## Urgent Upgrade Notes

### (No, really, you MUST read this before you upgrade)

#### Cluster Lifecycle

- Container images tar files for `amd64` will now contain the architecture in the RepoTags manifest.json section.
  If you are using docker manifests there are not visible changes. ([#80266](https://github.com/kubernetes/kubernetes/pull/80266), [@javier-b-perez](https://github.com/javier-b-perez))

Shim for \"new\" HTML5 structural elements to display correctly (IE10, older browsers)\n// TODO: remove in v5\n// stylelint-disable-next-line selector-list-comma-newline-after\narticle, aside, figcaption, figure, footer, header, hgroup, main, nav, section {\n  display: block;\n}\n\n// Body\n//\n// 1. Remove the margin in all browsers.\n// 2. As a best practice, apply a default `background-color`.\n// 3. Set an explicit initial text-align value so that we can later use\n//    the `inherit` value on...

- Added support for RSA and ECDSA format keys in preflight check on `kubeadm`. ([#112508](https://github.com/kubernetes/kubernetes/pull/112508), [@SataQiu](https://github.com/SataQiu))
- Allowed `Label` section in vSphere e2e cloud provider configuration. ([#112427](https://github.com/kubernetes/kubernetes/pull/112427), [@gnufied](https://github.com/gnufied))

- Client-go: Optimized leaders renewing leases by updating leader lock optimistically without getting the record from the API server first. Also, a new metric `leader_election_slowpath_total` was added to allow users to monitor how many leader elections are updated non-optimistically.
   ([#122069](https://github.com/kubernetes/kubernetes/pull/122069), [@linxiulei](https://github.com/linxiulei))
- Locked the GA feature-gate `ConsistentHTTPGetHandlers` to default.

- Reduce critical section in watchcache to fix kube-apiserver scalability under heavy load of list requests ([#122027](https://github.com/kubernetes/kubernetes/pull/122027), [@wojtek-t](https://github.com/wojtek-t)) [SIG API Machinery]

## Dependencies

Mono","Courier New",monospace}*,::after,::before{box-sizing:border-box}html{font-family:sans-serif;line-height:1.15;-webkit-text-size-adjust:100%;-webkit-tap-highlight-color:transparent}article,aside,figcaption,figure,footer,header,hgroup,main,nav,section{display:block}body{margin:0;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Helvetica Neue",Arial,"Noto Sans",sans-serif,"Apple Color Emoji","Segoe UI Emoji","Segoe UI Symbol","Noto Color Emoji";font-size:1rem;font-weight:400;line...

- Kubeadm: Switched kubeadm to start using the CRI client library instead of shelling out of the `crictl` binary
  for actions against a CRI endpoint. The kubeadm deb/rpm packages will continue to install the `cri-tools`
  package for one more release, but in you must adapt your scripts to install `crictl` manually from

Mono","Courier New",monospace}*,::after,::before{box-sizing:border-box}html{font-family:sans-serif;line-height:1.15;-webkit-text-size-adjust:100%;-webkit-tap-highlight-color:transparent}article,aside,figcaption,figure,footer,header,hgroup,main,nav,section{display:block}body{margin:0;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Helvetica Neue",Arial,"Noto Sans","Liberation Sans",sans-serif,"Apple Color Emoji","Segoe UI Emoji","Segoe UI Symbol","Noto Color Emoji";font-size:1rem;fo...

func (c *SiteReplicationSys) newConcErr(errMap map[string]error, actionName string) error {
	return concErr{
		errMap:     errMap,
		summaryErr: c.toErrorFromErrMap(errMap, actionName),
	}
}

// concDo calls actions concurrently. selfActionFn is run for the current
// cluster and peerActionFn is run for each peer replication cluster.

                items:
                  properties:
                    audiences:
                      description: The list of JWT [audiences](https://tools.ietf.org/html/rfc7519#section-4.1.3)
                        that are allowed to access.
                      items:
                        minLength: 1
                        type: string
                      type: array