- Added apiserver_envelope_encryption_invalid_key_id_from_status_total to measure number of times an invalid keyID is returned by the Status RPC call. ([#115846](https://github.com/kubernetes/kubernetes/pull/115846), [@ritazh](https://github.com/ritazh)) [SIG API Machinery and Auth]

*   Added pod-level local ephemeral storage metric to the Summary API. Pod-level ephemeral storage reports the total filesystem usage for the containers and emptyDir volumes in the measured Pod. ([#55447](https://github.com/kubernetes/kubernetes/pull/55447),[ @jingxu97](https://github.com/jingxu97))

#### **Hardware Accelerators**

  or uncacheable. ([#117295](https://github.com/kubernetes/kubernetes/pull/117295), [@aojea](https://github.com/aojea))

* In GCE, add measures to prevent corruption of known_tokens.csv. ([#49897](https://github.com/kubernetes/kubernetes/pull/49897), [@mikedanese](https://github.com/mikedanese))

- New metrics: `apiserver_kube_aggregator_x509_missing_san_total` and `apiserver_webhooks_x509_missing_san_total`. This metric measures a number of connections to webhooks/aggregated API servers that use certificates without Subject Alternative Names. It being non-zero is a warning sign that these connections will stop functioning in the future since Golang is going to deprecate...

  - `read_vs_write_request_count_samples` is replaced with `read_vs_write_current_requests`, which samples every nanosecond rather than every second; the new metric, like the old one, measures utilization when the max-in-flight filter is used and number of requests when the API Priority and Fairness filter is used.

### Feature

- A new metric `apiserver_request_filter_duration_seconds` has been introduced that 
  measures request filter latency in seconds. ([#95207](https://github.com/kubernetes/kubernetes/pull/95207), [@tkashem](https://github.com/tkashem)) [SIG API Machinery and Instrumentation]

- Moving MixedProtocolLBService from alpha to beta ([#109213](https://github.com/kubernetes/kubernetes/pull/109213), [@bridgetkromhout](https://github.com/bridgetkromhout))

- Added kube-apiserver metrics: apiserver_current_inflight_request_measures and, when API Priority and Fairness is enable, windowed_request_stats. ([#91177](https://github.com/kubernetes/kubernetes/pull/91177), [@MikeSpreitzer](https://github.com/MikeSpreitzer)) [SIG API Machinery, Instrumentation and Testing]

   ([#122571](https://github.com/kubernetes/kubernetes/pull/122571), [@p0lyn0mial](https://github.com/p0lyn0mial))
- Added the `apiserver_watch_cache_read_wait` metric to measure the watch cache impact on request latency.
   ([#123190](https://github.com/kubernetes/kubernetes/pull/123190), [@padlar](https://github.com/padlar))