> >Ok. this makes more sense as I think there would not be too many >subscribers. >So you would notify publisher that a new queue has been created? Otherwise >how does publisher push the events out?
Generally idea of pub-sub model is that publisher/subscriber need not be aware the existence of others. In the AMQP case, publisher just publishes events to exchanges and not bother about the consumers. A subscriber interested in a particular set of messages, will create a queue bound to exchange with a binding key with pattern that describes interested messages. It is message broker responsibility to match the message in exchange with all binding key of the queue and deliver the message into queue if message's routing key matches with binding key. So CloudStack just publishes messages to an exchange, and creates a queue for each subscriber and sets up call back to get notified If message gets into a queue.
