* Fix a scalability issue where high rates of event writes degraded etcd performance. ([#64539](https://github.com/kubernetes/kubernetes/pull/64539), [@ccding](https://github.com/ccding))
* fixes a memory leak in the kube-controller-manager observed when large numbers of pods with tolerations are created/deleted ([#65339](https://github.com/kubernetes/kubernetes/pull/65339), [@liggitt](https://github.com/liggitt))

* fixes a memory leak in the kube-controller-manager observed when large numbers of pods with tolerations are created/deleted ([#65339](https://github.com/kubernetes/kubernetes/pull/65339), [@liggitt](https://github.com/liggitt))

## Known Issues

- When the `PodObservedGenerationTracking` feature gate was set, the kubelet populated `status.observedGeneration` to reflect the latest `metadata.generation` it observed for the pod. ([#130352](https://github.com/kubernetes/kubernetes/pull/130352), [@natasha41575](https://github.com/natasha41575)) [SIG API Machinery, Apps, CLI, Node, Release, Scheduling, Storage, Testing and Windows]

- Kubernetes 1.24 bumped version of golang it is compiled with to go1.18, which introduced significant changes to its garbage collection algorithm. As a result, we observed an increase in memory usage for kube-apiserver in larger an heavily loaded clusters up to ~25% (with the benefit of API call latencies drop by up to 10x on 99th percentiles). If the memory increase is not acceptable for you you can mitigate by setting...

The feature gate currently falls back to the default behavior in most cases. Enabling the feature gate will add hints to `EndpointSlices`, but functional differences are only observed in non-dual stack kube-proxy implementation. This is fixed by [#101054](https://github.com/kubernetes/kubernetes/pull/101054).

## Urgent Upgrade Notes 

### (No, really, you MUST read this before you upgrade)

- Fixed a bug that resulted in "grpc: the client connection is closing" errors shortly after the Kubernetes API server automatically reloaded its encryption-at-rest config due to an observed change to the file.  This bug was only encountered when the --encryption-provider-config-automatic-reload flag was set to true. ([#113955](https://github.com/kubernetes/kubernetes/pull/113955), [@enj](https://github.com/enj)) [SIG API Machinery,...

- A new kubelet command line option, `--reserved-cpus`, is introduced to explicitly define the CPU list that will be reserved for system. For example, if `--reserved-cpus=0,1,2,3` is specified, then cpu 0,1,2,3 will be reserved for the system.  On a system with 24 CPUs, the user may specify `isolcpus=4-23` for the kernel option and use CPU 4-23 for the user containers. ([#83592](ht...

- API
  - Ingress resources will no longer be served from `extensions/v1beta1` in v1.19. Migrate use to the `networking.k8s.io/v1beta1` API, available since v1.14. Existing persisted data can be retrieved via the `networking.k8s.io/v1beta1` API.

  - Ingress resources will no longer be served from `extensions/v1beta1` in v1.20. Migrate use to the `networking.k8s.io/v1beta1` API, available since v1.14. Existing persisted data can be retrieved via the `networking.k8s.io/v1beta1` API.