- Updated `kubeadm` to use the `InitialCorruptCheck=true` etcd feature gate instead of the deprecated `--experimental-initial-corrupt-check` flag. Also replaced the use of `--experimental-watch-progress-notify-interval` with its graduated counterpart `--watch-progress-notify-interval`. ([#132838](https://github.com/kubernetes/kubernetes/pull/132838), [@AwesomePatrol](https://github.com/AwesomePatrol))

- `--sync-frequency` will not affect the update interval of volumes that use `ConfigMaps`
  or `Secrets` when the `configMapAndSecretChangeDetectionStrategy` is set to `Cache`.

- Promote WatchBookmark feature to beta and enable it by default.
  With WatchBookmark feature, clients are able to request watch events with BOOKMARK type. Clients should not assume bookmarks are returned at any specific interval, nor may they assume the server will send any BOOKMARK event during a session. ([#79786](https://github.com/kubernetes/kubernetes/pull/79786), [@wojtek-t](https://github.com/wojtek-t))

*   `kube-apiserver` now runs with the default value for `service-cluster-ip-range` ([#52870](https://github.com/kubernetes/kubernetes/pull/52870),[ @jennybuckley](https://github.com/jennybuckley))
*   Add `--etcd-compaction-interval` to apiserver for controlling request of compaction to etcd3 from apiserver. ([#51765](https://github.com/kubernetes/kubernetes/pull/51765),[ @mitake](https://github.com/mitake))

## New Features

- kubelet: When node lease feature is enabled, kubelet reports node status to api server only if there is some change or it didn't report over last report interval. ([#69753](https://github.com/kubernetes/kubernetes/pull/69753), [@wangzhen127](https://github.com/wangzhen127))

* fix azure disk attachment error on Linux ([#70002](https://github.com/kubernetes/kubernetes/pull/70002), [@andyzhangx](https://github.com/andyzhangx))
* GCE/GKE load balancer health check default interval changes from 2 seconds to 8 seconds, unhealthyThreshold to 3. ([#70099](https://github.com/kubernetes/kubernetes/pull/70099), [@grayluck](https://github.com/grayluck))

- Potentially breaking change - Updating the polling interval for Windows stats collection from 1 second to 10 seconds ([#116546](https://github.com/kubernetes/kubernetes/pull/116546), [@marosset](https://github.com/marosset)) [SIG Node and Windows]

- Kubeadm: enabled the --experimental-watch-progress-notify-interval flag for etcd and set it to 5s. The flag specifies an interval at which etcd sends watch data to the kube-apiserver. ([#111383](https://github.com/kubernetes/kubernetes/pull/111383), [@p0lyn0mial](https://github.com/p0lyn0mial))

- 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]

* Corrects check for non-Azure managed nodes with the Azure cloud provider ([#70135](https://github.com/kubernetes/kubernetes/pull/70135), [@marc-sensenich](https://github.com/marc-sensenich))
* GCE/GKE load balancer health check default interval changes from 2 seconds to 8 seconds, unhealthyThreshold to 3. ([#70099](https://github.com/kubernetes/kubernetes/pull/70099), [@grayluck](https://github.com/grayluck))