- Add --permit-address-sharing flag to `kube-apiserver` to listen with `SO_REUSEADDR`. While allowing to listen on wildcard IPs like 0.0.0.0 and specific IPs in parallel, it avoids waiting for the kernel to release socket in `TIME_WAIT` state, and hence, considerably reducing `kube-apiserver` restart times under certain conditions. ([#93861](https://github.com/kubernetes/kubernetes/pull/93861), [@sttts](https://github.com/sttts))

- Promoted the following apiserver flowcontrol metrics to Beta:

  - apiserver_flowcontrol_request_wait_duration_seconds 
  - apiserver_flowcontrol_current_executing_seats
  - apiserver_flowcontrol_nominal_limit_seats
  - apiserver_flowcontrol_rejected_requests_total
  - apiserver_flowcontrol_dispatched_requests_total

- The `wait.Poll*` and `wait.ExponentialBackoff*` functions have been deprecated and will be removed in a future release.  Callers should switch to using `wait.PollUntilContextCancel`, `wait.PollUntilContextTimeout`, or `wait.ExponentialBackoffWithContext` as appropriate.
  

* kubectl port-forward now allows using resource name (e.g., deployment/www) to select a matching pod, as well as the use of --pod-running-timeout to wait until at least one pod is running. ([#59705](https://github.com/kubernetes/kubernetes/pull/59705), [@phsiao](https://github.com/phsiao))

- Add `plugin_execution_duration_seconds` metric for scheduler framework plugins. ([#84522](https://github.com/kubernetes/kubernetes/pull/84522), [@liu-cong](https://github.com/liu-cong))
- Add `permit_wait_duration_seconds` metric to the scheduler. ([#84011](https://github.com/kubernetes/kubernetes/pull/84011), [@liu-cong](https://github.com/liu-cong))

### Deprecated/changed metrics

* Fix the bug where kubelet in the standalone mode would wait for the update from the apiserver source. ([#59276](https://github.com/kubernetes/kubernetes/pull/59276), [@roboll](https://github.com/roboll))

- `kubectl create {clusterrole,role}`'s `--resources` flag now supports asterisk to specify all resources. ([#62945](https://github.com/kubernetes/kubernetes/pull/62945), [@nak3](https://github.com/nak3))
- kubectl: the wait command now prints an error message and exits with the code 1, if there is no resources matching selectors ([#66692](https://github.com/kubernetes/kubernetes/pull/66692), [@m1kola](https://github.com/m1kola))

 - Fix: support removal of nodes backed by deleted non VMSS instances on Azure ([#91184](https://github.com/kubernetes/kubernetes/pull/91184), [@bpineau](https://github.com/bpineau)) [SIG Cloud Provider]
 - Fixed a 1.18 regression in wait.Forever that skips the backoff period on the first repeat ([#90476](https://github.com/kubernetes/kubernetes/pull/90476), [@zhan849](https://github.com/zhan849)) [SIG API Machinery]

For more information and for updates on resolution of this issue, see [#51899](https://github.com/kubernetes/kubernetes/issues/51899).

* Scale max-inflight limits together with master VM sizes. ([#73268](https://github.com/kubernetes/kubernetes/pull/73268), [@wojtek-t](https://github.com/wojtek-t))
* kubeadm: explicitly wait for `etcd` to have grown when joining a new control plane ([#72984](https://github.com/kubernetes/kubernetes/pull/72984), [@ereslibre](https://github.com/ereslibre))