PersistentVolumeClaim.
  * Run multiple schedulers in parallel, e.g. one or more custom schedulers
alongside the default Kubernetes scheduler, using pod annotations to select
among the schedulers for each pod. Documentation is [here](http://kubernetes.io/docs/admin/multiple-schedulers.md), design doc is [here](docs/proposals/multiple-schedulers.md).
  * More expressive node affinity syntax, and support for “soft” node affinity.

   * addListener/SES.schedule. The later racy write in cancel() is not guaranteed to be observed,
   * however that is fine since the correctness is based on the atomic state in our base class. The
   * initial write to timer is never definitely visible to Fire.run since it is assigned after
   * SES.schedule is called. Therefore Fire.run has to check for null. However, it should be visible

    /**
     * Shutdown the directory lease manager
     */
    public void shutdown() {
        scheduler.shutdown();
        try {
            if (!scheduler.awaitTermination(5, TimeUnit.SECONDS)) {
                scheduler.shutdownNow();
            }
        } catch (InterruptedException e) {
            scheduler.shutdownNow();
            Thread.currentThread().interrupt();
        }

            log.error("Failed to create handle state directory: " + stateDirectory, e);
        }

        // Load persisted handles on startup
        loadPersistedHandles();

        // Schedule periodic persistence and cleanup
        scheduler.scheduleAtFixedRate(this::periodicMaintenance, 30, 30, TimeUnit.SECONDS);
    }

    /**
     * Request a new durable handle
     * @param path the file path
     * @param type the handle type

```
λ mc admin decommission status alias/ http://minio{1...2}/data{1...4}
ERROR: This pool is not scheduled for decommissioning currently.
```

## Canceling a decommission

Stop an on-going decommission in progress, mainly used in situations when the load may be too high and you may want to schedule the decommission at a later point in time.

    }

    @Override
    public ListenableScheduledFuture<?> schedule(Runnable command, long delay, TimeUnit unit) {
      TrustedListenableFutureTask<@Nullable Void> task =
          TrustedListenableFutureTask.create(command, null);
      ScheduledFuture<?> scheduled = delegate.schedule(task, delay, unit);
      return new ListenableScheduledTask<@Nullable Void>(task, scheduled);
    }

    @Override

  }

  @Override
  public ListenableScheduledFuture<?> schedule(Runnable command, long delay, TimeUnit unit) {
    Preconditions.checkNotNull(command, "command must not be null");
    Preconditions.checkNotNull(unit, "unit must not be null!");
    return schedule(callable(command), delay, unit);
  }

  @Override
  public <V> ListenableScheduledFuture<V> schedule(
      Callable<V> callable, long delay, TimeUnit unit) {

  }

  @Override
  public ListenableScheduledFuture<?> schedule(Runnable command, long delay, TimeUnit unit) {
    Preconditions.checkNotNull(command, "command must not be null");
    Preconditions.checkNotNull(unit, "unit must not be null!");
    return schedule(callable(command), delay, unit);
  }

  @Override
  public <V> ListenableScheduledFuture<V> schedule(
      Callable<V> callable, long delay, TimeUnit unit) {

        for (Map<String, Object> elem : crawlingInfoList) {
            deleteMethod("/api/admin/crawlinginfo/log/" + elem.get("id"));
        }

        // Clean up schedulers
        for (String sId : getSchedulerIds(NAME_PREFIX)) {
            deleteMethod("/api/admin/scheduler/setting/" + sId);
        }

        // Clean up web configs
        for (String wId : getWebConfigIds(NAME_PREFIX)) {

   * This counter prevents an ABA issue where a thread may successfully schedule the worker, the
   * worker runs and exhausts the queue, another thread enqueues a task and fails to schedule the
   * worker, and then the first thread's call to delegate.execute() returns. Without this counter,
   * it would observe the QUEUING state and set it to QUEUED, and the worker would never be
   * scheduled again for future submissions.
   */
  @GuardedBy("queue")