- Kubernetes will try to acquire the iptables lock every 100 msec during 5 seconds instead of every second. This is especially useful for environments using kube-proxy in iptables mode with a high churn rate of services. ([#85771](https://github.com/kubernetes/kubernetes/pull/85771), [@aojea](https://github.com/aojea)) [SIG...

- Renames the timeout field for the DelegatingAuthenticationOptions to TokenRequestTimeout and set the timeout only for the token review client. Previously the timeout was also applied to watches making them reconnecting every 10 seconds. ([#101102](https://github.com/kubernetes/kubernetes/pull/101102), [@p0lyn0mial](https://github.com/p0lyn0mial)) [SIG API Machinery, Auth and Cloud Provider]

- Fixed kubelet startup getting stuck with `NewVolumeManagerReconstruction` feature enabled and a...

* Kubeadm is currently omitting etcd certificates in a self-hosted deployment; this will be fixed in a point relelase. ([#61322](https://github.com/kubernetes/kubernetes/issues/61322))

* Some users, especially those with very large clusters, may see higher memory usage by the kube-controller-manager in 1.10. ([#61041](https://github.com/kubernetes/kubernetes/issues/61041))

previous list call repeatedly until all results are retrieved.  The resulting list is identical to a list call that does not perform chunking thanks to capabilities provided by etcd3.  This allows the server to use less memory and CPU responding with very large lists.  This feature is gated as APIListChunking and is not enabled by default.  The 1.9 release will begin using this by default from all informers. ([#48921](https://github.com/kubernetes/kubernetes/pull/48921), [@smarterclayton](https://g...

- Fix: The volume is not detached after the pod and PVC objects are deleted. ([#116138](https://g...

* Adds the `Categories []string` field to API resources, which represents the list of group aliases (e.g. "all") that every resource belongs to.  ([#43338](https://github.com/kubernetes/kubernetes/pull/43338), [@fabianofranz](https://github.com/fabianofranz))

* Fixes a bug in HPA controller so HPAs are always updated every resyncPeriod (15 seconds). ([#72373](https://github.com/kubernetes/kubernetes/pull/72373), [@krzysztof-jastrzebski](https://github.com/krzysztof-jastrzebski))

  - `priority_level_seat_count_watermarks` is removed.
  - `priority_level_request_count_samples` is replaced with `priority_level_request_utilization`, which samples every nanosecond rather than every millisecond; the old metric conveyed utilization despite its name.

### Non-recursive Volume Ownership (FSGroup) graduates to Beta

By default, the `fsgroup` setting, if specified, recursively updates permissions for every file in a volume on every mount. This can make mount, and pod startup, very slow if the volume has many files.