- `kubeadm`: improved the logic that checks whether a `systemd` service exists. ([#120514](https://github.com/kubernetes/kubernetes/pull/120514), [@fengxsong](https://github.com/fengxsong))
- `kubeadm`: will now use universal deserializer to decode static pod. ([#120549](https://github.com/kubernetes/kubernetes/pull/120549), [@pacoxu](https://github.com/pacoxu))
- `kubectl prune v2`: Switched annotation from `contains-group-resources` to `contains-group-kinds`,

- Zero-value `metadata.creationTimestamp` values are now omitted and no longer serialize an explicit `null` in JSON, YAML, and CBOR output ([#130989](https://github.com/kubernetes/kubernetes/pull/130989), [@liggitt](https://github.com/liggitt)) [SIG API Machinery, Apps, Architecture, Auth, CLI, Cloud Provider, Cluster Lifecycle, Etcd,...

## Changelog since v1.8.14

### Action Required

## Changelog since v1.9.8

### Action Required

    * action required: Cloud providers other than GCE might want to update their deployments or sample yaml files to reuse the role created via add-on.

### Other notable changes

* Kubernetes json deserializer is now case-sensitive to restore compatibility with pre-1.8 servers. ([#65157](https://github.com/kubernetes/kubernetes/pull/65157), [@caesarxuchao](https://github.com/caesarxuchao))

* Fixed API server panic during concurrent GET or LIST requests with non-empty `resourceVersion`. ([#65092](https://github.com/kubernetes/kubernetes/pull/65092), [@sttts](https://github.com/sttts))
* Kubernetes json deserializer is now case-sensitive to restore compatibility with pre-1.8 servers. ([#65034](https://github.com/kubernetes/kubernetes/pull/65034), [@caesarxuchao](https://github.com/caesarxuchao))

* Update gogo/protobuf to serialize backward, as to get better performance on deep objects. ([#77355](https://github.com/kubernetes/kubernetes/pull/77355), [@apelisse](https://github.com/apelisse))