Remove old reason cache

pkg/kubelet/dockertools/manager.go

@@ -33,7 +33,6 @@ import (
 	"github.com/coreos/go-semver/semver"
 	docker "github.com/fsouza/go-dockerclient"
 	"github.com/golang/glog"
-	"github.com/golang/groupcache/lru"
 	cadvisorapi "github.com/google/cadvisor/info/v1"
 	"k8s.io/kubernetes/pkg/api"
 	"k8s.io/kubernetes/pkg/api/unversioned"
@@ -62,8 +61,6 @@ const (
 
 	MinimumDockerAPIVersion = "1.18"
 
-	maxReasonCacheEntries = 200
-
 	// ndots specifies the minimum number of dots that a domain name must contain for the resolver to consider it as FQDN (fully-qualified)
 	// we want to able to consider SRV lookup names like _dns._udp.kube-dns.default.svc to be considered relative.
 	// hence, setting ndots to be 5.
@@ -98,15 +95,7 @@ type DockerManager struct {
 
 	// The image name of the pod infra container.
 	podInfraContainerImage string
-	// reasonCache stores the failure reason of the last container creation
+
-	// and/or start in a string, keyed by <pod_UID>_<container_name>. The goal
-	// is to propagate this reason to the container status. This endeavor is
-	// "best-effort" for two reasons:
-	//   1. The cache is not persisted.
-	//   2. We use an LRU cache to avoid extra garbage collection work. This
-	//      means that some entries may be recycled before a pod has been
-	//      deleted.
-	reasonCache reasonInfoCache
 	// TODO(yifan): Record the pull failure so we can eliminate the image checking?
 	// Lower level docker image puller.
 	dockerPuller DockerPuller
@@ -185,8 +174,6 @@ func NewDockerManager(
 		glog.Infof("Setting dockerRoot to %s", dockerRoot)
 	}
 
-	reasonCache := reasonInfoCache{cache: lru.New(maxReasonCacheEntries)}
-
 	dm := &DockerManager{
 		client:                 client,
 		recorder:               recorder,
@@ -194,7 +181,6 @@ func NewDockerManager(
 		os:                     osInterface,
 		machineInfo:            machineInfo,
 		podInfraContainerImage: podInfraContainerImage,
-		reasonCache:            reasonCache,
 		dockerPuller:           newDockerPuller(client, qps, burst),
 		dockerRoot:             dockerRoot,
 		containerLogsDir:       containerLogsDir,
@@ -218,43 +204,6 @@ func NewDockerManager(
 	return dm
 }
 
-// A cache which stores strings keyed by <pod_UID>_<container_name>.
-type reasonInfoCache struct {
-	lock  sync.RWMutex
-	cache *lru.Cache
-}
-type reasonInfo struct {
-	reason  string
-	message string
-}
-
-func (sc *reasonInfoCache) composeKey(uid types.UID, name string) string {
-	return fmt.Sprintf("%s_%s", uid, name)
-}
-
-func (sc *reasonInfoCache) Add(uid types.UID, name string, reason, message string) {
-	sc.lock.Lock()
-	defer sc.lock.Unlock()
-	sc.cache.Add(sc.composeKey(uid, name), reasonInfo{reason, message})
-}
-
-func (sc *reasonInfoCache) Remove(uid types.UID, name string) {
-	sc.lock.Lock()
-	defer sc.lock.Unlock()
-	sc.cache.Remove(sc.composeKey(uid, name))
-}
-
-func (sc *reasonInfoCache) Get(uid types.UID, name string) (reasonInfo, bool) {
-	sc.lock.RLock()
-	defer sc.lock.RUnlock()
-	value, ok := sc.cache.Get(sc.composeKey(uid, name))
-	if ok {
-		return value.(reasonInfo), ok
-	} else {
-		return reasonInfo{"", ""}, ok
-	}
-}
-
 // GetContainerLogs returns logs of a specific container. By
 // default, it returns a snapshot of the container log. Set 'follow' to true to
 // stream the log. Set 'follow' to false and specify the number of lines (e.g.
@@ -1682,20 +1631,6 @@ func (dm *DockerManager) computePodContainerChanges(pod *api.Pod, podStatus *kub
 	}, nil
 }
 
-// updateReasonCache updates the failure reason based on the registered error.
-func (dm *DockerManager) updateReasonCache(pod *api.Pod, container *api.Container, briefError string, err error) {
-	if briefError == "" || err == nil {
-		return
-	}
-	errString := err.Error()
-	dm.reasonCache.Add(pod.UID, container.Name, briefError, errString)
-}
-
-// clearReasonCache removes the entry in the reason cache.
-func (dm *DockerManager) clearReasonCache(pod *api.Pod, container *api.Container) {
-	dm.reasonCache.Remove(pod.UID, container.Name)
-}
-
 // Sync the running pod to match the specified desired pod.
 func (dm *DockerManager) SyncPod(pod *api.Pod, _ api.PodStatus, podStatus *kubecontainer.PodStatus, pullSecrets []api.Secret, backOff *util.Backoff) (result kubecontainer.PodSyncResult) {
 	start := time.Now()
@@ -1836,13 +1771,11 @@ func (dm *DockerManager) SyncPod(pod *api.Pod, _ api.PodStatus, podStatus *kubec
 		err, msg := dm.imagePuller.PullImage(pod, container, pullSecrets)
 		if err != nil {
 			startContainerResult.Fail(err, msg)
-			dm.updateReasonCache(pod, container, err.Error(), errors.New(msg))
 			continue
 		}
 
 		if container.SecurityContext != nil && container.SecurityContext.RunAsNonRoot != nil && *container.SecurityContext.RunAsNonRoot {
 			err := dm.verifyNonRoot(container)
-			dm.updateReasonCache(pod, container, kubecontainer.ErrVerifyNonRoot.Error(), err)
 			if err != nil {
 				startContainerResult.Fail(kubecontainer.ErrVerifyNonRoot, err.Error())
 				glog.Errorf("Error running pod %q container %q: %v", format.Pod(pod), container.Name, err)
@@ -1863,7 +1796,6 @@ func (dm *DockerManager) SyncPod(pod *api.Pod, _ api.PodStatus, podStatus *kubec
 		// See createPodInfraContainer for infra container setup.
 		namespaceMode := fmt.Sprintf("container:%v", podInfraContainerID)
 		_, err = dm.runContainerInPod(pod, container, namespaceMode, namespaceMode, getPidMode(pod), restartCount)
-		dm.updateReasonCache(pod, container, kubecontainer.ErrRunContainer.Error(), err)
 		if err != nil {
 			startContainerResult.Fail(kubecontainer.ErrRunContainer, err.Error())
 			// TODO(bburns) : Perhaps blacklist a container after N failures?
@@ -1871,8 +1803,6 @@ func (dm *DockerManager) SyncPod(pod *api.Pod, _ api.PodStatus, podStatus *kubec
 			continue
 		}
 		// Successfully started the container; clear the entry in the failure
-		// reason cache.
-		dm.clearReasonCache(pod, container)
 	}
 	return
 }
@@ -1955,14 +1885,12 @@ func (dm *DockerManager) doBackOff(pod *api.Pod, container *api.Container, podSt
 				dm.recorder.Eventf(ref, api.EventTypeWarning, kubecontainer.BackOffStartContainer, "Back-off restarting failed docker container")
 			}
 			err := fmt.Errorf("Back-off %s restarting failed container=%s pod=%s", backOff.Get(stableName), container.Name, format.Pod(pod))
-			dm.updateReasonCache(pod, container, kubecontainer.ErrCrashLoopBackOff.Error(), err)
 			glog.Infof("%s", err.Error())
 			return true, kubecontainer.ErrCrashLoopBackOff, err.Error()
 		}
 		backOff.Next(stableName, ts)
 
 	}
-	dm.clearReasonCache(pod, container)
 	return false, nil, ""
 }