- Added new option to the `InterPodAffinity` scheduler plugin to ignore existing
  pods` preferred inter-pod affinities if the incoming pod has no preferred inter-pod
  affinities. This option can be used as an optimization for higher scheduling throughput
  (at the cost of an occasional pod being scheduled non-optimally/violating existing
  pods preferred inter-pod affinities). To enable this scheduler option, set the

- In clusters where the DryRun feature...

* StatefulSets now include an alpha scaling feature accessible by setting the `spec.podManagementPolicy` field to `Parallel`.  The controller will not wait for pods to be ready before adding the other pods, and will replace deleted pods as needed.  Since parallel scaling creates pods out of order, you cannot depend on predictable membership changes within your set. ([#44899](https://github.com/kubernetes/kubernetes/pull/44899), [@smarterclayton](https://github.com/smarterclayton))...

- Static pods were taking extra time to be restarted after being updated.  Static pods that are waiting to restart were not correctly counted in `kubelet_working_pods`. ([#116995](https://github.com/kubernetes/kubernetes/pull/116995), [@smarterclayton](https://github.com/smarterclayton)) [SIG Node]

memory pressure. ([#58574](https://github.com/kubernetes/kubernetes/pull/58574), [@yastij](https://github.com/yastij))

* New alpha feature limits the number of processes running in a pod. Cluster administrators will be able to place limits by using the new kubelet command line parameter --pod-max-pids. Note that since this is a alpha feature they will need to enable the "SupportPodPidsLimit" feature. By default, we do not set any maximum limit, If an administrator wants to enable this, they...

- 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. ([#87461](https://github.com/kubernetes/kubernetes/pull/87461), [@bboreham](https://github.com/bboreham))...

* **[Pod priority and preemption](https://kubernetes.io/docs/concepts/configuration/pod-priority-preemption/) is now enabled by default.** Note that this means that pods from *any* namespace can now request priority classes that compete with and/or cause preemption of critical system pods that are already running. If that is not desired, disable the PodPriority feature by setting `--feature-gat...

*   StatefulSet controller now creates a label for each Pod in a StatefulSet. The label is `statefulset.kubernetes.io/pod-name`, where `pod-name` = the name of the Pod. This allows users to create a Service per Pod to expose a connection to individual Pods. ([#55329](https://github.com/kubernetes/kubernetes/pull/55329),[ @kow3ns](https://github.com/kow3ns))

      - `kubelet_pod_worker_latency_microseconds` -> `kubelet_pod_worker_duration_seconds`
      - `kubelet_pod_start_latency_microseconds` -> `kubelet_pod_start_duration_seconds`
      - `kubelet_cgroup_manager_latency_microseconds` -> `kubelet_cgroup_manager_duration_seconds`
      - `kubelet_pod_worker_start_latency_microseconds` -> `kubelet_pod_worker_start_duration_seconds`

- Critical pods can now be created in namespaces other than kube-system. To limit critical pods to the kube-system namespace, cluster admins should create an admission configuration file limiting critical pods by default, and a matching quota object in the `kube-system` namespace permitting critical pods in that namespace. See https://kubernetes.io/docs/concepts/policy/resource-quotas/#limit-priority-clas...