title: Does same Storm spout receive acked/failed message in parallel
body: <p>My Storm Spout contains a <code>Map&lt;Object, Foo&gt;</code> of message Id objects with their corresponding Foo objects I'm emitting. Every time the spout processes a message in <code>nextTuple()</code>, the message Id with the Foo object is added to the map. When fail is called in the Spout, I use the message Id object to retrieve the Foo object from the map and replay the message (guaranteed message processing). On ack, I remove the message from the map.</p>
  
  <p>This works for a single instance of the spout. I'm trying to verify if this will work if I parallelize the Spout, i.e. is a message always acked/failed by the spout that emitted it or can another instance of the spout pick up the ack/fail call?</p>