* Fix a scalability issue where high rates of event writes degraded etcd performance. ([#64539](https://github.com/kubernetes/kubernetes/pull/64539), [@ccding](https://github.com/ccding))
* Properly manage security groups for loadbalancer services on OpenStack. ([#65373](https://github.com/kubernetes/kubernetes/pull/65373), [@multi-io](https://github.com/multi-io))

* 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))
* Properly manage security groups for loadbalancer services on OpenStack. ([#65373](https://github.com/kubernetes/kubernetes/pull/65373), [@multi-io](https://github.com/multi-io))

upgrading, and deleting clusters.

For the 1.8 release, SIG Cluster Lifecycle continued to focus on expanding the
capabilities of kubeadm, which is both a user-facing tool to manage clusters
and a building block for higher-level provisioning systems. Starting
with the 1.8 release, kubeadm supports a new upgrade command and includes alpha
support for self hosting the cluster control plane.

Besides the above new features, support for Azure Virtual Machine Scale Sets (VMSS) and Cluster-Autoscaler is now stable and considered GA:

- Azure virtual machine scale sets (VMSS) allow you to create and manage identical load balanced VMs that automatically increase or decrease based on demand or a set schedule.

### Serverside Apply - Beta 2

Server-side Apply was promoted to Beta in 1.16, but is now introducing a second Beta in 1.18. This new version will track and manage changes to fields of all new Kubernetes objects, allowing you to know what changed your resources and when.

### Extending Ingress with and replacing a deprecated annotation with IngressClass

* add external resource group support for azure disk ([#64427](https://github.com/kubernetes/kubernetes/pull/64427), [@andyzhangx](https://github.com/andyzhangx))
* Properly manage security groups for loadbalancer services on OpenStack. ([#65373](https://github.com/kubernetes/kubernetes/pull/65373), [@multi-io](https://github.com/multi-io))

  - [beta] In order to preserve safety guarantees the cluster no longer force deletes pods on un-responsive nodes and users are now warned if they try to force delete pods via the CLI. ([docs](http://kubernetes.io/docs/tasks/manage-stateful-set/scale-stateful-set/)) ([kubernetes/features#119](https://github.com/kubernetes/enhancements/issues/119))
- **Auth**

### CSIDriver policy for FSGroup graduates to Beta

The FSGroup's CSIDriver Policy is now beta in 1.20. This allows CSIDrivers to explicitly indicate if they want Kubernetes to manage permissions and ownership for their volumes via `fsgroup`. 

### Security Improvements for CSI Drivers (Alpha)

- Allow kubectl to manage resources by filename patterns without the shell expanding it first ([#102265](https://github.com/kubernetes/kubernetes/pull/102265), [@danielrodriguez](https://github.com/danielrodriguez))

### Server-side Apply graduates to GA