* Change eviction policies in NodeController:
      *  add a "partialDisruption" mode, when more than 33% of Nodes in the zone are not Ready
      *  add "fullDisruption" mode, when all Nodes in the zone are not Ready
    * Eviction behavior depends on the mode in which NodeController is operating:

## Changelog since v1.15.7

### Other notable changes

* Fixed a regression where the kubelet would fail to update the ready status of pods. ([#86195](https://github.com/kubernetes/kubernetes/pull/86195), [@tedyu](https://github.com/tedyu))

the new apiVersion will still be accessible, using the old version.   You can
continue to use your existing JSON and YAML files until you are ready to switch
to <code>batch/v1</code>.  We may remove support for Jobs with  <code>apiVersion: extensions/v1beta1 </code>in 1.3 or 1.4.
  *  HorizontalPodAutoscaler was Beta in 1.1 and is GA in 1.2 .

    * setting `ENABLE_METADATA_CONCEALMENT=true` in kube-up will now set a `cloud.google.com/metadata-proxy-ready=true` label on new nodes. In v1.16, the metadata proxy add-on will switch to using that label as a node selector.
    * setting `KUBE_PROXY_DAEMONSET=true` in kube-up will now set a `node.kubernetes.io/kube-proxy-ds-ready=true` label on new nodes. In v1.16, the kube-proxy daemonset add-on will switch to using that label as a node selector.

* remove time waiting after create storage account (save 25s) ([#56679](https://github.com/kubernetes/kubernetes/pull/56679), [@andyzhangx](https://github.com/andyzhangx))
* Allow kubernetes components to react to SIGTERM signal and shutdown gracefully. ([#57756](https://github.com/kubernetes/kubernetes/pull/57756), [@mborsz](https://github.com/mborsz))

* NodeController doesn't evict Pods if no Nodes are Ready ([#25571](https://github.com/kubernetes/kubernetes/pull/25571), [@gmarek](https://github.com/gmarek))

  When the `PDBUnhealthyPodEvictionPolicy` feature-gate is enabled in `kube-apiserver`,
  setting this field to `"AlwaysAllow"` allows pods to be evicted if they do not
  have a ready condition, regardless of whether the PodDisruptionBudget is currently
  healthy.'
   ([#113375](https://github.com/kubernetes/kubernetes/pull/113375), [@atiratree](https://github.com/atiratree))

- Fixed the API comments for the Job `Ready` field in status. ([#121765](https://github.com/kubernetes/kubernetes/pull/121765), [@mimowo](https://github.com/mimowo))