- Authentication token cache size is increased (from 4k to 32k) to support clusters with many nodes or many namespaces with active service accounts. ([#83643](https://github.com/kubernetes/kubernetes/pull/83643), [@lavalamp](https://github.com/lavalamp))

## Changelog since v1.27.14

## Changes by Kind

### API Change

- Improved scheduling performance when many nodes, and prefilter returns 1-2 nodes (e.g. daemonset)
  

* Reduced the CPU and memory requests for the Metrics Server Nanny sidecar container to free up unused resources.  ([#57252](https://github.com/kubernetes/kubernetes/pull/57252), [@kawych](https://github.com/kawych))

### DNS
* Updates the dnsmasq cache/mux layer to be managed by dnsmasq-nanny. ([#41826](https://github.com/kubernetes/kubernetes/pull/41826), [@bowei](https://github.com/bowei))
  dnsmasq-nanny manages dnsmasq based on values from the
  kube-system:kube-dns configmap:
  ```
  "stubDomains": {
  "acme.local": ["1.2.3.4"]
   },
  ```

  Previously, when unschedulable Pods are updated, the scheduler always put Pods back to activeQ/backoffQ. But, actually not all updates to Pods make Pods schedulable, especially considering many scheduling constraints nowadays are immutable.

- kubeadm: remove misleading error message regarding image pulling ([#66658](https://github.com/kubernetes/kubernetes/pull/66658), [@dixudx](https://github.com/dixudx))
- kubeadm: Pull sidecar and dnsmasq-nanny images when using kube-dns ([#66499](https://github.com/kubernetes/kubernetes/pull/66499), [@rosti](https://github.com/rosti))

- Improved scheduling performance when many nodes, and prefilter returns 1-2 nodes (e.g. daemonset)
  

## Changelog since v1.28.10

## Changes by Kind

### API Change

- Improved scheduling performance when many nodes, and prefilter returns 1-2 nodes (e.g. daemonset)
  

* Default behavior in Cinder storageclass is changed. If availability is not specified, the zone is chosen by algorithm. It makes possible to spread stateful pods across many zones. ([#44798](https://github.com/kubernetes/kubernetes/pull/44798), [@zetaab](https://github.com/zetaab))

* Improve efficiency of preemption logic in clusters with many pending pods. ([#72895](https://github.com/kubernetes/kubernetes/pull/72895), [@bsalamat](https://github.com/bsalamat))