### Instrumentation

In v1.9 we focused on improving stability of the components owned by the SIG, including Heapster, Custom Metrics API adapters for Prometheus, and Stackdriver.

### Network

### Structured Logging in Kubelet

  
  Users who maintain controllers which relied on the fact that pods with RestartPolicy=Always
  never enter the Succeeded phase may need to adapt their controllers. This is because as a consequence of 
  the change pods which use RestartPolicy=Always may end up in the Succeeded phase in two scenarios: pod 

* The metrics APIs, `custom-metrics.metrics.k8s.io` and `metrics`, were moved from `v1alpha1` to `v1beta1`, and renamed to `custom.metrics.k8s.io` and `metrics.k8s.io`, respectively. If you have deployed a custom metrics adapter, ensure that it supports the new API version. If you have deployed Heapster in aggregated API server mode, upgrade Heapster to support the latest API version.

- Fix a bug that orphan revision cannot be adopted and statefulset cannot be synced ([#86801](https://github.com/kubernetes/kubernetes/pull/86801), [@likakuli](https://github.com/likakuli)) [SIG Apps]

  - Make "kubeadm upgrade apply" add the "node-role.kubernetes.io/control-plane" label on existing nodes that only have the "node-role.kubernetes.io/master" label during upgrade.
  - Please adapt your tooling built on top of kubeadm to use the "node-role.kubernetes.io/control-plane" label.

instructed to preemptively tolerate the new taint. For clusters that are being upgraded to 1.24 with `kubeadm upgrade apply`, the command will add the new taint `node-role.kubernetes.io/control-plane:NoSchedule` to existing control plane nodes. Please adapt your infrastructure to these changes. In 1.25 the old taint `node-role.kubernetes.io/master:NoSchedule` will be removed. ([#107533](https://github.com/kubernetes/kubernetes/pull/107533), [@neolit123](https://github.com/neolit123))

## Changes...

  - 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
    - `InterPodAffinity` to 2
  

- The kube-controller-manager's deprecated `--experimental-cluster-signing-duration` flag is now removed. Adapt your machinery to use the `--cluster-signing-duration` flag that is available since v1.19. ([#108476](https://github.com/kubernetes/kubernetes/pull/108476), [@ialidzhikov](https://github.com/ialidzhikov))

### Kubernetes release cadence change