* validation schemata as an alpha feature, to be enabled via the "CustomResourcePublishOpenAPI" feature gate. Kubectl will validate client-side using those. Note that in
    * future, client-side validation in 1.14 kubectl against a 1.15 cluster will reject
    * unknown fields for CRDs with validation schema defined. 

- Added `client-go` support for upgrading subresource fields from client-side to server-side management. ([#123484](https://github.com/kubernetes/kubernetes/pull/123484), [@erikgb](https://github.com/erikgb))

- The server-side apply feature is now beta ([#81956](https://github.com/kubernetes/kubernetes/pull/81956), [@apelisse](https://github.com/apelisse))

* fix mixed protocol issue for azure load balancer ([#74200](https://github.com/kubernetes/kubernetes/pull/74200), [@andyzhangx](https://github.com/andyzhangx))
* fix issue: fail to detach azure disk when there is server side error ([#74398](https://github.com/kubernetes/kubernetes/pull/74398), [@andyzhangx](https://github.com/andyzhangx))

### SIG CLI

- For `kubectl`, `--server-side` now migrates ownership of all fields used by client-side-apply to the specified `--fieldmanager`. This prevents fields previously specified using kubectl from being able to live outside of server-side-apply's management and become undeleteable. ([#112905](https://github.com/kubernetes/kubernetes/pull/112905), [@alexzielenski](https://github.com/alexzielenski))...

[Sig API Machinery]: https://github.com/kubernetes/community/tree/master/sig-api-machinery

### SIG Apps

  - [beta] `kube-apiserver` now publishes a swagger 2.0 spec in addition to a swagger 1.2 spec ([kubernetes/features#53](https://github.com/kubernetes/enhancements/issues/53))
  - [beta] Server-side garbage collection is enabled by default. See [user-guide](http://kubernetes.io/docs/user-guide/garbage-collection/)
- **Apps**

    * handle gracefully problem when kubelet reports duplicated stats for the same container (see [#47853](https://github.com/kubernetes/kubernetes/pull/47853)) on Heapster side
    * fixed bugs and improved performance in Stackdriver Sink

- Fixed an issue that allowed Custom Resources to be created using Server-Side Apply even when their `CustomResourceDefinition` was terminating. ([#132467](https://github.com/kubernetes/kubernetes/pull/132467), [@sdowell](https://github.com/sdowell))