public void start() {
    synchronized (lock) {
      if (state == State.NEW) {
        processorListener.beforeStart();
        state = State.STARTED;
        jobCoordinator.start();
      } else {
        LOGGER.info("Start is no-op, since the current state is {} and not {}.", state, State.NEW);
      }
    }
  }
Asynchronously starts this {@link StreamProcessor}.
<p>
  <b>Implementation</b>:
  Starts the {@link JobCoordinator}, which will eventually start the {@link SamzaContainer} when a new
  {@link JobModel} is available.
</p>
samza-core/src/main/java/org/apache/samza/processor/StreamProcessor.java