9 thoughts
last posted Aug. 30, 2014, 8:41 p.m.

7 earlier thoughts


RabbitMQ topic exchanges are a powerful tool: they let you publish messages to an exchange and route it to zero or more queues in parallel. They're rapidly becoming the Rabbit tool we turn to first; we've used them as fanout exchanges by "accident", and been happy for the flexibility later.

This weekend we dropped some data on the ground, though, because they route to zero or more queues. If you publish to a routing key that doesn't have a queue bound, the message is dutifully routed... nowhere.

You can set an Alternate Exchange for any Rabbit exchange for handling just this situation: any message that an exchange can't handle will be routed to its alternate exchange, if set.

I know now that when using an exchange, you should always configure an AE for it. It gives you visibility into whether you have routing bugs, as well as a way to recover from those bugs (by replaying the messages into the correct queue).

1 later thought