### Bug or Regression

	([docs](http://kubernetes.io/docs/user-guide/federation/federated-ingress.md))
	([kubernetes/features#82](https://github.com/kubernetes/enhancements/issues/82))
  - [beta] `Federated Replica Sets` create and maintain matching
    `Replica Set`s in some or all clusters in a federation, with the
    desired replica count distributed equally or according to
    specified per-cluster weights.

        // No matching host header
        String key = virtualHostHelper.getVirtualHostKey();
        assertEquals("", key);

        // Matching host header
        request.addHeader("Host", "example.com");
        key = virtualHostHelper.getVirtualHostKey();
        assertEquals("", key); // Still empty due to caching

        // Test caching by calling again - should return cached value

#### Cluster Selection
* [alpha] Federation [ClusterSelector annotation](https://kubernetes.io/docs/tasks/administer-federation/cluster/#clusterselector-annotation) to direct objects to federated clusters with matching labels.


### **Instrumentation**
#### Core Metrics API

- **Exception Handling** (`org.codelibs.core.exception`) - Runtime exception wrappers for common checked exceptions with consistent error handling

### Modern Java 21 Support
- **Pattern Matching** - Leverages modern Java pattern matching for efficient type checking and conversion
- **Switch Expressions** - Optimized implementations using switch expressions for better performance

- Namespace API objects now have a `kubernetes.io/metadata.name` label matching their metadata.name field to allow selecting any namespace by its name using a label selector. ([#96968](https://github.com/kubernetes/kubernetes/pull/96968), [@jayunit100](https://github.com/jayunit100)) [SIG API Machinery, Apps, Cloud Provider,...

- Fix output of `kubectl get --watch-only` when watching a single resource ([#79345](https://github.com/kubernetes/kubernetes/pull/79345), [@liggitt](https://github.com/liggitt))

     * @param fields array of fields to search in
     * @param excludes array of words to exclude from results
     * @return list of popular words matching the criteria
     */
    public List<String> getWordList(final SearchRequestType searchRequestType, final String seed, final String[] tags, final String[] roles,
            final String[] fields, final String[] excludes) {

     * @param available whether to filter only available configurations
     * @param idList the list of configuration IDs to retrieve, or null for no ID filtering
     * @return a list of WebConfig objects matching the criteria
     */
    public List<WebConfig> getAllWebConfigList(final boolean withLabelType, final boolean withRoleType, final boolean available,
            final List<String> idList) {

### **Instrumentation**

#### **Audit**

*   Adjust batching audit webhook default parameters: increase queue size, batch size, and initial backoff. Add throttling to the batching audit webhook. Default rate limit is 10 QPS. ([#53417](https://github.com/kubernetes/kubernetes/pull/53417),[ @crassirostris](https://github.com/crassirostris))