title: celery worker - connection already closed error
body: <p>I am working with Flask and remote celery worker, for celery communication I am using rabbitmq as message broker.
  The remote celery worker randomly throws error as follows:-</p>
  <pre><code>[2020-09-03 13:49:59,390: CRITICAL/MainProcess] Couldn't ack 20, reason:RecoverableConnectionError(None, 'connection already closed', None, '')
  Traceback (most recent call last):
    File &quot;c:\users\g-us01.test\.virtualenvs\celery_doors_integration-o4w-mxzx\lib\site-packages\kombu\message.py&quot;, line 131, in ack_log_error
      self.ack(multiple=multiple)
    File &quot;c:\users\g-us01.test\.virtualenvs\celery_doors_integration-o4w-mxzx\lib\site-packages\kombu\message.py&quot;, line 126, in ack
      self.channel.basic_ack(self.delivery_tag, multiple=multiple)
    File &quot;c:\users\g-us01.test\.virtualenvs\celery_doors_integration-o4w-mxzx\lib\site-packages\amqp\channel.py&quot;, line 1394, in basic_ack
      spec.Basic.Ack, argsig, (delivery_tag, multiple),
    File &quot;c:\users\g-us01.test\.virtualenvs\celery_doors_integration-o4w-mxzx\lib\site-packages\amqp\abstract_channel.py&quot;, line 56, in send_method
      raise RecoverableConnectionError('connection already closed')
  amqp.exceptions.RecoverableConnectionError: connection already closed
  </code></pre>
  <p>I am using celery version 4.
  Any pointers on how to avoid this error would be helpful.</p>