Merge pull request #111932 from azylinski/rm-lastContainerStartedTime-lru

Cleanup: Remove unused lastContainerStartedTime time.Cache lru

pkg/kubelet/kubelet.go

@@ -528,7 +528,6 @@ func NewMainKubelet(kubeCfg *kubeletconfiginternal.KubeletConfiguration,
 		experimentalHostUserNamespaceDefaulting: utilfeature.DefaultFeatureGate.Enabled(features.ExperimentalHostUserNamespaceDefaultingGate),
 		keepTerminatedPodVolumes:                keepTerminatedPodVolumes,
 		nodeStatusMaxImages:                     nodeStatusMaxImages,
-		lastContainerStartedTime:                newTimeCache(),
 	}
 
 	if klet.cloud != nil {
@@ -1027,9 +1026,6 @@ type Kubelet struct {
 	// lastStatusReportTime is the time when node status was last reported.
 	lastStatusReportTime time.Time
 
-	// lastContainerStartedTime is the time of the last ContainerStarted event observed per pod
-	lastContainerStartedTime *timeCache
-
 	// syncNodeStatusMux is a lock on updating the node status, because this path is not thread-safe.
 	// This lock is used by Kubelet.syncNodeStatus function and shouldn't be used anywhere else.
 	syncNodeStatusMux sync.Mutex
@@ -2122,12 +2118,6 @@ func (kl *Kubelet) syncLoopIteration(configCh <-chan kubetypes.PodUpdate, handle
 		kl.sourcesReady.AddSource(u.Source)
 
 	case e := <-plegCh:
-		if e.Type == pleg.ContainerStarted {
-			// record the most recent time we observed a container start for this pod.
-			// this lets us selectively invalidate the runtimeCache when processing a delete for this pod
-			// to make sure we don't miss handling graceful termination for containers we reported as having started.
-			kl.lastContainerStartedTime.Add(e.ID, time.Now())
-		}
 		if isSyncPodWorthy(e) {
 			// PLEG event for a pod; sync it.
 			if pod, ok := kl.podManager.GetPodByUID(e.ID); ok {

pkg/kubelet/kubelet_test.go

@@ -388,7 +388,6 @@ func newTestKubeletWithImageList(
 
 	kubelet.AddPodSyncLoopHandler(activeDeadlineHandler)
 	kubelet.AddPodSyncHandler(activeDeadlineHandler)
-	kubelet.lastContainerStartedTime = newTimeCache()
 	kubelet.kubeletConfiguration.LocalStorageCapacityIsolation = localStorageCapacityIsolation
 	return &TestKubelet{kubelet, fakeRuntime, fakeContainerManager, fakeKubeClient, fakeMirrorClient, fakeClock, nil, plug}
 }

pkg/kubelet/time_cache.go

@@ -1,67 +0,0 @@
-/*
-Copyright 2020 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 kubelet
-
-import (
-	"sync"
-	"time"
-
-	"github.com/golang/groupcache/lru"
-
-	"k8s.io/apimachinery/pkg/types"
-)
-
-// timeCache stores a time keyed by uid
-type timeCache struct {
-	lock  sync.Mutex
-	cache *lru.Cache
-}
-
-// maxTimeCacheEntries is the cache entry number in lru cache. 1000 is a proper number
-// for our 100 pods per node target. If we support more pods per node in the future, we
-// may want to increase the number.
-const maxTimeCacheEntries = 1000
-
-func newTimeCache() *timeCache {
-	return &timeCache{cache: lru.New(maxTimeCacheEntries)}
-}
-
-func (c *timeCache) Add(uid types.UID, t time.Time) {
-	c.lock.Lock()
-	defer c.lock.Unlock()
-	c.cache.Add(uid, t)
-}
-
-func (c *timeCache) Remove(uid types.UID) {
-	c.lock.Lock()
-	defer c.lock.Unlock()
-	c.cache.Remove(uid)
-}
-
-func (c *timeCache) Get(uid types.UID) (time.Time, bool) {
-	c.lock.Lock()
-	defer c.lock.Unlock()
-	value, ok := c.cache.Get(uid)
-	if !ok {
-		return time.Time{}, false
-	}
-	t, ok := value.(time.Time)
-	if !ok {
-		return time.Time{}, false
-	}
-	return t, true
-}

pkg/kubelet/time_cache_test.go

@@ -1,55 +0,0 @@
-/*
-Copyright 2020 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 kubelet
-
-import (
-	"testing"
-	"time"
-
-	"github.com/golang/groupcache/lru"
-)
-
-func TestTimeCache(t *testing.T) {
-	cache := &timeCache{cache: lru.New(2)}
-	if a, ok := cache.Get("123"); ok {
-		t.Errorf("expected cache miss, got %v, %v", a, ok)
-	}
-
-	now := time.Now()
-	soon := now.Add(time.Minute)
-	cache.Add("now", now)
-	cache.Add("soon", soon)
-
-	if a, ok := cache.Get("now"); !ok || !a.Equal(now) {
-		t.Errorf("expected cache hit matching %v, got %v, %v", now, a, ok)
-	}
-	if a, ok := cache.Get("soon"); !ok || !a.Equal(soon) {
-		t.Errorf("expected cache hit matching %v, got %v, %v", soon, a, ok)
-	}
-
-	then := now.Add(-time.Minute)
-	cache.Add("then", then)
-	if a, ok := cache.Get("now"); ok {
-		t.Errorf("expected cache miss from oldest evicted value, got %v, %v", a, ok)
-	}
-	if a, ok := cache.Get("soon"); !ok || !a.Equal(soon) {
-		t.Errorf("expected cache hit matching %v, got %v, %v", soon, a, ok)
-	}
-	if a, ok := cache.Get("then"); !ok || !a.Equal(then) {
-		t.Errorf("expected cache hit matching %v, got %v, %v", then, a, ok)
-	}
-}