- For metrics `apiserver_cache_list_fetched_objects_total`, `apiserver_cache_list_returned_objects_total`, `apiserver_cache_list_total` replace `resource_prefix` label with API `group` and `resource` labels.
  For metrics `etcd_request_duration_seconds`, `etcd_requests_total` and `etcd_request_errors_total` replace `type` label with API `resource` and `group` label.
  For metric `apiserver_selfrequest_total` add a API `group` label.

### API Change

 - The default spec.updateStrategy for the StatefulSet and DaemonSet kinds is
 RollingUpdate for the apps/v1beta2 group version. You can explicitly set
 the OnDelete strategy, and no strategy auto-conversion is applied to
 replace default values.

 - As mentioned in [Behavioral Changes](#behavioral-changes), selector
 defaults are disabled.

 - The default spec.revisionHistoryLimit for all applicable kinds in the

- kube-controller-manager now uses the informer cache instead of active pod gets in HPA controller ([#68241](https://github.com/kubernetes/kubernetes/pull/68241), [@krzysztof-jastrzebski](https://github.com/krzysztof-jastrzebski))

- Fixes a regression in v1beta1 PodDisruptionBudget handling of `strategic merge patch`-type API requests for the `selector` field. Prior to 1.21, these requests would merge `matchLabels` content and replace `matchExpressions` content. In 1.21, patch requests touching the `selector` field started replacing the entire selector. This is consistent with server-side apply and the v1 PodDisruptionBudget behavior, but should not have been changed for v1beta1....

### API Change

* Remove DirectCodecFactory(replace with serializer.WithoutConversionCodecFactory), DirectEncoder(replace with runtime.WithVersionEncoder) and DirectDecoder(replace with runtime.WithoutVersionDecoder). action required ([#79263](https://github.com/kubernetes/kubernetes/pull/79263), [@draveness](https://github.com/draveness))

release is the work on moving internal APIs that the vSphere provider depends upon to staging to guarantee API stability. This work is being done in conjunction with SIG Cloud Provider and includes the creation of a brand new vsphere-csi plugin to replace the current volume functionalities in-tree.

Additional work was also done to implement a vSphere provider for the Cluster API effort lead by SIG Cluster Lifecycle. For the out-of-tree vSphere cloud provider, the SIG largely focused on...

  * To update a controller's PodSpec to use the field instead of the annotation, use one of the kubectl commands that do update ("kubectl replace" or "kubectl apply" or "kubectl patch") or just delete the controller entirely and re-create it with a new pod template. Note that you will be able to do these things only after the upgrade.

### Service

* Fix multi-attach error spam in logs and events ([#53401](https://github.com/kubernetes/kubernetes/pull/53401), [@gnufied](https://github.com/gnufied))
* Use `not-ready` to replace `notReady` in node condition taint keys. ([#51266](https://github.com/kubernetes/kubernetes/pull/51266), [@resouer](https://github.com/resouer))