- `priority_level_seat_count_watermarks` is removed.
  - `priority_level_request_count_samples` is replaced with `priority_level_request_utilization`, which samples every nanosecond rather than every millisecond; the old metric conveyed utilization despite its name.

- Kube-apiserver now reloads serving certificates from disk every minute to allow rotation without restarting the server process ([#84200](https://github.com/kubernetes/kubernetes/pull/84200), [@jackkleeman](https://github.com/jackkleeman))

- 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...

example, `apps/v1 deployments`) and be called when any other version of that resource is modified (for example `extensions/v1beta1 deployments`). This allows new versions of a resource to be handled by admission webhooks without needing to update every webhook to understand the new version. See the API documentation for the `matchPolicy: Equivalent` option in MutatingWebhookConfiguration and ValidatingWebhookConfiguration types. ([#78135](https://github.com/kubernetes/kubernetes/pull/78135), [@l...

</p>

<p>
Implementation restriction: Although numeric constants have arbitrary
precision in the language, a compiler may implement them using an
internal representation with limited precision.  That said, every
implementation must:
</p>

<ul>
	<li>Represent integer constants with at least 256 bits.</li>

	<li>Represent floating-point constants, including the parts of

### Non-recursive Volume Ownership (FSGroup) graduates to Beta

By default, the `fsgroup` setting, if specified, recursively updates permissions for every file in a volume on every mount. This can make mount, and pod startup, very slow if the volume has many files. 

### GCP

- Fixed liveness probe in fluentd-gcp cluster addon ([#74522](https://github.com/kubernetes/kubernetes/pull/74522), [@Pluies](https://github.com/Pluies))
- Reduced GCE log rotation check from 1 hour to every 5 minutes.  Rotation policy is unchanged (new day starts, log file size > 100MB). ([#72062](https://github.com/kubernetes/kubernetes/pull/72062), [@jpbetz](https://github.com/jpbetz))

### Network

- Added a mechanism that calculates a digest of etcd and the watch cache every 5 minutes and exposes it as the `apiserver_storage_digest` metric. ([#130475](https://github.com/kubernetes/kubernetes/pull/130475), [@serathius](https://github.com/serathius)) [SIG API Machinery, Instrumentation and Testing]

* change azure disk host cache to ReadOnly by default ([#72229](https://github.com/kubernetes/kubernetes/pull/72229), [@andyzhangx](https://github.com/andyzhangx))
* Fixes a bug in HPA controller so HPAs are always updated every resyncPeriod (15 seconds). ([#72373](https://github.com/kubernetes/kubernetes/pull/72373), [@krzysztof-jastrzebski](https://github.com/krzysztof-jastrzebski))

- For raw block CSI volumes on Kubernetes, kubelet was incorrectly calling CSI NodeStageVolume for every single "map" (i.e. raw block "mount") operation for a volume already attached to the node. This PR ensures it is only called once per volume per node. ([#112403](https://github.com/kubernetes/kubernetes/pull/112403), [@akankshakumari393](https://g...