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

- DaemonSets accept a MaxSurge integer or percent on their rolling update strategy that will launch the updated pod on nodes and wait for those pods to go ready before marking the old out-of-date pods as deleted. This allows workloads to avoid downtime during upgrades when deployed using DaemonSets. This feature...

implementation of RFC-3986, have duplicate "/" removed from the URL paths, and passed like that directly to the `kube-apiserver` `--etcd-servers` flag. If you have etcd endpoints that have Unicode characters, it is advisable to encode them in advance with tooling that is fully IDNA compliant. If you don't do that, the Go standard library (used in k8s and etcd) would do it for you when making requests to the endpoints. ([#103801](https://github.com/kubernetes/kubernetes/pull/103801), [@gkarthiks](https://g...

### 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

* fix: azure disk could not mounted on Standard_DC4s/DC2s instances ([#86612](https://github.com/kubernetes/kubernetes/pull/86612), [@andyzhangx](https://github.com/andyzhangx))
* Fix v1.17.0 regression in reflector relist causing master rolling upgrade to fail for large clusters due to excessive list calls to etcd ([#86824](https://github.com/kubernetes/kubernetes/pull/86824), [@jpbetz](https://github.com/jpbetz))

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

    * `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

- Added consistent vanity import to files and provided tooling for verifying and updating them. ([#120642](https://github.com/kubernetes/kubernetes/pull/120642), [@jcchavezs](https://github.com/jcchavezs))

### SIG-cli

SIG CLI focused on implementing the new plugin mechanism, providing a library with common CLI tooling for plugin authors and further refactorings of the code.

### SIG-cloud-provider

    * If your config files contains fields with wrong case, the config files will be now invalid.
* GCE: Fixes operation polling to adhere to the specified interval. Furthermore, operation errors are now returned instead of ignored. ([#64630](https://github.com/kubernetes/kubernetes/pull/64630), [@nicksardo](https://github.com/nicksardo))