code: def restart(self):
          
          BackgroundProcess.objects.filter(pk=self.process_id).update(
              last_update=now(),
              message='restarting..')
          timeout = time() + 60  # wait max 60 seconds
          self.kill_processes(signal.SIGTERM)
          while self.PROCESSES and time() < timeout:
              sleep(0.1)
          self.kill_processes(signal.SIGKILL)
          self.manage_processes()
          logger.debug('BD %d: restarted'%self.process_id)
docs: restart all child processes