title: Message Pump (OnMessage) Causing MaxDeliveryCountExceeded?
body: <p>I have implemented the Message Pump pattern in an Azure Worker Role according to the recommendations.  It is currently configured with AutoComplete = True and MaxConcurrentCalls = 1.</p>
  
  <p>In performing load tests I noticed that as long as I have enough VM instances ready and waiting, the messages get processed fine.  As soon as I try to push too many messages through too few VM instances, a large percentage (over 40%) of the messages are quickly sent to the DLQ with reason of MaxDeliveryCountExceeded.</p>
  
  <p>This goes against my expectation - I would expect messages to back up in the queue and the VM instances to chew through them slowly, but still process them eventually.  In fact, that's why I chose a message queue pattern.</p>
  
  <p>I suspect the Message Pump is the cause.  It feels like behind the scenes it is trying to deliver these messages so fast and furious and the VMs just can't keep up, but in the meantime the delivery counter is being incremented so 10 attempts happens within a few seconds and they end up in the DLQ.</p>
  
  <p>Anyone have a similar experience or guidance for making this work?</p>
  
  <p>Thanks in advance. </p>