For the 1.8 release, SIG API Machinery focused on stability and on ecosystem enablement. Features include the ability to break large LIST calls into smaller chunks, improved support for API server customization with either custom API servers or Custom Resource Definitions, and client side event spam filtering.

[Sig API Machinery]: https://github.com/kubernetes/community/tree/master/sig-api-machinery

### SIG Apps

- Introduce `v1beta3` API for scheduler. This version 
  - increases the weight of user specifiable priorities.
  The weights of following priority plugins are increased
    - `TaintTolerations` to 3 - as leveraging node tainting to group nodes in the cluster is becoming a widely-adopted practice
    - `NodeAffinity` to 2

- DRA: scheduling pods is up to 16x faster, depending on the scenario. Scheduling throughput depends a lot on cluster utilization. It is higher for lightly loaded clusters with free resources and gets lower when the cluster utilization increases. ([#127277](https://github.com/kubernetes/kubernetes/pull/127277), [@pohly](https://github.com/pohly)) [SIG API Machinery, Apps, Architecture, Auth,...

  * Note that because any taints you might have created with Kubernetes 1.5 can only affect the scheduling of new pods (the `NoExecute` taint effect is introduced in 1.6), neither the master upgrade nor your running `kubectl taint` to re-create the taints will affect pods that are already running.

### Other notable changes

* CustomResourceDefinitions: OpenAPI v3 validation schemas containing `$ref`references are no longer permitted (valid references could not be constructed previously because property ids were not permitted either). Before upgrading, ensure CRD definitions do not include those `$ref` fields. ([#58438](https://github.com/kubernetes/kubernetes/pull/58438), [@carlory](https://github.com/carlory))

    * 2. IPv4: api-server will assign an IP from a `service-cluster-ip-range` that is `ipv4` (either the primary or the secondary, according to how they were configured).
    * 2. IPv6: api-server will assign an IP from a `service-cluster-ip-range` that is `ipv6` (either the primary or the secondary, according to how they were configured).
    * Notes (v1.16):

use-cases, including network latency sensitive applications, as well as applications that benefit from CPU cache residency.  Next, [Huge Pages](https://kubernetes.io/docs/tasks/manage-hugepages/scheduling-hugepages/), which allows pods to consume either 2Mi or 1Gi Huge Pages.  This benefits applications that consume large amounts of memory.  Use of Huge Pages is a common tuning recommendation for databases and JVMs.  Finally, the [Device Plugin](https://kubernetes.io/docs/concepts/cluster-admini...

- JWT authenticators specified via the `AuthenticationConfiguration.jwt` array can now optionally specify either the `controlplane` or `cluster` egress selector by setting the `i...

    - `apiserver_flowcontrol_demand_seats_high_watermark`: High watermark, over last adjustment period, of demand_seats
    - `apiserver_flowcontrol_demand_seats_average`: Time-weighted average, over last adjustment period, of demand_seats
    - `apiserver_flowcontrol_demand_seats_stdev`: Time-weighted standard deviation, over last adjustment period, of demand_seats
    - `apiserver_flowcontrol_demand_seats_smoothed`: Smoothed seat demands

    ```
    kubectl create clusterrolebinding kube-system-default --serviceaccount=kube-system:default --clusterrole=cluster-admin
    ```

## **Known Issues**