- 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)....

- Etcd: Updated to v3.5.5. ([#112489](https://github.com/kubernetes/kubernetes/pull/112489), [@dims](https://github.com/dims))
- Fixed Admission controllers that caused unnecessary significant load on `apiserver'. ([#112696](https://github.com/kubernetes/kubernetes/pull/112696), [@aimuz](https://github.com/aimuz))

### Extending Ingress with and replacing a deprecated annotation with IngressClass

### Ingress graduates to General Availability

### SIG Scheduling

- The equivalence class cache has been redesigned to be a two level cache, resulting in a significant increase in scheduling throughput and performance. ([#65714](https://github.com/kubernetes/kubernetes/pull/65714), [@resouer](https://github.com/resouer))

### Azure

SIG Azure worked on improvements in the cloud provider, including significant work on the Azure Load Balancer implementation.

### Cluster Lifecycle

## Major Themes

### Node

### SIG Scheduling
[Pod Priority and Preemption](https://kubernetes.io/docs/concepts/configuration/pod-priority-preemption/) has graduated to Beta, so it is enabled by default. Note that this involves [significant and important changes for operators](https://github.com/kubernetes/sig-release/pull/201/files). The team also worked on improved performance and reliability of the scheduler.

### SIG Storage

actually uses, or expects or is expected to use, the product.  A product
is a consumer product regardless of whether the product has substantial
commercial, industrial or non-consumer uses, unless such uses represent
the only significant mode of use of the product.

  "Installation Information" for a User Product means any methods,
procedures, authorization keys, or other information required to install

## Changelog since v1.21.12

## Changes by Kind

### Bug or Regression

- Correct event registration for multiple scheduler plugins; this fixes a potential significant delay in re-queueing unschedulable pods. ([#109466](https://github.com/kubernetes/kubernetes/pull/109466), [@ahg-g](https://github.com/ahg-g)) [SIG Scheduling and Testing]