*   Added warmup capabilities to `tf.keras.optimizers.schedules.CosineDecay` learning rate scheduler. You can now specify an initial and target learning rate, and our scheduler will perform a linear interpolation between the two after which it will begin a decay phase.

* Separate current ARM rate limiter into read/write ([#59830](https://github.com/kubernetes/kubernetes/pull/59830), [@khenidak](https://github.com/khenidak))

   *
   * The Least Recently Used page replacement algorithm was chosen due to its simplicity, high hit
   * rate, and ability to be implemented with O(1) time complexity. The initial LRU implementation
   * operates per-segment rather than globally for increased implementation simplicity. We expect
   * the cache hit rate to be similar to that of a global LRU algorithm.
   */

  // Constants

  /**

- Apiserver `/healthz/etcd` endpoint rate limits the number of forwarded health check requests to the etcd backends, answering with the last known state if the rate limit is exceeded. The rate limit is based on 1/2 of the timeout configured, with no burst allowed. ([#112046](https://github.com/kubernetes/kubernetes/pull/112046), [@aojea](https://github.com/aojea))...

* Pass cluster_location argument to Heapster ([#65176](https://github.com/kubernetes/kubernetes/pull/65176), [@kawych](https://github.com/kawych))
* Fix a scalability issue where high rates of event writes degraded etcd performance. ([#64539](https://github.com/kubernetes/kubernetes/pull/64539), [@ccding](https://github.com/ccding))

* Fix a scalability issue where high rates of event writes degraded etcd performance. ([#64539](https://github.com/kubernetes/kubernetes/pull/64539), [@ccding](https://github.com/ccding))

* Refactor to simplify the hard-traveled path of the KubeletConfiguration object ([#29216](https://github.com/kubernetes/kubernetes/pull/29216), [@mtaufen](https://github.com/mtaufen))
* Fix overflow issue in controller-manager rate limiter ([#31396](https://github.com/kubernetes/kubernetes/pull/31396), [@foxish](https://github.com/foxish))

Please see the [Releases Page](https://github.com/kubernetes/kubernetes/releases) for older releases.

A security issue was discovered in Kubernetes that could allow  Windows workloads to run as `ContainerAdministrator` even when those workloads set the `runAsNonRoot` option to `true `.

This issue has been rated low and assigned CVE-2021-25749

### Am I vulnerable?

All Kubernetes clusters with following versions, running Windows workloads with `runAsNonRoot` are impacted

#### Affected Versions

* Fix a scalability issue where high rates of event writes degraded etcd performance. ([#64539](https://github.com/kubernetes/kubernetes/pull/64539), [@ccding](https://github.com/ccding))

- Fixed a bug that caused a DaemonSet rolling update to hang when its pod gets stuck at terminating.  ([#77773](https://github.com/kubernetes/kubernetes/pull/77773), [@DaiHao](https://github.com/DaiHao))
- Route controller now respects rate limiting to the cloud provider on deletion; previously it was only for create. ([#78581](https://github.com/kubernetes/kubernetes/pull/78581), [@andrewsykim](https://github.com/andrewsykim))