* In-place node upgrades to this release from versions 1.7.14, 1.8.9, and 1.9.4 are not supported if using subpath volumes with PVCs.  Such pods should be drained from the node first.

- The e2e suite can be instructed not to wait for pods in kube-system to be ready or for all nodes to be ready by passing `--allowed-not-ready-nodes=-1` when invoking the e2e.test program. This allows callers to run subsets of the e2e suite in scenarios other than perfectly healthy clusters. ([#98781](https://github.com/kubernetes/kubernetes/pull/98781), [@smarterclayton](https://github....

    *   You can manually set `--cloud-provider=auto-detect`, but be aware that this behavior will be removed completely in a future version.
    *   Best practice for version 1.9 and future versions is to explicitly set a cloud-provider. See [the documentation](https://kubernetes.io/docs/getting-started-guides/scratch/#cloud-providers)
*   The kubeadm `--skip-preflight-checks` flag is now deprecated and will be removed in a future release.

- Kubeadm: fix panic in the command "kubeadm certs check-expiration" when "/etc/kubernetes/pki" exists but cannot be read. ([#124124](https://github.com/kubernetes/kubernetes/pull/124124), [@carlory](htt...

## Action Required

- etcd2 as a backend is deprecated and support will be removed in Kubernetes 1.13.

   - In version 1.9, this behavior will be enabled by default, and must be explicitly
     disabled by setting the `--horizontal-pod-autoscaler-use-rest-clients` flag to `false`.

### Cluster Lifecycle

- The `auto-detect` behavior of the kubelet's `--cloud-provider` flag is deprecated.

  - In version 1.8, the default value for the kubelet's `--cloud-provider` flag is `auto-detect`. Be aware that it works only on GCE, AWS and Azure.

- kube-dns is deprecated and will not be supported in a future version ([#86574](https://github.com/kubernetes/kubernetes/pull/86574), [@SataQiu](https://github.com/SataQiu)) [SIG Cluster Lifecycle]

- Kubeadm: fix panic in the command "kubeadm certs check-expiration" when "/etc/kubernetes/pki" exists but cannot be read. ([#124124](https://github.com/kubernetes/kubernetes/pull/124124), [@carlory](htt...

- client-go discovery clients constructed using `NewDiscoveryClientForConfig` or...

In addition, the NodeRestriction admission plugin now prevents kubelets from modifying taints on their Node API objects, making it easier to keep track of which nodes should be in use.

### SIG CLI