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- An end-user may choose to request logs without confirming the identity of the backing kubelet.  This feature can be disabled by setting the `AllowInsecureBackendProxy` feature-gate to false. ([#83419](https://github.com/kubernetes/kubernetes/pull/83419), [@deads2k](https://github.com/deads2k))

  - if more than one QueueingHintFn returns QueueImmediately, it queues Pod to activeQ.
  - If no QueueingHintFn returns QueueImmediately and more than one plugin returns QueueAfterBackoff, it queues Pod to backoffQ if Pod is backing off, or to activeQ if Pod's backoff has already finished.
  - If all QueueingHintFn return QueueSkip, it puts this pod back to the unschedulable pod pool
  

- Removed deprecated command `kubectl stop`.

- Kubectl can now use http caching for the OpenAPI schema. The cache
  directory can be configured by passing the `--cache-dir` command line flag to kubectl.
  If set to an empty string, caching is disabled.

- Kubectl now performs validation against OpenAPI schema instead of Swagger 1.2. If

#### kube-apiserver:
- in an `--encryption-provider-config` config file, an explicit `cacheSize: 0` parameter previously silently defaulted to caching 1000 keys. In Kubernetes 1.18, this now returns a config validation error. To disable caching, you can specify a negative cacheSize value in Kubernetes 1.18+.