- kubeadm: fixed an issue where the wrong member list was being reported when removing an etcd member. ([#127650](https://github.com/kubernetes/kubernetes/pull/127650), [@SataQiu](https://github.com/SataQiu))

- Kubeadm: apply further improvements to the tentative support for concurrent etcd member join. Fixes a bug where multiple members can receive the same hostname. Increase the etcd client dial timeout and retry timeout for add/remove/... operations. ([#87505](https://github.com/kubernetes/kubernetes/pull/87505), [@neolit123](https://github.com/neolit123)) [SIG...

- Kubeadm: apply further improvements to the tentative support for concurrent etcd member join. Fixes a bug where multiple members can receive the same hostname. Increase the etcd client dial timeout and retry timeout for add/remove/... operations. ([#87505](https://github.com/kubernetes/kubernetes/pull/87505), [@neolit123](https://github.com/neolit123)) [SIG...

- Kubeadm: added the experimental (alpha) feature gate `EtcdLearnerMode` that allows etcd members to be joined as learner and only then promoted as voting members ([#113318](https://github.com/kubernetes/kubernetes/pull/113318), [@pacoxu](https://github.com/pacoxu))

- Kubeadm: fix wrong member list reported when removing an etcd member ([#127962](https://github.com/kubernetes/kubernetes/pull/127962), [@SataQiu](https://github.com/SataQiu)) [SIG Cluster Lifecycle]

- Moved fluentd-elasticsearch addon images to community controlled location ([#73819](https://github.com/kubernetes/kubernetes/pull/73819), [@coffeepac](https://github.com/coffeepac))
- Removed local etcd members from the etcd cluster when `kubeadm reset` ([#74112](https://github.com/kubernetes/kubernetes/pull/74112), [@pytimer](https://github.com/pytimer))

- Kubeadm: modify the etcd static Pod liveness and readyness probes to use a new etcd 3.5.3+ HTTP(s) health check endpoint "/health?serializable=true" that allows to track the health of individual etcd members and not fail all members if a single member is not healthy in the etcd cluster. ([#110072](https://github.com/kubernetes/kubernetes/pull/110072), [@neolit123](https://github.com/neolit123)) [SIG Cluster Lifecycle]

[Setup topics]: https://kubernetes.io/docs/setup/pick-right-solution/
[SIGs]: https://github.com/kubernetes/community/blob/master/sig-list.md


## Major Themes

Kubernetes is developed by community members whose work is organized into
[Special Interest Groups][]. For the 1.8 release, each SIG provides the
themes that guided their work.

9328), [@divyenpatel](https://github.com/divyenpatel))

* Emit number of bound and unbound persistent volumes as Metrics. This PR adds four kinds of Volume Metrics for kube-controller-manager: bound PVC numbers, unbound PVC numbers, bound PV numbers and unbound PV numbers. The PVC metrics use namespace as dimension and the PV metrics use StorageClassName as its dimension. With these metrics we can better monitor the use of volumes in the cluster. ([#57872](https://github.com/kubernet...

* Upgrade to etcd client 3.3.17 to fix bug where etcd client does not parse IPv6 addresses correctly when members are joining, and to fix bug where failover on multi-member etcd cluster fails certificate check on DNS mismatch ([#83968](https://github.com/kubernetes/kubernetes/pull/83968), [@jpbetz](https://github.com/jpbetz))