maxUnavailable: 0
  maxSurge: 100%

## Update strategy for StatefulSets
statefulSetUpdate:
  updateStrategy: RollingUpdate

## Pod priority settings
## ref: https://kubernetes.io/docs/concepts/configuration/pod-priority-preemption/
##
priorityClassName: ""

## Pod runtime class name
## ref https://kubernetes.io/docs/concepts/containers/runtime-class/
##
runtimeClassName: ""

## Set default rootUser, rootPassword

- Kubeadm: during "upgrade" , if the "etcd.yaml" static pod does not need upgrade, still consider rotating the etcd certificates and restarting the etcd static pod if the "kube-apiserver.yaml" manifest is to be upgraded and if certificate renewal is not disabled. ...

- Prevents a pod from starving pid resource
- Ability to isolate pid resources pod-to-pod and node-to-pod
kubernetes/kubernetes: [#73651](https://github.com/kubernetes/kubernetes/pull/73651)
kubernetes/enhancements: [#757](https://github.com/kubernetes/enhancements/issues/757) [[kep](https://github.com/kubernetes/enhancements/blob/master/keps/sig-node/757-pid-limiting/README.md)]

    - [Certificates](#certificates)
    - [ConfigMap](#configmap)
    - [CronJob](#cronjob)
    - [DaemonSet](#daemonset-1)
    - [Deployment](#deployment-2)
    - [Node](#node)
    - [Pod](#pod)
    - [Pod Security Policy](#pod-security-policy)
    - [RBAC](#rbac-2)
    - [ReplicaSet](#replicaset)
    - [Secrets](#secrets)
    - [Service](#service-1)
    - [StatefulSet](#statefulset-1)

  * A pod can specify its own Hostname and Subdomain via annotations (<code>pod.beta.kubernetes.io/hostname, pod.beta.kubernetes.io/subdomain)</code>. If the Subdomain matches the name of a [headless service](http://kubernetes.io/docs/user-guide/services/#headless-services) in the same namespace, a DNS A record...

  When the scheduling queue receives a cluster event, before moving each Pod from unschedulable pod pool to activeQ/backoffQ, it will call QueueingHintFn of plugins that rejected each Pod in the previous scheduling cycle.
  Depending on the value returned from QueueingHintFn, the scheduling queue changes how it queues each Pod:
  - if more than one QueueingHintFn returns QueueImmediately, it queues Pod to activeQ.

    * Specifically the new controller watches the API server for scheduled pods. It processes each pod and ensures that any volumes that implement the volume Attacher interface are attached to the node their pod is scheduled to.

* Added the `kubeadm upgrade diff` command to show how static pod manifests will be changed by an upgrade. This command shows the changes that will be made to the static pod manifests before applying them. This is a narrower case than kubeadm upgrade apply --dry-run, which specifically focuses on the static pod manifests. ([#63930](https://github.com/kubernetes/kubernetes/pull/63930), [@liztio](https://github.com/liztio))

  connection for such a service arrives on a node when there are no "Ready" endpoints
  for the service, but there is at least one Terminating pod for that service on the node,
  then kube-proxy will send the traffic to the Terminating pod rather than dropping it. This
  patches up a race condition between when a pod is killed and when the external load

* Change scheduler to skip pod with updates only on pod annotations ([#54008](https://github.com/kubernetes/kubernetes/pull/54008), [@yguo0905](https://github.com/yguo0905))