I create groups of messages (e.g. G1, G2,...).

Within each group, all messages can be processed in parallel, order does not matter.

However, to process G2, all messages from G1 must have finished processing.

Is it possible to realize this in rabbitmq? (finally I will implement it in symfony...) 

My question is related to [Message Queue with 'Message Barrier' Feature?](https://stackoverflow.com/questions/2397890/message-queue-with-message-barrier-feature)