### Network

* `kubectl explain` now uses openapi rather than swagger 1.2. ([#53228](https://github.com/kubernetes/kubernetes/pull/53228), [@apelisse](https://github.com/apelisse))

- `StatefulSetAutoDeletePVC` feature gate promoted to beta. ([#116501](https://github.com/kubernetes/kubernetes/pull/116501), [@mattcary](https://github.com/mattcary))
- `StatefulSet` names must be DNS labels, rather than subdomains. Any `StatefulSet`
  which took advantage of subdomain validation (by having dots in the name) can't
  possibly have worked, because we eventually set `pod.spec.hostname` from the `StatefulSetName`,

- When a CNI plugin returns dual-stack pod IPs, kubelet will now try to respect the
  "primary IP family" of the cluster by picking a primary pod IP of the same family
  as the (primary) node IP, rather than assuming that the CNI plugin returned the IPs
  in the order the administrator wanted (since some CNI plugins don't allow

KEPs or supporting documentation, please reference a specific commit and avoid
linking directly to the master branch. This ensures that links reference a
specific point in time, rather than a document that may change over time.

See here for guidance on getting permanent links to files: https://help.github.com/en/articles/getting-permanent-links-to-files

* Fixes an issue with RBAC reconciliation...

  `sync_partial_proxy_rules_duration_seconds` (in addition to the existing\n`sync_proxy_rules_duration_seconds`),
  giving better information about the duration of each \nsync type, rather than
  only giving a weighted average of the two sync types together. ([#117787](https://github.com/kubernetes/kubernetes/pull/117787), [@danwinship](https://github.com/danwinship))

## Changelog since v1.18.8

## Changes by Kind

### Bug or Regression

- "unbound immediate PersistentVolumeClaims" causes UnschedulableAndUnresolvable status rather than an Error in the scheduler. ([#93892](https://github.com/kubernetes/kubernetes/pull/93892), [@ahg-g](https://github.com/ahg-g)) [SIG Apps and Storage]

### Other notable changes

* Connections from Pods to Services with 0 endpoints will now ICMP reject immediately, rather than blackhole and timeout. ([#72534](https://github.com/kubernetes/kubernetes/pull/72534), [@thockin](https://github.com/thockin))
* Services of type=LoadBalancer which have no endpoints will now immediately ICMP reject connections, rather than time out. ([#74394](https://github.com/kubernetes/kubernetes/pull/74394), [@thockin](https://github.com/thockin))

  - `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.