### Feature

- Add flag --lease-max-object-size and metric etcd_lease_object_counts for kube-apiserver to config and observe max objects attached to a single etcd lease. ([#97480](https://github.com/kubernetes/kubernetes/pull/97480), [@lingsamuel](https://github.com/lingsamuel)) [SIG API Machinery, Instrumentation and Scalability]

- Kube-apiserver now maintains a Lease object to identify itself: 
  - The feature is under feature gate `APIServerIdentity`. 
  - Two flags are added to kube-apiserver: `identity-lease-duration-seconds`, `identity-lease-renew-interval-seconds` ([#95533](https://github.com/kubernetes/kubernetes/pull/95533), [@roycaihw](https://github.com/roycaihw)) [SIG API Machinery]

- Enable cAdvisor ProcessMetrics collecting. ([#79002](https://github.com/kubernetes/kubernetes/pull/79002), [@jiayingz](https://github.com/jiayingz))
- kubelet: change `node-lease-renew-interval` to 0.25 of lease-renew-duration ([#80429](https://github.com/kubernetes/kubernetes/pull/80429), [@gaorong](https://github.com/gaorong))

implementation must:
</p>

<ul>
	<li>Represent integer constants with at least 256 bits.</li>

	<li>Represent floating-point constants, including the parts of
	    a complex constant, with a mantissa of at least 256 bits
	    and a signed binary exponent of at least 16 bits.</li>

	<li>Give an error if unable to represent an integer constant
	    precisely.</li>

* Updates Fluentd to 1.3.2 & added filter_parser  ([#71180](https://github.com/kubernetes/kubernetes/pull/71180), [@monotek](https://github.com/monotek))
* The leaderelection package allows the lease holder to release its lease when the calling context is cancelled. This allows ([#71490](https://github.com/kubernetes/kubernetes/pull/71490), [@smarterclayton](https://github.com/smarterclayton))

  // Running: The pod has been bound to a node, and all of the containers have been created.
  // At least one container is still running, or is in the process of starting or restarting.
  // Succeeded: All containers in the pod have terminated in success, and will not be restarted.
  // Failed: All containers in the pod have terminated, and at least one container has

- kubelet: Users can now enable the alpha NodeLease feature gate to have the Kubelet create and periodically renew a Lease in the kube-node-lease namespace. The lease duration defaults to 40s, and can be configured via the kubelet.config.k8s.io/v1beta1.KubeletConfiguration's NodeLeaseDurationSeconds field. ([#66257](https://github.com/kubernetes/kubernetes/pull/66257), [@mtaufen](https://github.com/mtaufen))...

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...

- 'Promoted the `APIServerIdentity` feature to Beta. By default, each `kube-apiserver`
  will now create a Lease in the `kube-system` namespace. These lease objects can
  be used to identify the number of active API servers in the cluster, and may also
  be used for future features such as the Storage Version API.'

* kube-apiserver: the default `--endpoint-reconciler-type` is now `lease`. The `master-count` endpoint reconciler type is deprecated and will be removed in 1.13. ([#63383](https://github.com/kubernetes/kubernetes/pull/63383), [@liggitt](https://github.com/liggitt))