- Added apiserver_envelope_encryption_kms_operations_latency_seconds metric to measure the KMSv2 grpc calls latency. ([#115649](https://github.com/kubernetes/kubernetes/pull/115649), [@aramase](https://github.com/aramase)) [SIG API Machinery, Auth and Testing]

### Bug or Regression

- An inefficient lock in EndpointSlice controller metrics cache has been reworked. Network programming latency may be significantly reduced in certain scenarios, especially in clusters with a large number of Services. ([#107169](https://github.com/kubernetes/kubernetes/pull/107169), [@robscott](https://github.com/robscott)) [SIG Apps and Network]

identified in large-scale clusters when deleting thousands of pods simultaneously across hundreds of nodes. Kubelets in this scenario can encounter temporarily increased latency of `delete pod` API calls -- above the target service level objective of 1 second. If you run clusters with this usage pattern and if pod deletion latency could be an issue for you, you might want to wait until the issue is resolved before you upgrade.

For more information and for updates on resolution of this...

- Fix: Azure file inline volume namespace issue in CSI migration translation ([#101235](https://github.com/kubernetes/kubernetes/pull/101235), [@andyzhangx](https://github.com/andyzhangx))

- Bug: client-go clientset was not defaulting to the user agent, and was using the default golang agent for all the requests. ([#108772](https://github.com/kubernetes/kubernetes/pull/108772), [@aojea](https://github.com/aojea))

### Bug or Regression

- Bug: client-go clientset was not defaulting the user agent, using the default golang agent for all the requests. ([#108791](https://github.com/kubernetes/kubernetes/pull/108791), [@aojea](https://github.com/aojea)) [SIG API Machinery and Instrumentation]

## Changes by Kind

### API Change

- Revert regression that prevented client-go latency metrics to be reported with a template URL to avoid label cardinality. ([#112055](https://github.com/kubernetes/kubernetes/pull/112055), [@aanm](https://github.com/aanm)) [SIG API Machinery]

### Feature

- Kube-apiserver now reports latency metric for JWT authenticator authenticate token decisions in the `apiserver_authentication_jwt_authenticator_latency_seconds` metric, labeled by jwtIssuer hash and result. ([#123225](https://github.com/kubernetes/kubernetes/pull/123225), [@aramase](https://github.com/aramase))

- `kubelet` now emits a metric for end-to-end pod startup latency, including image pull. ([#121041](https://github.com/kubernetes/kubernetes/pull/121041), [@ruiwen-zhao](https://github.com/ruiwen-zhao))
- `kubelet` now exposes latency metrics of different stages of the node startup. ([#118568](https://github.com/kubernetes/kubernetes/pull/118568), [@qiutongs](https://github.com/qiutongs))

- Reverted regression that prevented `client-go` latency metrics to be reported with a template URL to avoid label cardinality. ([#111752](https://github.com/kubernetes/kubernetes/pull/111752), [@aanm](https://github.com/aanm))