- The following features are now GA, and the associated feature gates are deprecated and will be removed in v1.15:
  - `CustomPodDNS`
  - `HugePages`
  - `MountPropagation`
  - `PersistentLocalVolumes`
- CoreDNS: The following directives or keywords are deprecated and will be removed in v1.15:

	</li>

	<li>
	Array types are comparable if their array element types are comparable.
	Two array values are equal if their corresponding element values are equal.
	The elements are compared in ascending index order, and comparison stops
	as soon as two element values differ (or all elements have been compared).
	</li>

	<li>
	Type parameters are comparable if they are strictly comparable (see below).
	</li>

* **[beta]** kubeadm is enhanced and improved with a baseline feature set and command line flags that are now marked as beta. Other parts of kubeadm, including subcommands under `kubeadm alpha`, are [still in alpha](https://kubernetes.io/docs/admin/kubeadm/).  Using it is considered safe, although note that upgrades and HA are not yet supported. Please [try it out](https://kubernetes.io/docs/getting-started-guides/kubeadm/) and [give us feedback](https://kubern...

- Node affinity, Node selectors, and tolerations are now mutable for Jobs that are suspended and have never been started ([#105479](https://github.com/kubernetes/kubernetes/pull/105479), [@ahg-g](https://github.com/ahg-g))

With Kubernetes 1.15 as beta, OpenAPI schemas are also published for CRDs, as long as their schemas are structural.

These changes are reflected in the following Kubernetes enhancements:

* Pod priority and preemption is now enabled by default. Even if you don't plan to use this feature, you might need to take some action immediately after upgrading. In multi-tenant clusters where not all users are trusted, you are advised to create appropriate quotas for two default priority classes,...

  Previously, when unschedulable Pods are updated, the scheduler always put Pods back to activeQ/backoffQ. But, actually not all updates to Pods make Pods schedulable, especially considering many scheduling constraints nowadays are immutable.

The main themes of this release are:

- **Custom resources:** CRDs are in widespread use as a way to extend Kubernetes to persist and serve new resource types, and have been available in beta since the 1.7 release. The 1.16 release marks the graduation of CRDs to general availability (GA).

    * To avoid that negative effect only use per pod metrics from pods that are:
    * - ready (so metrics about them should be valid), or
    * - unready but creation and last readiness change timestamps are apart more than 10s (pods that have formerly been ready and so metrics are in at least some cases (pod becoming unready because of overload) very useful).

com/mtaufen))

* [GCP kube-up.sh] Variables that were part of kube-env that were only used for kubelet flags are no longer being set, and are being replaced by the more portable mechanism of the kubelet configuration file. The individual variables in the kube-env metadata entry were never meant to be a stable interface and this release note only applies if you are depending on them. ([#60020](https://github.com/kubernetes/kubernetes/pull/60020), [@roberthbailey](https://github.com/roberthbailey))...