- Kube-apiserver: ensures the namespace of objects sent to admission webhooks matches the request namespace. Previously, objects without a namespace set would have the request namespace populated after mutating admission, and objects with a namespace that did not match the request namespace would be rejected after admission. ([#94...

- The deprecated flag --experimental-kustomize is now removed from kubeadm commands. Use --experimental-patches instead, which was introduced in 1.19. Migration information available in --help description for --experimental-patches. ([#94871](https://github.com/kubernetes/kubernetes/pull/94871), [@neolit123](https://github.com/neolit123))

- Add scheduling support for RuntimeClasses. RuntimeClasses can now specify nodeSelector...

- `apiserver_dropped_requests` is dropped from this release since `apiserver_request_total` can now be used to track dropped requests. `etcd_object_counts` is also removed in favor of `apiserver_storage_objects`. `apiserver_registered_watchers` is also removed in favor of `apiserver_longrunning_requests`. ([#110337](https://github.com/kubernetes/kubernetes/pull/110337), [@logicalhan](https://github.com/logicalhan))

 - The flag `--experimental-patches` is now deprecated and will be removed in a future release. You can migrate to using the new flag `--patches`. Add a new field `{Init|Join}Configuration.patches.directory` that can be used for the same purpose. For `init` and `join` it is now recommended that you migrate to configure patches via `{Init|Join}Configuration.patches.directory`. For the time being, these flags can be mixed with `--config`, but that...

- Azurefile: Normalize share name to not include capital letters ([#100731](https://github.com/kubernetes/kubernetes/pull/100731), [@kassarl](https://github.com/kassarl)) [SIG Cloud Provider and Storage]
- EndpointSlice IP validation now matches Endpoints IP validation. ([#101084](https://github.com/kubernetes/kubernetes/pull/101084), [@robscott](https://github.com/robscott)) [SIG Apps and Network]

- Kube-scheduler now retries scheduling Pods rejected by the PodTopologySpread plugin when related Pods are created, deleted, updated, or when a node matches the specified topologyKey. ([#122195](https://github.com/k...

- Added `objectSelector` to admission webhook configurations. `objectSelector` is evaluated the oldObject and newObject that would be sent to the webhook, and is considered to match if either object matches the selector. A null object (oldObject in the case of create, or newObject in the case of delete) or an object that cannot have labels (like a DeploymentRollback or a PodProxyOptions object) is not considered to match. Use the object selector only...

* etcd3: watcher logging error ([#32831](https://github.com/kubernetes/kubernetes/pull/32831), [@hongchaodeng](https://github.com/hongchaodeng))
* etcd: watcher centralize error handling ([#32907](https://github.com/kubernetes/kubernetes/pull/32907), [@hongchaodeng](https://github.com/hongchaodeng))

  * Mediates issue [#36859](https://github.com/kubernetes/kubernetes/pull/36859). StatefulSet only acts on Pods whose identity matches the StatefulSet, providing a partial mediation for overlapping controllers.

### Taints and Tolerations