* GCE: Prefer preconfigured node tags for firewalls, if available ([#25148](https://github.com/kubernetes/kubernetes/pull/25148), [@a-robinson](https://github.com/a-robinson))
* Drain pods created from ReplicaSets in 'kubectl drain' ([#23689](https://github.com/kubernetes/kubernetes/pull/23689), [@maclof](https://github.com/maclof))

## Notable Changes to Existing Behavior

### Deployments

- ReplicaSets of paused Deployments are now scaled while the Deployment is paused. This is retroactive to existing Deployments.
- When scaling a Deployment during a rollout, the ReplicaSets of all Deployments are now scaled proportionally based on the number of replicas they each have instead of only scaling the newest ReplicaSet.

Anyway, the cluster should get back to the proper size after 10 min.

### Deployment

* federation: Adding support for DeleteOptions.OrphanDependents for federated replicasets and deployments. Setting it to false while deleting a federated replicaset or deployment also deletes the corresponding resource from all registered clusters. ([#36476](https://github.com/kubernetes/kubernetes/pull/36476), [@nikhiljindal](https...

- Added warnings about workload resources (Pods, ReplicaSets, Deployments, Jobs, CronJobs, or ReplicationControllers) whose names are not valid DNS labels. ([#114412](https://github.com/kubernetes/kubernetes/pull/114412), [@thockin](https://github.com/thockin))

- API

  - The following APIs are no longer served by default:

    - All resources under `apps/v1beta1` and `apps/v1beta2` - use `apps/v1` instead
    - `daemonsets`, `deployments`, `replicasets` resources under `extensions/v1beta1` - use `apps/v1` instead
    - `networkpolicies` resources under `extensions/v1beta1` - use `networking.k8s.io/v1` instead

- When scaling down a ReplicaSet, delete doubled up replicas first, where a "doubled up replica" is defined as one that is on the same node as an active replica belonging to a related ReplicaSet.  ReplicaSets are considered "related" if they have a common controller (typically a Deployment). ([#80004](https://github.com/kubernetes/kubernetes/pull/80004), [@Miciah](https://github.com/Miciah))

* Make etcd cache size configurable ([#23914](https://github.com/kubernetes/kubernetes/pull/23914), [@jsravn](https://github.com/jsravn))
* Drain pods created from ReplicaSets in 'kubectl drain' ([#23689](https://github.com/kubernetes/kubernetes/pull/23689), [@maclof](https://github.com/maclof))

### Deprecation

#### kube-apiserver:
- the following deprecated APIs can no longer be served:
  - All resources under `apps/v1beta1` and `apps/v1beta2` - use `apps/v1` instead
  - `daemonsets`, `deployments`, `replicasets` resources under `extensions/v1beta1` - use `apps/v1` instead
  - `networkpolicies` resources under `extensions/v1beta1` - use `networking.k8s.io/v1` instead

- When downscaling ReplicaSets, ready and creation timestamps are compared in a logarithmic scale. ([#99212](https://github.com/kubernetes/kubernetes/pull/99212), [@damemi](https://github.com/damemi)) [SIG Apps and Testing]