Multi vCenter support is deprecated as of v1.21. If you have a Kubernetes cluster spanning across multiple vCenter servers, please consider moving all k8s nodes to a single vCenter Server. vSphere CSI Driver does not support Kubernetes deployment spanning across multiple vCenter servers.
  

### Scheduling

- Multiple Kubernetes clusters can now share the same resource group
    - When upgrading from previous releases, issues will arise with public IPs if multiple clusters share the same resource group. To solve these problems, make the following changes to the cluster:

*   It is now possible to set multiple manifest URL headers with the kubelet's `--manifest-url-header` flag. Multiple headers for the same key will be added in the order provided. The ManifestURLHeader field in KubeletConfiguration object (kubeletconfig/v1alpha1) is now a map[string][]string, which facilitates writing JSON...

- Changed the error message to `cannot exec into multiple objects at a time` when file passed to `kubectl exec` contains multiple resources ([#114249](https://github.com/kubernetes/kubernetes/pull/114249), [@ardaguclu](https://github.com/ardaguclu))

type parameter.
</p>

<p>
Each such pair of matched types corresponds to a <i>type equation</i> containing
one or multiple type parameters, from one or possibly multiple generic functions.
Inferring the missing type arguments means solving the resulting set of type
equations for the respective type parameters.
</p>

<p>
For example, given
</p>

### SIG Multi-cluster (formerly known as SIG Federation)

[SIG Multi-cluster][] is responsible for infrastructure that supports
the efficient and reliable management of multiple Kubernetes clusters,
and applications that run in and across multiple clusters.

For the 1.8 release, SIG Multicluster focussed on expanding the set of
Kubernetes primitives that our Cluster Federation control plane

- Fixes high CPU usage in kubectl drain ([#95260](https://github.com/kubernetes/kubernetes/pull/95260), [@amandahla](https://github.com/amandahla)) [SIG CLI]
- Kube-apiserver: multiple comma-separated protocols in a single X-Stream-Protocol-Version header are now recognized, in addition to multiple headers, complying with RFC2616 ([#89857](https://github.com/kubernetes/kubernetes/pull/89857), [@tedyu](https://github.com/tedyu)) [SIG API Machinery]

- Kube-apiserver: multiple comma-separated protocols in a single X-Stream-Protocol-Version header are now recognized, in addition to multiple headers, complying with RFC2616 ([#89857](https://github.com/kubernetes/kubernetes/pull/89857), [@tedyu](https://github.com/tedyu)) [SIG API Machinery]

    * This keeps the behavior consistent with Docker integration, and fixes an issue that some container Prometheus metrics don't work when there are summary stats for multiple instances of the same pod.
* Add name validation for dynamic client methods in client-go ([#75072](https://github.com/kubernetes/kubernetes/pull/75072), [@lblackstone](https://github.com/lblackstone))