title: apscheduler - multiple instances
body: <p>I have apscheduler running in django and it appears to work ... okay.  In my project <strong>init</strong>.py, I initialize the scheduler:</p>
  
  <pre><code>scheduler = Scheduler(daemon=True)
  
  print("\n\n\n\n\n\n\n\nstarting scheduler")
  
  scheduler.configure({'apscheduler.jobstores.file.class': settings.APSCHEDULER['jobstores.file.class']})
  scheduler.start()
  
  atexit.register(lambda: scheduler.shutdown(wait=False))
  </code></pre>
  
  <p>The first problem with this is that the print shows this code is executed twice.  Secondly, in other applications, I'd like to reference the scheduler, but haven't a clue how to do that.  If I get another instance of a scheduler, I believe it is a separate threadpool and not the one created here.</p>
  
  <ol>
  <li>how do I get one and only one instance of apscheduler running?</li>
  <li>how do I reference that instance in other apps?</li>
  </ol>