title: RabbitMQ Memory Usage grows too high
body: <p>I am experiencing a problem with rabbitmq 2.8.5. There are 3 queues that messages are published to and they are consumed relatively quickly by the consumers. So the queues aren't big at all. 
  There are 3 exchanges one for each queue. 
  However the memory on rabbitmq continues to grow. </p>
  
  <p>I tried running two different commands to understand what was happening to the memory however  rabbitmq would hang when i run them. </p>
  
  <pre><code>rabbitmqctl eval '[[{pid, R}, M | process_info(R)] || {M, R} &lt;- 
  lists:sublist(lists:reverse(lists:sort([{process_info(P, memory), P} || 
  P &lt;- erlang:processes()])), 10)].'
  
  'lists:sublist(lists:reverse(lists:sort([{process_info(Pid,memory), Pid, 
  sys:get_status(Pid,infinity)} || Pid &lt;- [element(7, Q) || Q &lt;- 
  rabbit_amqqueue:list()]])), 10).'
  </code></pre>
  
  <p>I then tried to observe the memory usage on the erlang vm that rabbitmq is running on and it 9235 (I think its in bytes). </p>
  
  <p>So if the queues and exchanges aren't large and Erlang Ram is far below that of rabbitmq what could be the cause? </p>
  
  <p>As the Memory usage continues to grow it eventually reaches the max memory water mark and no more publishing can occur.</p>