New alpha features include:
* Online volume resizing will increase the filesystem size of a resized volume without requiring a Pod restart.
* AWS EBS and GCE PD volumes support increased limits on the maximum number of attached volumes per node.

* kubeadm - Increase the manifest upgrade timeout to make upgrades more reliable. ([#65029](https://github.com/kubernetes/kubernetes/pull/65029), [@detiber](https://github.com/detiber))
* Webhooks for the mutating admission controller now support "remove" operation. ([#64971](https://github.com/kubernetes/kubernetes/pull/64971), [@sttts](https://github.com/sttts))

* Increase Horizontal Pod Autoscaler default update interval (30s -> 15s). It will improve HPA reaction time for metric changes. ([#68021](https://github.com/kubernetes/kubernetes/pull/68021), [@krzysztof-jastrzebski](https://github.com/krzysztof-jastrzebski))

* [alpha] Volume resizing

  * You can now increase the size of a volume by calling the Kubernetes API.

  * For alpha, this feature increases only the size of the underlying volume. It does not support resizing the file system.

  * For alpha, volume resizing supports only Gluster volumes.

* fix the create azure file pvc failure if there is no storage account in current resource group ([#56557](https://github.com/kubernetes/kubernetes/pull/56557), [@andyzhangx](https://github.com/andyzhangx))
* Increase allowed lag for ssh key sync loop in tunneler to allow for one failure ([#60068](https://github.com/kubernetes/kubernetes/pull/60068), [@wojtek-t](https://github.com/wojtek-t))

 - Fixes a regression in 1.17 that dropped cache-control headers on API requests ([#90468](https://github.com/kubernetes/kubernetes/pull/90468), [@liggitt](https://github.com/liggitt)) [SIG API Machinery and Testing]
 - Kubeadm: increase robustness for "kubeadm join" when adding etcd members on slower setups ([#90645](https://github.com/kubernetes/kubernetes/pull/90645), [@neolit123](https://github.com/neolit123)) [SIG Cluster Lifecycle]

bumped version of golang it is compiled with to go1.18, which introduced significant changes to its garbage collection algorithm. As a result, we observed an increase in memory usage for kube-apiserver in larger an heavily loaded clusters up to ~25% (with the benefit of API call latencies drop by up to 10x on 99th percentiles). If the memory increase is not acceptable for you you can mitigate by setting GOGC env variable (for our tests using GOGC=63 brings memory usage back to original value, although...

- Fixed a regression preventing garbage collection of RBAC role and binding objects ([#90534](https://github.com/kubernetes/kubernetes/pull/90534), [@apelisse](https://github.com/apelisse)) [SIG Auth]
- Kubeadm: increase robustness for "kubeadm join" when adding etcd members on slower setups ([#90645](https://github.com/kubernetes/kubernetes/pull/90645), [@neolit123](https://github.com/neolit123)) [SIG Cluster Lifecycle]

* fix detach azure disk back off issue which has too big lock in failure retry condition ([#76573](https://github.com/kubernetes/kubernetes/pull/76573), [@andyzhangx](https://github.com/andyzhangx))
* Increase Azure default maximumLoadBalancerRuleCount to 250. ([#72621](https://github.com/kubernetes/kubernetes/pull/72621), [@feiskyer](https://github.com/feiskyer))

* GCE: Bump GLBC version to [0.9.6](https://github.com/kubernetes/ingress/releases/tag/0.9.6). ([#50096](https://github.com/kubernetes/kubernetes/pull/50096), [@nicksardo](https://github.com/nicksardo))
* In GCE with COS, increase TasksMax for Docker service to raise cap on number of threads/processes used by containers. ([#51986](https://github.com/kubernetes/kubernetes/pull/51986), [@yujuhong](https://github.com/yujuhong))