- HPA controller exposes the following metrics from the kube-controller-manager. 
  - `metric_computation_duration_seconds`: The time(seconds) that the HPA controller takes to calculate one metric.

- `kube-proxy` in iptables mode will now have separate `sync_full_proxy_rules_duration_seconds`\nand
  `sync_partial_proxy_rules_duration_seconds` (in addition to the existing\n`sync_proxy_rules_duration_seconds`),
  giving better information about the duration of each \nsync type, rather than

- Graduated the following kubelet resource metrics to **general availability**:
  - `container_cpu_usage_seconds_total`
  - `container_memory_working_set_bytes`
  - `container_start_time_seconds`
  - `node_cpu_usage_seconds_total`
  - `node_memory_working_set_bytes`
  - `pod_cpu_usage_seconds_total`
  - `pod_memory_working_set_bytes`
  - `resource_scrape_error`
  

  optional ProbeHandler handler = 1;

  // Number of seconds after the container has started before liveness probes are initiated.
  // More info: https://kubernetes.io/docs/concepts/workloads/pods/pod-lifecycle#container-probes
  // +optional
  optional int32 initialDelaySeconds = 2;

  // Number of seconds after which the probe times out.
  // Defaults to 1 second. Minimum value is 1.

- Deprecated the `apiserver_request_slo_duration_seconds` metric for v1.27 in favor of `apiserver_request_sli_duration_seconds` for naming consistency purposes with other SLI-specific metrics and to avoid any confusion between SLOs and SLIs. ([#112679](https://github.com/kubernetes/kubernetes/pull/112679), [@dgrisonnet](https://github.com/dgrisonnet))...

<code>f</code> is a function returning two values,
</p>

<pre>
x, y = f()
</pre>

<p>
assigns the first value to <code>x</code> and the second to <code>y</code>.
In the second form, the number of operands on the left must equal the number
of expressions on the right, each of which must be single-valued, and the
<i>n</i>th expression on the right is assigned to the <i>n</i>th

- Client-go metrics: change bucket distribution for `rest_client_request_duration_seconds` and `rest_client_rate_limiter_duration_seconds` from [0.001, 0.002, 0.004, 0.008, 0.016, 0.032, 0.064, 0.128, 0.256, 0.512] to [0.005, 0.025, 0.1, 0.25, 0.5, 1.0, 2.0, 4.0, 8.0, 15.0, 30.0, 60.0}] ([#106911](https://github.com/kubernetes/kubernetes/pull/106911), [@aoje...

- Fix incorrectly report scope for request_duration_seconds and request_slo_duration_seconds metrics for POST custom resources API calls. ([#110009](https://github.com/kubernetes/kubernetes/pull/110009), [@azylinski](https://github.com/azylinski)) [SIG Instrumentation]

* API server authentication now caches successful bearer token authentication results for a few seconds. ([#50258](https://github.com/kubernetes/kubernetes/pull/50258), [@liggitt](https://github.com/liggitt))

    String INDEX_REINDEX_BODY = "index.reindex.body";

    /** The key of the configuration. e.g. adaptive */
    String INDEX_REINDEX_requests_per_second = "index.reindex.requests_per_second";

    /** The key of the configuration. e.g. false */
    String INDEX_REINDEX_REFRESH = "index.reindex.refresh";

    /** The key of the configuration. e.g. 1m */