTheRaceCondition; i++ {
w = newCacheWatcher(2, filter, emptyFunc, testVersioner{}, deadline, false, schema.GroupResource{Resource: "pods"}, "")
w.input <- &watchCacheEvent{Object: &v1.Pod{}, ResourceVersion: uint64(i + 1)}
ctx, cancel := context.WithDeadline(context.Background(), deadline)
defer cancel()
go w.processInterval(ctx, intervalFromEvents(nil), 0)
select {
case <-w.ResultChan():
case <-time.After(time.Second):
t.Fatal("expected received a event on ResultChan")
}
w.setDrainInputBufferLocked(false)
w.stopLocked()
}
}
func TestCacheWatcherStoppedOnDestroy(t *testing.T) {
backingStorage := &dummyStorage{}
cacher, _, err := newTestCacher(backingStorage)
if err != nil {
t.Fatalf("Couldn't create cacher: %v", err)
}
defer cacher.Stop()
// Wait until cacher is initialized.
if err := cacher.ready.wait(); err != nil {
t.Fatalf("unexpected error waiting for the cache to be ready")
}
w, err := cacher.Watch(context.Background(), "pods/ns", storage.ListOptions{ResourceVersion: "0", Predicate: storage.Everything})
if err != nil {
t.Fatalf("Failed to create watch: %v", err)
}
watchClosed := make(chan struct{})
go func() {
defer close(watchClosed)
for event := range w.ResultChan() {
switch event.Type {
case watch.Added, watch.Modified, watch.Deleted:
// ok
default:
t.Errorf("unexpected event %#v", event)
}
}
}()
cacher.Stop()
select {
case <-watchClosed:
case <-time.After(wait.ForeverTestTimeout):
t.Errorf("timed out waiting for watch to close")
}
}
func TestTimeBucketWatchersBasic(t *testing.T) {
filter := func(_ string, _ labels.Set, _ fields.Set) bool {
return true
}
forget := func(bool) {}
newWatcher := func(deadline time.Time) *cacheWatcher {
return newCacheWatcher(0, filter, forget, testVersioner{}, deadline, true, schema.GroupResource{Resource: "pods"}, "")
}
clock := testingclock.NewFakeClock(time.Now())
watchers := newTimeBucketWatchers(clock, defaultBookmarkFrequency)
now := clock.Now()
watchers.addWatcher(newWatcher(now.Add(10 * time.Second)))
watchers.addWatcher(newWatcher(now.Add(20 * time.Second)))
watchers.addWatcher(newWatcher(now.Add(20 * time.Second)))
if len(watchers.watchersBuckets) != 2 {
t.Errorf("unexpected bucket size: %#v", watchers.watchersBuckets)
}
watchers0 := watchers.popExpiredWatchers()
if len(watchers0) != 0 {
t.Errorf("unexpected bucket size: %#v", watchers0)
}
clock.Step(10 * time.Second)
watchers1 := watchers.popExpiredWatchers()
if len(watchers1) != 1 || len(watchers1[0]) != 1 {
t.Errorf("unexpected bucket size: %v", watchers1)
}
watchers1 = watchers.popExpiredWatchers()
if len(watchers1) != 0 {
t.Errorf("unexpected bucket size: %#v", watchers1)
}
clock.Step(12 * time.Second)
watchers2 := watchers.popExpiredWatchers()
if len(watchers2) != 1 || len(watchers2[0]) != 2 {
t.Errorf("unexpected bucket size: %#v", watchers2)
}
}
func makeWatchCacheEvent(rv uint64) *watchCacheEvent {
return &watchCacheEvent{
Type: watch.Added,
Object: &v1.Pod{
ObjectMeta: metav1.ObjectMeta{
Name: fmt.Sprintf("pod-%d", rv),
ResourceVersion: fmt.Sprintf("%d", rv),
},
},
ResourceVersion: rv,
}
}
// TestCacheWatcherDraining verifies the cacheWatcher.process goroutine is properly cleaned up when draining was requested
func TestCacheWatcherDraining(t *testing.T) {
var lock sync.RWMutex
var w *cacheWatcher
count := 0
filter := func(string, labels.Set, fields.Set) bool { return true }
forget := func(drainWatcher bool) {
lock.Lock()
defer lock.Unlock()
count++
w.setDrainInputBufferLocked(drainWatcher)
w.stopLocked()
}
initEvents := []*watchCacheEvent{
makeWatchCacheEvent(5),
makeWatchCacheEvent(6),
}
w = newCacheWatcher(1, filter, forget, testVersioner{}, time.Now(), true, schema.GroupResource{Resource: "pods"}, "")
go w.processInterval(context.Background(), intervalFromEvents(initEvents), 1)
if !w.add(makeWatchCacheEvent(7), time.NewTimer(1*time.Second)) {
t.Fatal("failed adding an even to the watcher")
}
forget(true) // drain the watcher
eventCount := 0
for range w.ResultChan() {
eventCount++
}
if eventCount != 3 {
t.Errorf("Unexpected number of objects received: %d, expected: 3", eventCount)
}
if err := wait.PollImmediate(1*time.Second, 5*time.Second, func() (bool, error) {
lock.RLock()
defer lock.RUnlock()
return count == 2, nil
}); err != nil {
t.Fatalf("expected forget() to be called twice, because processInterval should call Stop(): %v", err)
}
}
// TestCacheWatcherDrainingRequestedButNotDrained verifies the cacheWatcher.process goroutine is properly cleaned up when draining was requested
// but the client never actually get any data
func TestCacheWatcherDrainingRequestedButNotDrained(t *testing.T) {
var lock sync.RWMutex
var w *cacheWatcher
count := 0
filter := func(string, labels.Set, fields.Set) bool { return true }
forget := func(drainWatcher bool) {
lock.Lock()
defer lock.Unlock()
count++
w.setDrainInputBufferLocked(drainWatcher)
w.stopLocked()
}
initEvents := []*watchCacheEvent{
makeWatchCacheEvent(5),
makeWatchCacheEvent(6),
}
w = newCacheWatcher(1, filter, forget, testVersioner{}, time.Now(), true, schema.GroupResource{Resource: "pods"}, "")
go w.processInterval(context.Background(), intervalFromEvents(initEvents), 1)
if !w.add(makeWatchCacheEvent(7), time.NewTimer(1*time.Second)) {
t.Fatal("failed adding an even to the watcher")
}
forget(true) // drain the watcher
w.Stop() // client disconnected, timeout expired or ctx was actually closed
if err := wait.PollImmediate(1*time.Second, 5*time.Second, func() (bool, error) {
lock.RLock()
defer lock.RUnlock()
return count == 3, nil
}); err != nil {
t.Fatalf("expected forget() to be called three times, because processInterval should call Stop(): %v", err)
}
}

View File

@ -34,7 +34,6 @@ import (
"k8s.io/apimachinery/pkg/labels"
"k8s.io/apimachinery/pkg/runtime"
"k8s.io/apimachinery/pkg/runtime/schema"
utilruntime "k8s.io/apimachinery/pkg/util/runtime"
"k8s.io/apimachinery/pkg/util/wait"
"k8s.io/apimachinery/pkg/watch"
"k8s.io/apiserver/pkg/audit"
@ -42,9 +41,9 @@ import (
"k8s.io/apiserver/pkg/storage"
"k8s.io/apiserver/pkg/storage/cacher/metrics"
utilfeature "k8s.io/apiserver/pkg/util/feature"
utilflowcontrol "k8s.io/apiserver/pkg/util/flowcontrol"
"k8s.io/client-go/tools/cache"
"k8s.io/component-base/tracing"
"k8s.io/klog/v2"
"k8s.io/utils/clock"
)
@ -1198,340 +1197,3 @@ func (c *errWatcher) ResultChan() <-chan watch.Event {
func (c *errWatcher) Stop() {
// no-op
}
// cacheWatcher implements watch.Interface
// this is not thread-safe
type cacheWatcher struct {
input chan *watchCacheEvent
result chan watch.Event
done chan struct{}
filter filterWithAttrsFunc
stopped bool
forget func(bool)
versioner storage.Versioner
// The watcher will be closed by server after the deadline,
// save it here to send bookmark events before that.
deadline time.Time
allowWatchBookmarks bool
groupResource schema.GroupResource
// human readable identifier that helps assigning cacheWatcher
// instance with request
identifier string
// drainInputBuffer indicates whether we should delay closing this watcher
// and send all event in the input buffer.
drainInputBuffer bool
}
func newCacheWatcher(
chanSize int,
filter filterWithAttrsFunc,
forget func(bool),
versioner storage.Versioner,
deadline time.Time,
allowWatchBookmarks bool,
groupResource schema.GroupResource,
identifier string,
) *cacheWatcher {
return &cacheWatcher{
input: make(chan *watchCacheEvent, chanSize),
result: make(chan watch.Event, chanSize),
done: make(chan struct{}),
filter: filter,
stopped: false,
forget: forget,
versioner: versioner,
deadline: deadline,
allowWatchBookmarks: allowWatchBookmarks,
groupResource: groupResource,
identifier: identifier,
}
}
// Implements watch.Interface.
func (c *cacheWatcher) ResultChan() <-chan watch.Event {
return c.result
}
// Implements watch.Interface.
func (c *cacheWatcher) Stop() {
c.forget(false)
}
// we rely on the fact that stopLocked is actually protected by Cacher.Lock()
func (c *cacheWatcher) stopLocked() {
if !c.stopped {
c.stopped = true
// stop without draining the input channel was requested.
if !c.drainInputBuffer {
close(c.done)
}
close(c.input)
}
// Even if the watcher was already stopped, if it previously was
// using draining mode and it's not using it now we need to
// close the done channel now. Otherwise we could leak the
// processing goroutine if it will be trying to put more objects
// into result channel, the channel will be full and there will
// already be noone on the processing the events on the receiving end.
if !c.drainInputBuffer && !c.isDoneChannelClosedLocked() {
close(c.done)
}
}
func (c *cacheWatcher) nonblockingAdd(event *watchCacheEvent) bool {
select {
case c.input <- event:
return true
default:
return false
}
}
// Nil timer means that add will not block (if it can't send event immediately, it will break the watcher)
func (c *cacheWatcher) add(event *watchCacheEvent, timer *time.Timer) bool {
// Try to send the event immediately, without blocking.
if c.nonblockingAdd(event) {
return true
}
closeFunc := func() {
// This means that we couldn't send event to that watcher.
// Since we don't want to block on it infinitely,
// we simply terminate it.
klog.V(1).Infof("Forcing %v watcher close due to unresponsiveness: %v. len(c.input) = %v, len(c.result) = %v", c.groupResource.String(), c.identifier, len(c.input), len(c.result))
metrics.TerminatedWatchersCounter.WithLabelValues(c.groupResource.String()).Inc()
c.forget(false)
}
if timer == nil {
closeFunc()
return false
}
// OK, block sending, but only until timer fires.
select {
case c.input <- event:
return true
case <-timer.C:
closeFunc()
return false
}
}
func (c *cacheWatcher) nextBookmarkTime(now time.Time, bookmarkFrequency time.Duration) (time.Time, bool) {
// We try to send bookmarks:
//
// (a) right before the watcher timeout - for now we simply set it 2s before
// the deadline
//
// (b) roughly every minute
//
// (b) gives us periodicity if the watch breaks due to unexpected
// conditions, (a) ensures that on timeout the watcher is as close to
// now as possible - this covers 99% of cases.
heartbeatTime := now.Add(bookmarkFrequency)
if c.deadline.IsZero() {
// Timeout is set by our client libraries (e.g. reflector) as well as defaulted by
// apiserver if properly configured. So this shoudln't happen in practice.
return heartbeatTime, true
}
if pretimeoutTime := c.deadline.Add(-2 * time.Second); pretimeoutTime.Before(heartbeatTime) {
heartbeatTime = pretimeoutTime
}
if heartbeatTime.Before(now) {
return time.Time{}, false
}
return heartbeatTime, true
}
// setDrainInputBufferLocked if set to true indicates that we should delay closing this watcher
// until we send all events residing in the input buffer.
func (c *cacheWatcher) setDrainInputBufferLocked(drain bool) {
c.drainInputBuffer = drain
}
// isDoneChannelClosed checks if c.done channel is closed
func (c *cacheWatcher) isDoneChannelClosedLocked() bool {
select {
case <-c.done:
return true
default:
}
return false
}
func getMutableObject(object runtime.Object) runtime.Object {
if _, ok := object.(*cachingObject); ok {
// It is safe to return without deep-copy, because the underlying
// object will lazily perform deep-copy on the first try to change
// any of its fields.
return object
}
return object.DeepCopyObject()
}
func updateResourceVersion(object runtime.Object, versioner storage.Versioner, resourceVersion uint64) {
if err := versioner.UpdateObject(object, resourceVersion); err != nil {
utilruntime.HandleError(fmt.Errorf("failure to version api object (%d) %#v: %v", resourceVersion, object, err))
}
}
func (c *cacheWatcher) convertToWatchEvent(event *watchCacheEvent) *watch.Event {
if event.Type == watch.Bookmark {
return &watch.Event{Type: watch.Bookmark, Object: event.Object.DeepCopyObject()}
}
curObjPasses := event.Type != watch.Deleted && c.filter(event.Key, event.ObjLabels, event.ObjFields)
oldObjPasses := false
if event.PrevObject != nil {
oldObjPasses = c.filter(event.Key, event.PrevObjLabels, event.PrevObjFields)
}
if !curObjPasses && !oldObjPasses {
// Watcher is not interested in that object.
return nil
}
switch {
case curObjPasses && !oldObjPasses:
return &watch.Event{Type: watch.Added, Object: getMutableObject(event.Object)}
case curObjPasses && oldObjPasses:
return &watch.Event{Type: watch.Modified, Object: getMutableObject(event.Object)}
case !curObjPasses && oldObjPasses:
// return a delete event with the previous object content, but with the event's resource version
oldObj := getMutableObject(event.PrevObject)
// We know that if oldObj is cachingObject (which can only be set via
// setCachingObjects), its resourceVersion is already set correctly and
// we don't need to update it. However, since cachingObject efficiently
// handles noop updates, we avoid this microoptimization here.
updateResourceVersion(oldObj, c.versioner, event.ResourceVersion)
return &watch.Event{Type: watch.Deleted, Object: oldObj}
}
return nil
}
// NOTE: sendWatchCacheEvent is assumed to not modify <event> !!!
func (c *cacheWatcher) sendWatchCacheEvent(event *watchCacheEvent) {
watchEvent := c.convertToWatchEvent(event)
if watchEvent == nil {
// Watcher is not interested in that object.
return
}
// We need to ensure that if we put event X to the c.result, all
// previous events were already put into it before, no matter whether
// c.done is close or not.
// Thus we cannot simply select from c.done and c.result and this
// would give us non-determinism.
// At the same time, we don't want to block infinitely on putting
// to c.result, when c.done is already closed.
//
// This ensures that with c.done already close, we at most once go
// into the next select after this. With that, no matter which
// statement we choose there, we will deliver only consecutive
// events.
select {
case <-c.done:
return
default:
}
select {
case c.result <- *watchEvent:
case <-c.done:
}
}
func (c *cacheWatcher) processInterval(ctx context.Context, cacheInterval *watchCacheInterval, resourceVersion uint64) {
defer utilruntime.HandleCrash()
defer close(c.result)
defer c.Stop()
// Check how long we are processing initEvents.
// As long as these are not processed, we are not processing
// any incoming events, so if it takes long, we may actually
// block all watchers for some time.
// TODO: From the logs it seems that there happens processing
// times even up to 1s which is very long. However, this doesn't
// depend that much on the number of initEvents. E.g. from the
// 2000-node Kubemark run we have logs like this, e.g.:
// ... processing 13862 initEvents took 66.808689ms
// ... processing 14040 initEvents took 993.532539ms
// We should understand what is blocking us in those cases (e.g.
// is it lack of CPU, network, or sth else) and potentially
// consider increase size of result buffer in those cases.
const initProcessThreshold = 500 * time.Millisecond
startTime := time.Now()
initEventCount := 0
for {
event, err := cacheInterval.Next()
if err != nil {
// An error indicates that the cache interval
// has been invalidated and can no longer serve
// events.
//
// Initially we considered sending an "out-of-history"
// Error event in this case, but because historically
// such events weren't sent out of the watchCache, we
// decided not to. This is still ok, because on watch
// closure, the watcher will try to re-instantiate the
// watch and then will get an explicit "out-of-history"
// window. There is potential for optimization, but for
// now, in order to be on the safe side and not break
// custom clients, the cost of it is something that we
// are fully accepting.
klog.Warningf("couldn't retrieve watch event to serve: %#v", err)
return
}
if event == nil {
break
}
c.sendWatchCacheEvent(event)
// With some events already sent, update resourceVersion so that
// events that were buffered and not yet processed won't be delivered
// to this watcher second time causing going back in time.
resourceVersion = event.ResourceVersion
initEventCount++
}
if initEventCount > 0 {
metrics.InitCounter.WithLabelValues(c.groupResource.String()).Add(float64(initEventCount))
}
processingTime := time.Since(startTime)
if processingTime > initProcessThreshold {
klog.V(2).Infof("processing %d initEvents of %s (%s) took %v", initEventCount, c.groupResource, c.identifier, processingTime)
}
c.process(ctx, resourceVersion)
}
func (c *cacheWatcher) process(ctx context.Context, resourceVersion uint64) {
// At this point we already start processing incoming watch events.
// However, the init event can still be processed because their serialization
// and sending to the client happens asynchrnously.
// TODO: As describe in the KEP, we would like to estimate that by delaying
// the initialization signal proportionally to the number of events to
// process, but we're leaving this to the tuning phase.
utilflowcontrol.WatchInitialized(ctx)
for {
select {
case event, ok := <-c.input:
if !ok {
return
}
// only send events newer than resourceVersion
if event.ResourceVersion > resourceVersion {
c.sendWatchCacheEvent(event)
}
case <-ctx.Done():
return
}
}
}

View File

@ -27,7 +27,6 @@ import (
"testing"
"time"
v1 "k8s.io/api/core/v1"
apiequality "k8s.io/apimachinery/pkg/api/equality"
"k8s.io/apimachinery/pkg/api/meta"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
@ -36,7 +35,6 @@ import (
"k8s.io/apimachinery/pkg/runtime"
"k8s.io/apimachinery/pkg/runtime/schema"
"k8s.io/apimachinery/pkg/runtime/serializer"
"k8s.io/apimachinery/pkg/util/diff"
utilruntime "k8s.io/apimachinery/pkg/util/runtime"
"k8s.io/apimachinery/pkg/util/wait"
"k8s.io/apimachinery/pkg/watch"
@ -45,174 +43,8 @@ import (
"k8s.io/apiserver/pkg/storage"
utilflowcontrol "k8s.io/apiserver/pkg/util/flowcontrol"
"k8s.io/utils/clock"
testingclock "k8s.io/utils/clock/testing"
)
// verifies the cacheWatcher.process goroutine is properly cleaned up even if
// the writes to cacheWatcher.result channel is blocked.
func TestCacheWatcherCleanupNotBlockedByResult(t *testing.T) {
var lock sync.RWMutex
var w *cacheWatcher
count := 0
filter := func(string, labels.Set, fields.Set) bool { return true }
forget := func(drainWatcher bool) {
lock.Lock()
defer lock.Unlock()
count++
// forget() has to stop the watcher, as only stopping the watcher
// triggers stopping the process() goroutine which we are in the
// end waiting for in this test.
w.setDrainInputBufferLocked(drainWatcher)
w.stopLocked()
}
initEvents := []*watchCacheEvent{
{Object: &v1.Pod{}},
{Object: &v1.Pod{}},
}
// set the size of the buffer of w.result to 0, so that the writes to
// w.result is blocked.
w = newCacheWatcher(0, filter, forget, testVersioner{}, time.Now(), false, schema.GroupResource{Resource: "pods"}, "")
go w.processInterval(context.Background(), intervalFromEvents(initEvents), 0)
w.Stop()
if err := wait.PollImmediate(1*time.Second, 5*time.Second, func() (bool, error) {
lock.RLock()
defer lock.RUnlock()
return count == 2, nil
}); err != nil {
t.Fatalf("expected forget() to be called twice, because sendWatchCacheEvent should not be blocked by the result channel: %v", err)
}
}
func TestCacheWatcherHandlesFiltering(t *testing.T) {
filter := func(_ string, _ labels.Set, field fields.Set) bool {
return field["spec.nodeName"] == "host"
}
forget := func(bool) {}
testCases := []struct {
events []*watchCacheEvent
expected []watch.Event
}{
// properly handle starting with the filter, then being deleted, then re-added
{
events: []*watchCacheEvent{
{
Type: watch.Added,
Object: &v1.Pod{ObjectMeta: metav1.ObjectMeta{ResourceVersion: "1"}},
ObjFields: fields.Set{"spec.nodeName": "host"},
ResourceVersion: 1,
},
{
Type: watch.Modified,
PrevObject: &v1.Pod{ObjectMeta: metav1.ObjectMeta{ResourceVersion: "1"}},
PrevObjFields: fields.Set{"spec.nodeName": "host"},
Object: &v1.Pod{ObjectMeta: metav1.ObjectMeta{ResourceVersion: "2"}},
ObjFields: fields.Set{"spec.nodeName": ""},
ResourceVersion: 2,
},
{
Type: watch.Modified,
PrevObject: &v1.Pod{ObjectMeta: metav1.ObjectMeta{ResourceVersion: "2"}},
PrevObjFields: fields.Set{"spec.nodeName": ""},
Object: &v1.Pod{ObjectMeta: metav1.ObjectMeta{ResourceVersion: "3"}},
ObjFields: fields.Set{"spec.nodeName": "host"},
ResourceVersion: 3,
},
},
expected: []watch.Event{
{Type: watch.Added, Object: &v1.Pod{ObjectMeta: metav1.ObjectMeta{ResourceVersion: "1"}}},
{Type: watch.Deleted, Object: &v1.Pod{ObjectMeta: metav1.ObjectMeta{ResourceVersion: "2"}}},
{Type: watch.Added, Object: &v1.Pod{ObjectMeta: metav1.ObjectMeta{ResourceVersion: "3"}}},
},
},
// properly handle ignoring changes prior to the filter, then getting added, then deleted
{
events: []*watchCacheEvent{
{
Type: watch.Added,
Object: &v1.Pod{ObjectMeta: metav1.ObjectMeta{ResourceVersion: "1"}},
ObjFields: fields.Set{"spec.nodeName": ""},
ResourceVersion: 1,
},
{
Type: watch.Modified,
PrevObject: &v1.Pod{ObjectMeta: metav1.ObjectMeta{ResourceVersion: "1"}},
PrevObjFields: fields.Set{"spec.nodeName": ""},
Object: &v1.Pod{ObjectMeta: metav1.ObjectMeta{ResourceVersion: "2"}},
ObjFields: fields.Set{"spec.nodeName": ""},
ResourceVersion: 2,
},
{
Type: watch.Modified,
PrevObject: &v1.Pod{ObjectMeta: metav1.ObjectMeta{ResourceVersion: "2"}},
PrevObjFields: fields.Set{"spec.nodeName": ""},
Object: &v1.Pod{ObjectMeta: metav1.ObjectMeta{ResourceVersion: "3"}},
ObjFields: fields.Set{"spec.nodeName": "host"},
ResourceVersion: 3,
},
{
Type: watch.Modified,
PrevObject: &v1.Pod{ObjectMeta: metav1.ObjectMeta{ResourceVersion: "3"}},
PrevObjFields: fields.Set{"spec.nodeName": "host"},
Object: &v1.Pod{ObjectMeta: metav1.ObjectMeta{ResourceVersion: "4"}},
ObjFields: fields.Set{"spec.nodeName": "host"},
ResourceVersion: 4,
},
{
Type: watch.Modified,
PrevObject: &v1.Pod{ObjectMeta: metav1.ObjectMeta{ResourceVersion: "4"}},
PrevObjFields: fields.Set{"spec.nodeName": "host"},
Object: &v1.Pod{ObjectMeta: metav1.ObjectMeta{ResourceVersion: "5"}},
ObjFields: fields.Set{"spec.nodeName": ""},
ResourceVersion: 5,
},
{
Type: watch.Modified,
PrevObject: &v1.Pod{ObjectMeta: metav1.ObjectMeta{ResourceVersion: "5"}},
PrevObjFields: fields.Set{"spec.nodeName": ""},
Object: &v1.Pod{ObjectMeta: metav1.ObjectMeta{ResourceVersion: "6"}},
ObjFields: fields.Set{"spec.nodeName": ""},
ResourceVersion: 6,
},
},
expected: []watch.Event{
{Type: watch.Added, Object: &v1.Pod{ObjectMeta: metav1.ObjectMeta{ResourceVersion: "3"}}},
{Type: watch.Modified, Object: &v1.Pod{ObjectMeta: metav1.ObjectMeta{ResourceVersion: "4"}}},
{Type: watch.Deleted, Object: &v1.Pod{ObjectMeta: metav1.ObjectMeta{ResourceVersion: "5"}}},
},
},
}
TestCase:
for i, testCase := range testCases {
// set the size of the buffer of w.result to 0, so that the writes to
// w.result is blocked.
for j := range testCase.events {
testCase.events[j].ResourceVersion = uint64(j) + 1
}
w := newCacheWatcher(0, filter, forget, testVersioner{}, time.Now(), false, schema.GroupResource{Resource: "pods"}, "")
go w.processInterval(context.Background(), intervalFromEvents(testCase.events), 0)
ch := w.ResultChan()
for j, event := range testCase.expected {
e := <-ch
if !reflect.DeepEqual(event, e) {
t.Errorf("%d: unexpected event %d: %s", i, j, diff.ObjectReflectDiff(event, e))
break TestCase
}
}
select {
case obj, ok := <-ch:
t.Errorf("%d: unexpected excess event: %#v %t", i, obj, ok)
break TestCase
default:
}
w.setDrainInputBufferLocked(false)
w.stopLocked()
}
}
type testVersioner struct{}
func (testVersioner) UpdateObject(obj runtime.Object, resourceVersion uint64) error {
@ -567,89 +399,6 @@ func TestWatcherNotGoingBackInTime(t *testing.T) {
}
}
func TestCacheWatcherStoppedInAnotherGoroutine(t *testing.T) {
var w *cacheWatcher
done := make(chan struct{})
filter := func(string, labels.Set, fields.Set) bool { return true }
forget := func(drainWatcher bool) {
w.setDrainInputBufferLocked(drainWatcher)
w.stopLocked()
done <- struct{}{}
}
maxRetriesToProduceTheRaceCondition := 1000
// Simulating the timer is fired and stopped concurrently by set time
// timeout to zero and run the Stop goroutine concurrently.
// May sure that the watch will not be blocked on Stop.
for i := 0; i < maxRetriesToProduceTheRaceCondition; i++ {
w = newCacheWatcher(0, filter, forget, testVersioner{}, time.Now(), false, schema.GroupResource{Resource: "pods"}, "")
go w.Stop()
select {
case <-done:
case <-time.After(time.Second):
t.Fatal("stop is blocked when the timer is fired concurrently")
}
}
deadline := time.Now().Add(time.Hour)
// After that, verifies the cacheWatcher.process goroutine works correctly.
for i := 0; i < maxRetriesToProduceTheRaceCondition; i++ {
w = newCacheWatcher(2, filter, emptyFunc, testVersioner{}, deadline, false, schema.GroupResource{Resource: "pods"}, "")
w.input <- &watchCacheEvent{Object: &v1.Pod{}, ResourceVersion: uint64(i + 1)}
ctx, cancel := context.WithDeadline(context.Background(), deadline)
defer cancel()
go w.processInterval(ctx, intervalFromEvents(nil), 0)
select {
case <-w.ResultChan():
case <-time.After(time.Second):
t.Fatal("expected received a event on ResultChan")
}
w.setDrainInputBufferLocked(false)
w.stopLocked()
}
}
func TestCacheWatcherStoppedOnDestroy(t *testing.T) {
backingStorage := &dummyStorage{}
cacher, _, err := newTestCacher(backingStorage)
if err != nil {
t.Fatalf("Couldn't create cacher: %v", err)
}
defer cacher.Stop()
// Wait until cacher is initialized.
if err := cacher.ready.wait(); err != nil {
t.Fatalf("unexpected error waiting for the cache to be ready")
}
w, err := cacher.Watch(context.Background(), "pods/ns", storage.ListOptions{ResourceVersion: "0", Predicate: storage.Everything})
if err != nil {
t.Fatalf("Failed to create watch: %v", err)
}
watchClosed := make(chan struct{})
go func() {
defer close(watchClosed)
for event := range w.ResultChan() {
switch event.Type {
case watch.Added, watch.Modified, watch.Deleted:
// ok
default:
t.Errorf("unexpected event %#v", event)
}
}
}()
cacher.Stop()
select {
case <-watchClosed:
case <-time.After(wait.ForeverTestTimeout):
t.Errorf("timed out waiting for watch to close")
}
}
func TestCacheDontAcceptRequestsStopped(t *testing.T) {
backingStorage := &dummyStorage{}
cacher, _, err := newTestCacher(backingStorage)
@ -712,48 +461,6 @@ func TestCacheDontAcceptRequestsStopped(t *testing.T) {
}
}
func TestTimeBucketWatchersBasic(t *testing.T) {
filter := func(_ string, _ labels.Set, _ fields.Set) bool {
return true
}
forget := func(bool) {}
newWatcher := func(deadline time.Time) *cacheWatcher {
return newCacheWatcher(0, filter, forget, testVersioner{}, deadline, true, schema.GroupResource{Resource: "pods"}, "")
}
clock := testingclock.NewFakeClock(time.Now())
watchers := newTimeBucketWatchers(clock, defaultBookmarkFrequency)
now := clock.Now()
watchers.addWatcher(newWatcher(now.Add(10 * time.Second)))
watchers.addWatcher(newWatcher(now.Add(20 * time.Second)))
watchers.addWatcher(newWatcher(now.Add(20 * time.Second)))
if len(watchers.watchersBuckets) != 2 {
t.Errorf("unexpected bucket size: %#v", watchers.watchersBuckets)
}
watchers0 := watchers.popExpiredWatchers()
if len(watchers0) != 0 {
t.Errorf("unexpected bucket size: %#v", watchers0)
}
clock.Step(10 * time.Second)
watchers1 := watchers.popExpiredWatchers()
if len(watchers1) != 1 || len(watchers1[0]) != 1 {
t.Errorf("unexpected bucket size: %v", watchers1)
}
watchers1 = watchers.popExpiredWatchers()
if len(watchers1) != 0 {
t.Errorf("unexpected bucket size: %#v", watchers1)
}
clock.Step(12 * time.Second)
watchers2 := watchers.popExpiredWatchers()
if len(watchers2) != 1 || len(watchers2[0]) != 2 {
t.Errorf("unexpected bucket size: %#v", watchers2)
}
}
func TestCacherNoLeakWithMultipleWatchers(t *testing.T) {
backingStorage := &dummyStorage{}
cacher, _, err := newTestCacher(backingStorage)
@ -1630,90 +1337,3 @@ func TestCacheIntervalInvalidationStopsWatch(t *testing.T) {
t.Errorf("unexpected number of events received, expected: %d, got: %d", bufferSize+1, received)
}
}
func makeWatchCacheEvent(rv uint64) *watchCacheEvent {
return &watchCacheEvent{
Type: watch.Added,
Object: &v1.Pod{
ObjectMeta: metav1.ObjectMeta{
Name: fmt.Sprintf("pod-%d", rv),
ResourceVersion: fmt.Sprintf("%d", rv),
},
},
ResourceVersion: rv,
}
}
// TestCacheWatcherDraining verifies the cacheWatcher.process goroutine is properly cleaned up when draining was requested
func TestCacheWatcherDraining(t *testing.T) {
var lock sync.RWMutex
var w *cacheWatcher
count := 0
filter := func(string, labels.Set, fields.Set) bool { return true }
forget := func(drainWatcher bool) {
lock.Lock()
defer lock.Unlock()
count++
w.setDrainInputBufferLocked(drainWatcher)
w.stopLocked()
}
initEvents := []*watchCacheEvent{
makeWatchCacheEvent(5),
makeWatchCacheEvent(6),
}
w = newCacheWatcher(1, filter, forget, testVersioner{}, time.Now(), true, schema.GroupResource{Resource: "pods"}, "")
go w.processInterval(context.Background(), intervalFromEvents(initEvents), 1)
if !w.add(makeWatchCacheEvent(7), time.NewTimer(1*time.Second)) {
t.Fatal("failed adding an even to the watcher")
}
forget(true) // drain the watcher
eventCount := 0
for range w.ResultChan() {
eventCount++
}
if eventCount != 3 {
t.Errorf("Unexpected number of objects received: %d, expected: 3", eventCount)
}
if err := wait.PollImmediate(1*time.Second, 5*time.Second, func() (bool, error) {
lock.RLock()
defer lock.RUnlock()
return count == 2, nil
}); err != nil {
t.Fatalf("expected forget() to be called twice, because processInterval should call Stop(): %v", err)
}
}
// TestCacheWatcherDrainingRequestedButNotDrained verifies the cacheWatcher.process goroutine is properly cleaned up when draining was requested
// but the client never actually get any data
func TestCacheWatcherDrainingRequestedButNotDrained(t *testing.T) {
var lock sync.RWMutex
var w *cacheWatcher
count := 0
filter := func(string, labels.Set, fields.Set) bool { return true }
forget := func(drainWatcher bool) {
lock.Lock()
defer lock.Unlock()
count++
w.setDrainInputBufferLocked(drainWatcher)
w.stopLocked()
}
initEvents := []*watchCacheEvent{
makeWatchCacheEvent(5),
makeWatchCacheEvent(6),
}
w = newCacheWatcher(1, filter, forget, testVersioner{}, time.Now(), true, schema.GroupResource{Resource: "pods"}, "")
go w.processInterval(context.Background(), intervalFromEvents(initEvents), 1)
if !w.add(makeWatchCacheEvent(7), time.NewTimer(1*time.Second)) {
t.Fatal("failed adding an even to the watcher")
}
forget(true) // drain the watcher
w.Stop() // client disconnected, timeout expired or ctx was actually closed
if err := wait.PollImmediate(1*time.Second, 5*time.Second, func() (bool, error) {
lock.RLock()
defer lock.RUnlock()
return count == 3, nil
}); err != nil {
t.Fatalf("expected forget() to be called three times, because processInterval should call Stop(): %v", err)
}
}