- Deprecate the instance type beta label (`beta.kubernetes.io/instance-type`) in favor of its GA equivalent: `node.kubernetes.io/instance-type` ([#82049](https://github.com/kubernetes/kubernetes/pull/82049), [@andrewsykim](https://github.com/andrewsykim))

    - `scheduler_async_api_call_execution_total`: tracks executed API calls by call type and result (success/error)
    - `scheduler_async_api_call_duration_seconds`: histogram of API call execution duration by call type and result

Also, please note:
- using `application/vnd.kubernetes.protobuf` as the media storage type for 1.6 is default but not required
- the ability to rollback to etcd2 can be preserved by setting the storage media type flag on `kube-apiserver`

  ```
  --storage-media-type application/json
  ```

  to continue to use `application/json` as the storage media type which can be changed to
  `application/vnd.kubernetes.protobuf` at a later time.

([#46669](https://github.com/kubernetes/kubernetes/pull/46669), [@kow3ns](https://github.com/kow3ns)).

* ControllerRevision type has been added for StatefulSet and DaemonSet history. Clients should not depend on the stability of this type as it may change, as necessary, in future releases to support StatefulSet and DaemonSet update and rollback. We enable this type as we do with beta features, because StatefulSet update and DaemonSet update are enabled. ([#45867](https://github.com/kubernete...

- Resolves a spurious "Unknown discovery response content-type" error in client-go discovery requests by tolerating extra content-type parameters in API responses ([#117637](https://github.com/kubernetes/kubernetes/pull/117637), [@seans3](https://github.com/seans3)) [SIG API Machinery]

  ```sh
  $ kubectl get event
  LAST SEEN   TYPE     REASON              OBJECT                        MESSAGE
  <unknown>   Normal   Scheduled           pod/nginx-6c975b59f8-gvmjr    Successfully assigned default/nginx-6c975b59f8-gvmjr to minikube
  
  $ kubectl describe pod xxx
  ......
  Events:
    Type    Reason     Age        From               Message

   ([#123611](https://github.com/kubernetes/kubernetes/pull/123611), [@ritazh](https://github.com/ritazh))

    * If the serialization type is application/vnd.kubernetes.protobuf, and protobuf marshaling is not implemented for the requested API resource type, a '406 Not Acceptable is returned'.
    * If the serialization type is 'application/json':

    * master subnet.  It is ignored if the service is not on Azure, if the type is not
    * LoadBalancer, or if the load balancer is not internal.
* Adds a command-line argument to kube-apiserver called ([#51698](https://github.com/kubernetes/kubernetes/pull/51698), [@rphillips](https://github.com/rphillips))
    * --alpha-endpoint-reconciler-type=(master-count, lease, none) (default

- Removed attachable volume limits from the capacity of the node for the following
  volume type when the kubelet was started, affecting the following volume types
  when the corresponding csi driver was installed:
  - `awsElasticBlockStore` for `ebs.csi.aws.com`
  - `azureDisk` for `disk.csi.azure.com`