title: (Windows Azure) Message Queues - Eventing over multiple machines
body: <p>I am building an application in Windows Azure and require some advice for supplying events to multiple instances, that in turn push them to their respective event subscribers. I was thinking of using Message Queues (Azure Queue Storage). </p>
  
  <p>To give some context, it's a Web application that uses a Comet implementation to push changes to clients. Due to scalability requirements it needs to function in a distributed environment. This implies that clients can be connected to different physical machines.</p>
  
  <p>When a user makes a certain change this needs to be pushed to certain other users. </p>
  
  <p>Using a message queue, all Role instances will have to peek at the message, but there is no way of knowing how many of the roles have looked at the message, so it's not obvious when to delete the queue. I could implement something in the line of counting the amount of roles and incrementing some counter everytime someone peeks. Is there some kind of default implementation for this, and am I going at it the right way?</p>