// whether to replicate as the target could be temporarily down
		opts.TargetArn = tgtArn
		replicate := cfg.Replicate(opts)
		var synchronous bool
		if tgt != nil {
			synchronous = tgt.replicateSync
		}
		dsc.Set(newReplicateTargetDecision(tgtArn, replicate, synchronous))
	}
	return dsc
}

// Standard headers that needs to be extracted from User metadata.
var standardHeaders = []string{

            if (Thread.currentThread() == this.thread) {
                // we are in the transport thread, ie. on idle disconnecting
                // this is synchronous operation
                // This does not handle compound requests
                synchronized (this.inLock) {
                    final Long peekKey = peekKey();
                    if (peekKey == firstKey) {

     * Returns the final value of the associated {@link ClosingFuture}, or throws an exception as
     * {@link Future#get()} would.
     *
     * <p>Because the asynchronous operation has already completed, this method is synchronous and
     * returns immediately.
     *
     * @throws CancellationException if the computation was cancelled
     * @throws ExecutionException if the computation threw an exception
     */
    @ParametricNullness

It has an interesting, uncommon feature: using the same framework, it's possible to create APIs and also CLIs.

As it is based on the previous standard for synchronous Python web frameworks (WSGI), it can't handle Websockets and other things, although it still has high performance too.

/// info

* Change default value of deleting-pods-burst to 1 ([#27422](https://github.com/kubernetes/kubernetes/pull/27422), [@gmarek](https://github.com/gmarek))
* A new volume manager was introduced in kubelet that synchronizes volume mount/unmount (and attach/detach, if attach/detach controller is not enabled). ([#26801](https://github.com/kubernetes/kubernetes/pull/26801), [@saad-ali](https://github.com/saad-ali))

          }
        }
      } finally {
        unlock();
        postWriteCleanup();
      }

      if (createNewEntry) {
        try {
          // Synchronizes on the entry to allow failing fast when a recursive load is
          // detected. This may be circumvented when an entry is copied, but will fail fast most
          // of the time.
          synchronized (e) {

* Add Priority admission controller for monitoring and resolving PriorityClasses. ([#49322](https://github.com/kubernetes/kubernetes/pull/49322), [@bsalamat](https://github.com/bsalamat))
* apiservers: add synchronous shutdown mechanism on SIGTERM+INT ([#50439](https://github.com/kubernetes/kubernetes/pull/50439), [@sttts](https://github.com/sttts))