* Add the support to the scheduler for spreading pods of StatefulSets. ([#41708](https://github.com/kubernetes/kubernetes/pull/41708), [@bsalamat](https://github.com/bsalamat))
* Added support to minimize sending verbose node information to scheduler extender by sending only node names and expecting extenders to cache the rest of the node information ([#41119](https://github.com/kubernetes/kubernetes/pull/41119), [@sarat-k](https://github.com/sarat-k))

* Fix public IP not found issues for VMSS nodes ([#80703](https://github.com/kubernetes/kubernetes/pull/80703), [@feiskyer](https://github.com/feiskyer))
* Resolves a bug that prevented sending a multi-version custom resource to an admission webhook. ([#79495](https://github.com/kubernetes/kubernetes/pull/79495), [@liggitt](https://github.com/liggitt))

## Changelog since v1.16.9

## Changes by Kind

### API Change
 - Fix bug where sending a status update completely wipes managedFields for some types. ([#90033](https://github.com/kubernetes/kubernetes/pull/90033), [@apelisse](https://github.com/apelisse)) [SIG API Machinery and Testing]

### Bug or Regression

- Duplicate owner reference entries in create/update/patch requests now get deduplicated by the API server. The client sending the request now receives a warning header in the API response. Clients should stop sending requests with duplicate owner references. The API server may reject such requests as early as 1.24. ([#96185](https://github.com/kubernetes/kubernetes/pull/96185), [@roycaihw](https://github.com/roycaihw))...

</p>

<h3 id="Channel_types">Channel types</h3>

<p>
A channel provides a mechanism for
<a href="#Go_statements">concurrently executing functions</a>
to communicate by
<a href="#Send_statements">sending</a> and
<a href="#Receive_operator">receiving</a>
values of a specified element type.
The value of an uninitialized channel is <code>nil</code>.
</p>

<pre class="ebnf">

*   Webhooks now always retry sending if a connection reset error is returned. ([#53947](https://github.com/kubernetes/kubernetes/pull/53947),[ @crassirostris](https://github.com/crassirostris))

#### **Custom Resources**

- In clusters where the DryRun feature is enabled,...

  // routing to all endpoints evenly (possibly modified by topology and other
  // features). Note that traffic sent to an External IP or LoadBalancer IP from
  // within the cluster will always get "Cluster" semantics, but clients sending to
  // a NodePort from within the cluster may need to take traffic policy into account
  // when picking a node.
  // +optional
  optional string externalTrafficPolicy = 11;

## Changelog since v1.17.5

## Changes by Kind

### API Change
 - Fix bug where sending a status update completely wipes managedFields for some types. ([#90032](https://github.com/kubernetes/kubernetes/pull/90032), [@apelisse](https://github.com/apelisse)) [SIG API Machinery and Testing]

### Bug or Regression

* Fixes an issue with upgrade requests made via pod/service/node proxy subresources sending a non-absolute HTTP request-uri to backends ([#52065](https://github.com/kubernetes/kubernetes/pull/52065), [@liggitt](https://github.com/liggitt))