* 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))
* Improve efficiency of preemption logic in clusters with many pending pods. ([#72895](https://github.com/kubernetes/kubernetes/pull/72895), [@bsalamat](https://github.com/bsalamat))

callers to pass a `context.Context` as an argument. The context is used for timeout and cancellation signaling and to pass supplementary information to round trippers in the wrapped transport chain. If you don't need any of this functionality, it is sufficient to pass a context created with `context.Background()` to these functions. The `(*"k8s.io/client-go/rest".Request).Context` method is removed now that all methods that execute a request accept a context directly. ([#87597](https://github.com/kub...

- Added new config option `delayCacheUntilActive` to `KubeSchedulerConfiguration` that can provide a tradeoff between memory efficiency and scheduling speed when their leadership is updated in `kube-scheduler` ([#115754](https://github.com/kubernetes/kubernetes/pull/115754), [@linxiulei](https://github.com/linxiulei)) [SIG API Machinery and Scheduling]

   ([#113629](https://github.com/kubernetes/kubernetes/pull/113629), [@andrewsykim](https://github.com/andrewsykim))
- 'The iptables kube-proxy backend now process service/endpoint changes
  more efficiently in very large clusters.' ([#110268](https://github.com/kubernetes/kubernetes/pull/110268), [@danwinship](https://github.com/danwinship))
- '`CSIMigrationvSphere` was upgraded to GA and locked to true. Do not upgrade to K8s

Node.  There is an open PR ([#48189](https://github.com/kubernetes/kubernetes/pull/48189)) to resolve this issue, but as this issue also exists in 1.6, and as we do not wish to risk release stability by merging it directly prior to a release without sufficient testing, we have decided to defer merging the PR until the next point release for each minor version ([#48190](https://github.com/kubernetes/kubernetes/pull/48190)).

* Protobuf serialization does not distinguish between `[]` and `null`....

* Do not detach volume if mount in progress ([#71145](https://github.com/kubernetes/kubernetes/pull/71145), [@gnufied](https://github.com/gnufied))
* Improve efficiency of preemption logic in clusters with many pending pods. ([#72895](https://github.com/kubernetes/kubernetes/pull/72895), [@bsalamat](https://github.com/bsalamat))

user stories, such as the high availability use cases have been given priority for 1.15.

kubeadm, the cluster lifecycle building block, continues to receive features and stability work required for bootstrapping production clusters efficiently. kubeadm has promoted high availability (HA) capability to beta, allowing users to use the familiar `kubeadm init` and `kubeadm join` commands to [configure and deploy an HA control plane](https://kubernetes.io/docs/setup/production-environment...

inherent in its design. This PR exposes a second, independent pruning alpha powered by a new standard named `ApplySets`. An `ApplySet` is a server-side object (by default, a Secret; ConfigMaps are also allowed) that kubectl can use to accurately and efficiently track set membership across `apply` operations. The format used for `ApplySet` is set out in  [KEP 3659](https://github.com/kubernetes/enhancements/issues/3659) as a low-level specification.  Other tools in the ecosystem can also build on this specification...

* Allow for watching objects larger than 1MB given etcd accepts objects of size up to 1.5MB ([#72053](https://github.com/kubernetes/kubernetes/pull/72053), [@wojtek-t](https://github.com/wojtek-t))
* Improve efficiency of preemption logic in clusters with many pending pods. ([#72895](https://github.com/kubernetes/kubernetes/pull/72895), [@bsalamat](https://github.com/bsalamat))



# v1.12.5

[Documentation](https://docs.k8s.io)

### Bug or Regression