No <a href="#Run_time_panics">run-time panic</a> occurs in this case.
</p>


<h3 id="Calls">Calls</h3>

<p>
Given an expression <code>f</code> of <a href="#Function_types">function type</a>
<code>F</code>,
</p>

<pre>
f(a1, a2, … an)
</pre>

<p>
calls <code>f</code> with arguments <code>a1, a2, … an</code>.

### Bug or Regression

- Avoid GCE API calls when initializing GCE CloudProvider for Kubelets.

* Audit logs might impact the API server performance and the latency of large request and response calls. The issue is observed under the following conditions: if `AdvancedAuditing` feature gate is enabled, which is the default case, if audit logging uses the log backend in JSON format, or if the audit policy records large API calls for requests or responses.

For more information, see [#51899](https://github.com/kubernetes/kubernetes/issues/51899).

### Feature

- Added 3 new metrics for monitoring async API calls in the scheduler when the `SchedulerAsyncAPICalls` feature gate was enabled:
    - `scheduler_async_api_call_execution_total`: tracks executed API calls by call type and result (success/error)
    - `scheduler_async_api_call_duration_seconds`: histogram of API call execution duration by call type and result

- Validation rules for Custom Resource Definitions can be written in the [CEL expression lang...

  - Speed up binpacking by reducing the number of PreFilter calls (call once per pod instead of #pods*#nodes times)
  - Speed up finding unneeded nodes by 5x+ in very large clusters by reducing the number of PreFilter calls
  - Expose `--max-nodes-total` as a metric
  - Errors in `IncreaseSize` changed from type `apiError` to `cloudProviderError`

- Made legacy watch calls (`ResourceVersion` = 0 or unset) that generate init-events weigh higher in `API Priority and Fairness (APF)` seat usage. Properly accounting for their cost protects the API server from CPU overload. Users might see increased throttling of such calls as a result. ([#134601](https://github.com/kubernetes/kubernetes/pull/134601), [@shyamjvs](https://github.com/shyamjvs))

- Fixed two regressions introduced by the `PodDisruptionConditions` feature (on by default in 1.26):
  - pod eviction API calls returned spurious precondition errors and required a second evict API call to succeed

    - [CSI Service Account Token](#csi-service-account-token)
    - [CSI Health Monitoring](#csi-health-monitoring)
  - [Known Issues](#known-issues)
    - [<code>TopologyAwareHints</code> feature falls back to default behavior](#topologyawarehints-feature-falls-back-to-default-behavior)
  - [Urgent Upgrade Notes](#urgent-upgrade-notes)
    - [(No, really, you MUST read this before you upgrade)](#no-really-you-must-read-this-before-you-upgrade)

## Before Upgrading

Consider the following changes, limitations, and guidelines before you upgrade:

### **API Machinery**

*   The admission API, which is used when the API server calls admission control webhooks, is moved from `admission.v1alpha1` to `admission.v1beta1`. You must **delete any existing webhooks before you upgrade** your cluster, and update them to use the latest API. This change is not backward compatible.