* `kubectl rollout undo` no longer uses the deprecated extensions/v1beta1 rollback API, which means that Events are no longer emitted when rolling back a deployment

  - [stable] `kubectl apply` is now able to delete resources you no longer need with `--prune` ([kubernetes/features#128](https://github.com/kubernetes/enhancements/issues/128))
  - [beta] Deployments that cannot make progress in rolling out the newest version will now indicate via the API they are blocked ([docs](http://kubernetes.io/docs/user-guide/deployments/#failed-deployment)) ([kubernetes/features#122](https://github.com/kubernetes/enhancements/issues/122))

- Revised the logic for DaemonSet rolling update to exclude nodes if scheduling constraints are not met.

### Apps

- Fix a bug that pods not be deleted from unmatched nodes by daemon controller ([#78974](https://github.com/kubernetes/kubernetes/pull/78974), [@DaiHao](https://github.com/DaiHao))
- Fix a bug that causes DaemonSet rolling update hang when there exist failed pods. ([#78170](https://github.com/kubernetes/kubernetes/pull/78170), [@DaiHao](https://github.com/DaiHao))

### Auth

An alternative implementation of the `CronJob` controller is now available as an alpha feature in this release, which has experimental performance improvement by using informers instead of polling. While this will be the default behavior in the future, you can [try them in this release through a feature gate](https://docs.k8s.io/concepts/workloads/controllers/cron-jobs/).

### PID Limits graduates to General Availability

- Removes the deprecated command `kubectl rolling-update` ([#88057](https://github.com/kubernetes/kubernetes/pull/88057), [@julianvmodesto](https://github.com/julianvmodesto)) [SIG Architecture, CLI and Testing]

### kubectl rolling-update: < v1.4.0 client vs >=v1.4.0 cluster

Old version kubectl's rolling-update command is compatible with Kubernetes 1.4 and higher only if you specify a new replication controller name. You will need to update to kubectl 1.4 or higher to use the rolling update command against a 1.4 cluster if you want to keep the original name, or you'll have to do two rolling updates.

### DaemonSet
* **[beta]** Introduce the rolling update feature for DaemonSet. See [Performing a Rolling Update on a DaemonSet](https://kubernetes.io/docs/tasks/manage-daemon/update-daemon-set/).

### Deployment

- Created a new `kubectl rollout restart` command that does a rolling restart of a deployment. ([#76062](https://github.com/kubernetes/kubernetes/pull/76062), [@apelisse](https://github.com/apelisse))

defines the number of nodes that if not Ready in time won’t cause kube-up
failure.
  * “kubectl rolling-update” only supports Replication Controllers (it doesn’t
support Replica Sets). It’s recommended to use Deployment 1.2 with “kubectl
rollout” commands instead, if you want to rolling update Replica Sets.
  * When live upgrading Kubelet to 1.2 without draining the pods running on the node,