- The default value for node-monitor-grace-period has been increased to 50s (earlier 40s) (Ref - https://github.com/kubernetes/kubernetes/issues/121793) ([#126287](https://github.com/kubernetes/kubernetes/pull/126287), [@devppratik](https://github.com/devppratik)) [SIG API Machinery,...

* Increase waiting time (120s) for docker startup in health-monitor.sh ([#54099](https://github.com/kubernetes/kubernetes/pull/54099), [@dchen1107](https://github.com/dchen1107))

- Client-go: Optimized leaders renewing leases by updating leader lock optimistically without getting the record from the API server first. Also, a new metric `leader_election_slowpath_total` was added to allow users to monitor how many leader elections are updated non-optimistically.
   ([#122069](https://github.com/kubernetes/kubernetes/pull/122069), [@linxiulei](https://github.com/linxiulei))

  - By default, injected tokens are given an extended lifetime so they remain valid even after a new refreshed token is provided. The metric `serviceaccount_stale_tokens_total` can be used to monitor for workloads that are depending on the extended lifetime and are continuing to use tokens even after a refreshed token is provided to the container. If that metric indicates no existing workloads are depending on extended lifetimes, injected token...

* kubeadm: use kubeconfig flag instead of kubeconfig-dir on init phase bootstrap-token ([#71803](https://github.com/kubernetes/kubernetes/pull/71803), [@yagonobre](https://github.com/yagonobre))
* On GCI, NPD starts to monitor kubelet, docker, containerd crashlooping, read-only filesystem and corrupt docker overlay2 issues. ([#71522](https://github.com/kubernetes/kubernetes/pull/71522), [@wangzhen127](https://github.com/wangzhen127))

- If BoundServiceAccountTokenVolume is enabled, cluster admins can use metric `serviceaccount_stale_tokens_total` to monitor workloads that are depending on the extended tokens. If there are no such workloads, turn off extended tokens by starting `kube-apiserver` with flag `--service-account-extend-token-expiration=false` ([#96273](https://github.com/kubernetes/kubernetes/pull/96273),...

- Add three metrics to the job controller to monitor if a job works in healthy condition.
  `IndexedJob` has been promoted to Beta. ([#101292](https://github.com/kubernetes/kubernetes/pull/101292), [@AliceZhang2016](https://github.com/AliceZhang2016))

  - go_sched_latencies_seconds ([#111910](https://github.com/kubernetes/kubernetes/pull/111910), [@tosi3k](https://github.com/tosi3k))
- Added new metric `job_controller_terminated_pods_tracking_finalizer` which can be used to monitor whether the job controller is removing Pod finalizers from terminated Pods after accounting them in Job status. ([#113176](https://github.com/kubernetes/kubernetes/pull/113176), [@alculquicondor](https://github.com/alculquicondor))

     * This method manages the creation and execution of crawler threads,
     * monitors their progress, and handles cleanup operations.
     *
     * <p>The method:</p>
     * <ul>
     *   <li>Creates crawler threads for each data configuration</li>
     *   <li>Manages concurrent execution based on thread count limits</li>
     *   <li>Monitors thread completion and handles cleanup</li>

- Added a new metric `webhook_fail_open_count` to monitor webhooks that fail to open. ([#107171](https://github.com/kubernetes/kubernetes/pull/107171), [@ltagliamonte-dd](https://github.com/ltagliamonte-dd))