- CSI Migration: Fixes issue where all volumes with the same inline volume inner spec name were staged in the same path. Migrated inline volumes are now staged at a unique path per unique volume. ([#84754](https://github.com/kubernetes/kubernetes/pull/84754), [@davidz627](https://github.com/davidz627))

* GCE: Fixes ILB sync on legacy networks and auto networks with unique subnet names ([#53410](https://github.com/kubernetes/kubernetes/pull/53410), [@nicksardo](https://github.com/nicksardo))

- In the course of admitting a single request, the ValidatingAdmissionPolicy plugin will perform no more than one authorization check per unique authorizer expression. All evaluations of identical authorizer expressions will produce the same decision. ([#116443](https://github.com/kubernetes/kubernetes/pull/116443), [@benluddy](https://github.com/benluddy)) [SIG API Machinery and Testing]...

* kubelet: resolved hang/timeout issues when running large numbers of pods with unique configmap/secret references ([#74755](https://github.com/kubernetes/kubernetes/pull/74755), [@liggitt](https://github.com/liggitt))

- CustomResourceDefinition schemas that use `x-kubernetes-list-type: map` or `x-kubernetes-list-type: set` now enable validation that the list items in the corresponding custom resources are unique. ([#84920](https://github.com/kubernetes/kubernetes/pull/84920), [@sttts](https://github.com/sttts)) [SIG API Machinery]
 
#### Configuration file changes:

#### kube-apiserver:

* Fix metrics API group name in audit configuration ([#53493](https://github.com/kubernetes/kubernetes/pull/53493), [@piosz](https://github.com/piosz))
* GCE: Fixes ILB sync on legacy networks and auto networks with unique subnet names ([#53410](https://github.com/kubernetes/kubernetes/pull/53410), [@nicksardo](https://github.com/nicksardo))

- The calculation of pod UIDs for static pods has changed to ensure each static pod gets a unique value - this will cause all static pod containers to be recreated/restarted if an in-place kubelet upgrade from 1.20 to 1.21 is performed. Note that draining pods before upgrading the kubelet across minor versions is the supported upgrade path. (...

* kubelet: resolved hang/timeout issues when running large numbers of pods with unique configmap/secret references ([#74755](https://github.com/kubernetes/kubernetes/pull/74755), [@liggitt](https://github.com/liggitt))

### Other notable improvements

  * Job was Beta in 1.1 and is GA in 1.2 .
     * <code>apiVersion: batch/v1 </code>is now available.  You now do not need to specify the <code>.spec.selector</code> field — a [unique selector is automatically generated ](http://kubernetes.io/docs/user-guide/jobs/#pod-selector)for you.

- Kubelet external Credential Provider feature is moved to GA. Credential Provider Plugin and Credential Provider Config APIs updated...