- Updated...

- Fix: ignore non-VMSS error for VMAS nodes in `reconcileBackendPools`. ([#103997](https://github.com/kubernetes/kubernetes/pull/103997), [@nilo19](https://github.com/nilo19))
- Fix: leave the probe path empty for TCP probes ([#105253](https://github.com/kubernetes/kubernetes/pull/105253), [@nilo19](https://github.com/nilo19))

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...

- In "large" clusters, kube-proxy in iptables mode will now sometimes
  leave unused rules in iptables for a while (up to `--iptables-sync-period`)
  before deleting them. This improves performance by not requiring it to
  check for stale rules on every sync. (In smaller clusters, it will still

### 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]

- Promote NodeLease feature to GA.

- 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))

- '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.'

- 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))...