// how this struct is updated on heartbeats and can guide customized reporter implementations.
message EventSeries {
  // count is the number of occurrences in this series up to the last heartbeat time.
  optional int32 count = 1;

  // lastObservedTime is the time when last Event from the series was seen before last heartbeat.
  optional k8s.io.apimachinery.pkg.apis.meta.v1.MicroTime lastObservedTime = 2;

// continuously for some time.
message EventSeries {
  // count is the number of occurrences in this series up to the last heartbeat time.
  optional int32 count = 1;

  // lastObservedTime is the time when last Event from the series was seen before last heartbeat.
  optional k8s.io.apimachinery.pkg.apis.meta.v1.MicroTime lastObservedTime = 2;

		return nil
	}
	clnt.SetCustomTransport(globalRemoteTargetTransport)
	return clnt
}

// heartBeat performs liveness check on remote endpoints.
func (sys *BucketTargetSys) heartBeat(ctx context.Context) {
	hcTimer := time.NewTimer(defaultHealthCheckDuration)
	defer hcTimer.Stop()
	for {
		select {
		case <-hcTimer.C:
			sys.hMutex.RLock()

focused on stability and performance improvements in the 1.13 release.  A new alpha feature is introduced to improve the mechanism that nodes heartbeat back to the control plane.  The `NodeLease` feature results in the node using a `Lease` resource in the `kube-node-lease` namespace that is renewed periodically.  The `NodeStatus` that was used previously to heartbeat back to the control plane is only updated when it changes.  This reduces load on the control plane for large clusters. The Kubelet plugin...

- kubelet: fix fail to close kubelet->API connections on heartbeat failure when bootstrapping or client certificate rotation is disabled ([#78016](https://github.com/kubernetes/kubernetes/pull/78016), [@gaorong](https://github.com/gaorong))

}

// EventSeries contain information on series of events, i.e. thing that was/is happening
// continuously for some time.
message EventSeries {
  // Number of occurrences in this series up to the last heartbeat time
  optional int32 count = 1;

  // Time of the last occurrence observed
  optional k8s.io.apimachinery.pkg.apis.meta.v1.MicroTime lastObservedTime = 2;
}

- The kubelet no longer forcefully closes active connections on heartbeat failures, using the HTTP2 health check mechanism to detect broken connections. Users can force the previous behavior of the kubelet by setting the environment variable DISABLE_HTTP2. ([#108107](https://github.com/kubernetes/kubernetes/pull/108107),...