def suspend(self):
    with self._instances_change_lock:
      if self._suspended:
        raise request_info.ServerAlreadyStoppedError()
      self._suspended = True
      with self._condition:
        instances_to_stop = zip(self._instances, self._wsgi_servers)
        for wsgi_servr in self._wsgi_servers:
          wsgi_servr.set_error(404)
    for inst, wsgi_servr in instances_to_stop:
      self._async_suspend_instance(inst, wsgi_servr.port)
Suspends serving for this server, quitting all running instances.
dataset/ETHPy150Open AppScale/appscale/AppServer/google/appengine/tools/devappserver2/server.py/ManualScalingServer.suspend