* Fix incorrect retry logic in scheduler ([#50106](https://github.com/kubernetes/kubernetes/pull/50106), [@julia-stripe](https://github.com/julia-stripe))
* Enforce explicit references to API group client interfaces in clientsets to avoid ambiguity. ([#49370](https://github.com/kubernetes/kubernetes/pull/49370), [@sttts](https://github.com/sttts))

- `diskformat` stroage class parameter for in-tree vSphere volume plugin is deprecated as of v1.21 release. Please consider updating storageclass and remove `diskformat` parameter. vSphere CSI Driver does not support diskformat storageclass parameter.
  

* Validate that cronjob names are 52 characters or less ([#52733](https://github.com/kubernetes/kubernetes/pull/52733), [@julia-stripe](https://github.com/julia-stripe))
* add readme file of ipvs ([#51937](https://github.com/kubernetes/kubernetes/pull/51937), [@Lion-Wei](https://github.com/Lion-Wei))



# v1.9.0-alpha.1

## Changes since v1.1.1

### Major Themes

  * <strong>Significant scale improvements</strong>. Increased cluster scale by 400% to 1000 nodes with 30,000 pods per cluster.
Kubelet supports 100 pods per node with 4x reduced system overhead.
  * <strong>Simplified application deployment and management. </strong>
     * Dynamic Configuration (ConfigMap API in the core API group) enables application

* Fix incorrect retry logic in scheduler ([#50106](https://github.com/kubernetes/kubernetes/pull/50106), [@julia-stripe](https://github.com/julia-stripe))

* Use protobufs by default to communicate with apiserver (still store JSONs in etcd) ([#25738](https://github.com/kubernetes/kubernetes/pull/25738), [@wojtek-t](https://github.com/wojtek-t))

- Implemented API for streaming for the `etcd` store implementation.

## External Dependency Version Information

Continuous integration builds have used the following versions of external dependencies, however, this is not a strong recommendation and users should consult an appropriate installation or upgrade guide before deciding what versions of etcd, docker or rkt to use.

* Docker versions 1.10.3, 1.11.2, 1.12.6 have been validated

Replicaset**: the DELETE request of a replication controller or a replicaset becomes asynchronous by default. The object will continue to exist in the key-value store for some time. The API server will set its metadata.deletionTimestamp, add the "orphan" finalizer to its metadata.finalizers. The object will be deleted from the key-value store after the garbage collector orphans its dependents. Please refer to this [user-guide](http://kubernetes.io/docs/user-guide/garbage-collector/) for more information...

## External Dependency Version Information

Continuous integration builds have used the following versions of external dependencies, however, this is not a strong recommendation and users should consult an appropriate installation or upgrade guide before deciding what versions of etcd, docker or rkt to use.

* Docker versions 1.10.3 - 1.12.3
  * Docker version 1.11.2 known issues