- `kubeadm join --experimental-control-plane` now automatically adds a new etcd member for `local etcd` mode, further simplifying required tasks for HA clusters setup.
- Improvements were made to `kubeadm reset` related to cleaning  etcd and notifying the user about the state of iptables.
- kubeadm commands now print warnings if input YAML documents contain unknown or duplicate fields.

- kubeadm reset: unmount directories under `/var/lib/kubelet` for Linux only ([#81494](https://github.com/kubernetes/kubernetes/pull/81494), [@Klaven](https://github.com/Klaven))
- kubeadm: fix the bug that `--cri-socket` flag does not work for `kubeadm reset` ([#79498](https://github.com/kubernetes/kubernetes/pull/79498), [@SataQiu](https://github.com/SataQiu))

- kubeadm: Added better handling of errors during unmount when calling `kubeadm reset`. When failing to unmount directories under `/var/run/kubelet`, kubeadm will now throw an error instead of showing a warning and continuing to clean up said directory. In such situations, it is better for you to inspect the problem and resolve it manually. Then, you can call `kubeadm reset` again to complete the cleanup.

                final String[] finalRoles = updatedRoles.stream().distinct().toArray(n -> new String[n]);
                user.setGroups(finalGroups);
                user.setRoles(finalRoles);

                // Reset permissions to force recalculation
                user.resetPermissions();

                final long elapsedTime = System.currentTimeMillis() - startTime;
                if (logger.isDebugEnabled()) {

      if (pos == limit) {
        // Empty path: keep the base path as-is.
        return
      }
      val c = input[pos]
      if (c == '/' || c == '\\') {
        // Absolute path: reset to the default "/".
        encodedPathSegments.clear()
        encodedPathSegments.add("")
        pos++
      } else {
        // Relative path: clear everything after the last '/'.

* kubeadm: reset: use crictl to reset containers ([#54721](https://github.com/kubernetes/kubernetes/pull/54721), [@runcom](https://github.com/runcom))

- kubeadm: when adding new control plane nodes with `kubeamd join`, ensure that the etcd member addition is performed only if a given member URL does not already exist in the list of members. Similarly, on "kubeadm reset" only remove an etcd member if its ID exists. ([#127491](https://github.com/kubernetes/kubernetes/pull/127491), [@SataQiu](https://github.com/SataQiu)) [SIG Cluster Lifecycle]

    // If this succeeds, too many requests were made.
    executeSynchronously("/")
      .assertFailure(IOException::class.java)
      .assertFailureMatches(
        "stream was reset: CANCEL",
        "unexpected end of stream on " + server.url("/").redact(),
      )
  }

  @RetryingTest(5)
  @Flaky
  fun recoverWhenRetryOnConnectionFailureIsFalse_HTTP2() {

 *  Fix: Ensure canceled and discarded HTTP/2 data is not permanently counted against the limited
    flow control window. We had a few bugs where window size accounting was broken when streams
    were canceled or reset.
 *  Fix: Recover gracefully if the TLS session returns an unexpected version (`NONE`) or cipher
    suite (`SSL_NULL_WITH_NULL_NULL`).

		enc := json.NewEncoder(&buf)
		for {
			select {
			case <-ctx.Done():
				return
			case li := <-logCh:
				if !li.SendLog(node, logKind) {
					continue
				}
				buf.Reset()
				if err := enc.Encode(li); err != nil {
					continue
				}
				select {
				case <-ctx.Done():
					return
				case encodedCh <- append(grid.GetByteBuffer()[:0], buf.Bytes()...):
				}