It's a very usefull feature for production processing :)
Oh, I thought everyone had given up on transactions in AMQP, since they have none of the properties that "transactions" are usually considered to have. What are you using them for?
We use it in case when we must have guarantee what if message finally dequeued then it processed, cause in case of server process crashe or restart we cant lost dequeued but not finally processed massages. Only transactions may helps. :(
Perhaps I have misunderstood, but acknowledgements would be adequate for that, wouldn't they?
If the server or the client crashes before 3., the message will get redelivered. Transactions don't make any difference.
It wouldn't be hard to add "transaction" channels to the client API. But I wouldn't want to encourage people to use them, since they don't do what the name suggests.
Did you figure out if you really need them?