code: public void start() throws Exception
      {
          Preconditions.checkState(state.compareAndSet(State.LATENT, State.STARTED), "Cannot be started more than once");
  
          client.createContainers(queuePath);
  
          getInitialQueues();
          leaderLatch.start();
  
          service.submit
          (
              new Callable<Void>()
              {
                  @Override
                  public Void call() throws Exception
                  {
                      while ( state.get() == State.STARTED )
                      {
                          try
                          {
                              Thread.sleep(policies.getThresholdCheckMs());
                              checkThreshold();
                          }
                          catch ( InterruptedException e )
                          {
                              // swallow the interrupt as it's only possible from either a background
                              // operation and, thus, doesn't apply to this loop or the instance
                              // is being closed in which case the while test will get it
                          }
                      }
                      return null;
                  }
              }
          );
      }
docs: The sharder must be started
  
  @throws Exception errors