// The global minimum is the minimum number of matching pods in an eligible domain
  // or zero if the number of eligible domains is less than MinDomains.
  // For example, in a 3-zone cluster, MaxSkew is set to 1, and pods with the same
  // labelSelector spread as 2/2/1:
  // In this case, the global minimum is 1.
  // +-------+-------+-------+

* In-place node upgrades to this release from versions 1.7.14, 1.8.9, and 1.9.4 are not supported if using subpath volumes with PVCs.  Such pods should be drained from the node first.

* The minimum supported version of Docker is now 1.11; if you are using Docker 1.10 or below, be sure to upgrade Docker before upgrading Kubernetes. ([#57845](https://github.com/kubernetes/kubernetes/pull/57845), [@yujuhong](https://github.com/yujuhong))

- The resource version option, when passed to a list call, is now consistently interpreted as the minimum allowed resource version.  Previously when listing resources that had the watch cache disabled clients could retrieve a snapshot at that exact resource version.  If the client requests a resource version newer than the current state, a TimeoutError...

  
  vSphere releases less than 67u3 are deprecated as of v1.21. Please consider upgrading vSphere to 67u3 or above. vSphere CSI Driver requires minimum vSphere 67u3.
  
  VM Hardware version less than 15 is deprecated as of v1.21. Please consider upgrading the Node VM Hardware version to 15 or above. vSphere CSI Driver recommends Node VM's Hardware version set to at least vmx-15.

* The global flag "context" now gets applied to `kubectl config view --minify`. In previous versions, this command was only available for `current-context`. Now it will be easier for users to view other non current contexts when minifying. ([#64608](https://github.com/kubernetes/kubernetes/pull/64608), [@dixudx](https://github.com/dixudx))...

### Network

- Reduces the cache TTL for negative responses to 5s minimum. ([#74093](https://github.com/kubernetes/kubernetes/pull/74093), [@blakebarnett](https://github.com/blakebarnett))

### Node

*   The Go version was upgraded from go1.8.3 to **go1.9.2** ([#51375](https://github.com/kubernetes/kubernetes/pull/51375),[ @cblecker](https://github.com/cblecker))
    *   The minimum supported go version bumps to 1.9.1. ([#55301](https://github.com/kubernetes/kubernetes/pull/55301),[ @xiangpengzhao](https://github.com/xiangpengzhao))

language.
</p>

<p>
A link of the form [<a href="#Language_versions">Go 1.xx</a>] indicates that a described
language feature (or some aspect of it) was changed or added with language version 1.xx and
thus requires at minimum that language version to build.
For details, see the <a href="#Language_versions">linked section</a>
in the <a href="#Appendix">appendix</a>.
</p>

<h2 id="Source_code_representation">Source code representation</h2>

- Images for cloud-controller-manager, kube-apiserver, kube-controller-manager, and kube-scheduler now contain a minimal /etc/nsswitch.conf and should respect /etc/hosts for lookups ([#69238](https://github.com/kubernetes/kubernetes/pull/69238), [@BenTheElder](https://github.com/BenTheElder))

### SIG Scheduling

Agreement is invalid or unenforceable under applicable law, it shall not affect the validity or enforceability of the remainder of the terms of this Agreement, and without further action by the parties hereto, such provision shall be reformed to the minimum extent necessary to make such provision valid and enforceable. If Recipient institutes patent litigation against any entity (including a cross-claim or counterclaim in a lawsuit) alleging that the Program itself (excluding combinations of the Program...