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//// pkg/kubelet/pleg/generic.go - Healthy()

// The threshold needs to be greater than the relisting period + the
// relisting time, which can vary significantly. Set a conservative
// threshold to avoid flipping between healthy and unhealthy.
relistThreshold = 3 * time.Minute
:
func (g *GenericPLEG) Healthy() (bool, error) {
  relistTime := g.getRelistTime()

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//// pkg/kubelet/kubelet.go - NewMainKubelet()

// Generic PLEG relies on relisting for discovering container events.
// A longer period means that kubelet will take longer to detect container
// changes and to update pod status. On the other hand, a shorter period
// will cause more frequent relisting (e.g., container runtime operations),
// leading to higher cpu usage.
// Note that even though we set the period to 1s, the relisting itself can
// take more than 1s to finish if the container runtime responds slowly

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//// pkg/kubelet/pleg/generic.go - relist()
  :
  // get a current timestamp
  timestamp := g.clock.Now()

  // kubelet_pleg_relist_latency_microseconds for prometheus metrics
	defer func() {
		metrics.PLEGRelistLatency.Observe(metrics.SinceInMicroseconds(timestamp))
	}()

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//// pkg/kubelet/pleg/generic.go - relist()
  :
  // get a current timestamp
  timestamp := g.clock.Now()

  // kubelet_pleg_relist_latency_microseconds for prometheus metrics
	defer func() {
		metrics.PLEGRelistLatency.Observe(metrics.SinceInMicroseconds(timestamp))
	}()

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//// pkg/kubelet/kuberuntime/kuberuntime_manager.go - GetPods()

// GetPods returns a list of containers grouped by pods. The boolean parameter
// specifies whether the runtime returns all containers including those already
// exited and dead containers (used for garbage collection).
func (m *kubeGenericRuntimeManager) GetPods(all bool) ([]*kubecontainer.Pod, error) {
	pods := make(map[kubetypes.UID]*kubecontainer.Pod)
	sandboxes, err := m.getKubeletSandboxes(all)
:

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//// pkg/kubelet/pleg/generic.go - relist()
  // update as a current timestamp
  g.updateRelistTime(timestamp)

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//// pkg/kubelet/pleg/generic.go - relist()

  pods := kubecontainer.Pods(podList)
  g.podRecords.setCurrent(pods)

  // Compare the old and the current pods, and generate events.
  eventsByPodID := map[types.UID][]*PodLifecycleEvent{}
  for pid := range g.podRecords {
 oldPod := g.podRecords.getOld(pid)

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//// pkg/kubelet/pleg/generic.go - computeEvents()

func computeEvents(oldPod, newPod *kubecontainer.Pod, cid *kubecontainer.ContainerID) []*PodLifecycleEvent {
:
    return generateEvents(pid, cid.ID, oldState, newState)
}

//// pkg/kubelet/pleg/generic.go - generateEvents()

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//// pkg/kubelet/pleg/generic.go - relist()

  // If there are events associated with a pod, we should update the
  // podCache.
  for pid, events := range eventsByPodID {
    pod := g.podRecords.getCurrent(pid)
    if g.cacheEnabled() {
      // updateCache() will inspect the pod and update the cache. If an
      // error occurs during the inspection, we want PLEG to retry again

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//// pkg/kubelet/pleg/generic.go - updateCache()

func (g *GenericPLEG) updateCache(pod *kubecontainer.Pod, pid types.UID) error {
:
	timestamp := g.clock.Now()
	// TODO: Consider adding a new runtime method
	// GetPodStatus(pod *kubecontainer.Pod) so that Docker can avoid listing
	// all containers again.
	status, err := g.runtime.GetPodStatus(pod.ID, pod.Name, pod.Namespace)