kube-controller manager now use SO_REUSEPORT socket option when listening on address defined by --bind-address and --secure-port flags, when running on Unix systems (Windows is NOT supported). This allows to run multiple instances of those processes on a single host with the same configuration, which allows to update/restart them in a graceful way, without causing downtime. ([#88893](https://github.com/kubernetes/kubernetes/pull/88893), [@invidian](https://github.com/invidian)) [SIG API Machinery, Scheduling...

<code>fmt.Printf</code> or <code>math/rand.Int</code>.
Because the assembler's parser treats period and slash as punctuation,
those strings cannot be used directly as identifier names.
Instead, the assembler allows the middle dot character U+00B7
and the division slash U+2215 in identifiers and rewrites them to
plain period and slash.
Within an assembler source file, the symbols above are written as

 *  Fix: OkHttp no longer shares timeouts between pooled connections. This was
    causing some applications to crash when connections were reused.
 *  Fix: `OkApacheClient` now allows an empty `PUT` and `POST`.
 *  Fix: Websockets no longer rebuffer socket streams.
 *  Fix: Websockets are now better at handling close frames.
 *  Fix: Content type matching is now case insensitive.

	// When versionID is empty, we read directly from the `null` versionID for healing.
	if versionID == "" {
		versionID = nullVersionID
	}

	// Perform quick read without lock.
	// This allows to quickly check if all is ok or all are missing.
	_, errs := readAllFileInfo(healCtx, storageDisks, "", bucket, object, versionID, false, false)
	if isAllNotFound(errs) {
		err := errFileNotFound
		if versionID != "" {

- Graduated relaxed DNS search string validation to GA. For the Pod API, `.spec.dnsConfig.searches`
  now allows an underscore (`_`) where a dash (`-`) would be allowed, and it allows search strings be a single dot `.`. ([#132036](https://github.com/kubernetes/kubernetes/pull/132036), [@adrianmoisey](https://github.com/adrianmoisey)) [SIG Network and Testing]

- **Volume Extension**: There are quite a few enhancements in this release that pertain to volumes and volume modifications. Volume resizing support in CSI specs is moving to beta which allows for any CSI spec volume plugin to be resizable.

### Additional Notable Feature Updates

   * an application-specified ordering of lock acquisitions. The application defines the allowed
   * ordering with an {@code Enum} whose values each correspond to a lock type. The order in which
   * the values are declared dictates the allowed order of lock acquisition. In other words, locks
   * corresponding to smaller values of {@link Enum#ordinal()} should only be acquired before locks

	writeResponse(w, err.HTTPStatusCode, encodedErrorResponse, mimeJSON)
}

// writeCustomErrorResponseJSON - similar to writeErrorResponseJSON,
// but accepts the error message directly (this allows messages to be
// dynamically generated.)
func writeCustomErrorResponseJSON(ctx context.Context, w http.ResponseWriter, err APIError,
	errBody string, reqURL *url.URL,
) {
	reqInfo := logger.GetReqInfo(ctx)

  * Allow configuration of a single security group for ELBs ([#45500](https://github.com/kubernetes/kubernetes/pull/45500), [@nbutton23](https://github.com/nbutton23))

  * Remove check that forces loadBalancerSourceRanges to be 0.0.0.0/0. ([#38636](https://github.com/kubernetes/kubernetes/pull/38636), [@dhawal55](https://github.com/dhawal55))

In particular, a compiler must not introduce writes that do not exist in the original program,
it must not allow a single read to observe multiple values,
and it must not allow a single write to write multiple values.
</p>

<p>
All the following examples assume that `*p` and `*q` refer to
memory locations accessible to multiple goroutines.
</p>