* Azure cloudprovider: Reduce the polling delay for all azure clients to 5 seconds. This should speed up some operations at the cost of some additional quota. ([#43699](https://github.com/kubernetes/kubernetes/pull/43699), [@colemickens](https://github.com/colemickens))
* kubeadm: clean up exited containers and network checkpoints ([#43836](https://github.com/kubernetes/kubernetes/pull/43836), [@yujuhong](https://github.com/yujuhong))

    * [fluentd-gcp addon] Bump fluentd-gcp-scaler to v0.5.1 to pick up security fixes.
    * [fluentd-gcp addon] Bump event-exporter to v0.2.4 to pick up security fixes.
    * [fluentd-gcp addon] Bump prometheus-to-sd to v0.5.0 to pick up security fixes.

    * [fluentd-gcp addon] Bump fluentd-gcp-scaler to v0.5.1 to pick up security fixes.
    * [fluentd-gcp addon] Bump event-exporter to v0.2.4 to pick up security fixes.
    * [fluentd-gcp addon] Bump prometheus-to-sd to v0.5.0 to pick up security fixes.

- [stackdriver addon] Bumped prometheus-to-sd to v0.5.0 to pick up security fixes.
[fluentd-gcp addon] Bumped fluentd-gcp-scaler to v0.5.1 to pick up security fixes.
[fluentd-gcp addon] Bumped event-exporter to v0.2.4 to pick up security fixes.
[fluentd-gcp addon] Bumped prometheus-to-sd to v0.5.0 to pick up security fixes.

* [fluentd-gcp-scaler addon] Bump fluentd-gcp-scaler to 0.4 to pick up security fixes. ([#67691](https://github.com/kubernetes/kubernetes/pull/67691), [@loburm](https://github.com/loburm))
    * [prometheus-to-sd addon] Bump prometheus-to-sd to 0.3.1 to pick up security fixes, bug fixes and new features.
    * [event-exporter addon] Bump event-exporter to 0.2.3 to pick up security fixes.

* [fluentd-gcp-scaler addon] Bump fluentd-gcp-scaler to 0.4 to pick up security fixes. ([#67691](https://github.com/kubernetes/kubernetes/pull/67691), [@loburm](https://github.com/loburm))
    * [prometheus-to-sd addon] Bump prometheus-to-sd to 0.3.1 to pick up security fixes, bug fixes and new features.
    * [event-exporter addon] Bump event-exporter to 0.2.3 to pick up security fixes.

* Retry 'connection refused' errors when setting up clusters on GCE. ([#57394](https://github.com/kubernetes/kubernetes/pull/57394), [@mborsz](https://github.com/mborsz))
* Retry 'connection refused' errors when setting up clusters on GCE. ([#57394](https://github.com/kubernetes/kubernetes/pull/57394), [@mborsz](https://github.com/mborsz))

## Changelog since v1.8.0-beta.1

### Action Required

* New GCE or GKE clusters created with `cluster/kube-up.sh` will not enable the legacy ABAC authorizer by default. If you would like to enable the legacy ABAC authorizer, export ENABLE_LEGACY_ABAC=true before running `cluster/kube-up.sh`. ([#51367](https://github.com/kubernetes/kubernetes/pull/51367), [@cjcullen](https://github.com/cjcullen))

### Other notable changes

  - [Changelog since v1.17.0](#changelog-since-v1170)
  - [What’s New (Major Themes)](#whats-new-major-themes)
    - [Kubernetes Topology Manager Moves to Beta - Align Up!](#kubernetes-topology-manager-moves-to-beta---align-up)
    - [Serverside Apply - Beta 2](#serverside-apply---beta-2)

- Added a one-time random duration of up to 50% of kubelet's `nodeStatusReportFrequency` to help spread the node status update load evenly over time. ([#128640](https://github.com/kubernetes/kubernetes/pull/128640), [@mengqiy](https://github.com/mengqiy))