- Disabled the `SchedulerAsyncAPICalls` feature gate to mitigate a bug where its interaction with asynchronous preemption could degrade `kube-scheduler` performance, especially under high `kube-apiserver` load. ([#134400](https://github.com/kubernetes/kubernetes/pull/134400), [@macsko](https://github.com/macsko))

  Previously, when unschedulable Pods are updated, the scheduler always put Pods back to activeQ/backoffQ. But, actually not all updates to Pods make Pods schedulable, especially considering many scheduling constraints nowadays are immutable.

- Kubernetes will try to acquire the iptables lock every 100 msec during 5 seconds instead of every second. This is especially useful for environments using kube-proxy in iptables mode with a high churn rate of services. ([#85771](https://github.com/kubernetes/kubernetes/pull/85771), [@aojea](https://github.com/aojea)) [SIG Network]

  to fetch the OpenAPI may be slower. ([#118808](https://github.com/kubernetes/kubernetes/pull/118808), [@Jefftree](https://github.com/Jefftree))
- Shrank the `OpenAPI v2` spec by more than 50%, especially for less CPU resource consumption. ([#118204](https://github.com/kubernetes/kubernetes/pull/118204), [@sttts](https://github.com/sttts))

- Eliminated work when creating Services or understanding port purposes, especially for external resources deployed via Helm charts. ([#133018](https://github.com/kubernetes/kubernetes/pull/133018), [@rushmash91](https://github.com/rushmash91))

  - This feature prevents the node and scheduler from oversubscribing resources
    that are still being used by a pod in the process of being cleaned up.
  - This feature can result in increase of Pod Deletion latency especially if the
    pod has a large filesystem footprint.

### RBAC
* **[beta]** RBAC API is promoted to v1beta1 (rbac.authorization.k8s.io/v1beta1), and defines default roles for control plane, node, and controller components.

### Bug or Regression

- An inefficient lock in EndpointSlice controller metrics cache has been reworked. Network programming latency may be significantly reduced in certain scenarios, especially in clusters with a large number of Services. ([#107169](https://github.com/kubernetes/kubernetes/pull/107169), [@robscott](https://github.com/robscott)) [SIG Apps and Network]

* Kubeadm is currently omitting etcd certificates in a self-hosted deployment; this will be fixed in a point relelase. ([#61322](https://github.com/kubernetes/kubernetes/issues/61322))

* Some users, especially those with very large clusters, may see higher memory usage by the kube-controller-manager in 1.10. ([#61041](https://github.com/kubernetes/kubernetes/issues/61041))

that they mount the volumes for. This improves the security posture in the mounting process where the volumes are ACL’ed on the pods’ service account without handing out unnecessary permissions to the CSI drivers’ service account. This feature is especially important for secret-handling CSI drivers, such as the secrets-store-csi-driver. Since these tokens can be rotated and short-lived, this feature also provides a knob for CSI drivers to receive `NodePublishVolume` RPC calls periodically with the...

### Bug or Regression

- An inefficient lock in EndpointSlice controller metrics cache has been reworked. Network programming latency may be significantly reduced in certain scenarios, especially in clusters with a large number of Services. ([#107167](https://github.com/kubernetes/kubernetes/pull/107167), [@robscott](https://github.com/robscott)) [SIG Apps and Network]