Does RabbitMq do round-robin from the exchange to the queues

Question

I am currently evaluating message queue systems and RabbitMq seems like a good candidate, so I'm digging a little more into it.

To give a little context I'm looking to have something like one exchange load balancing the message publishing to multiple queues. I don't want to replicate the messages, so a fanout exchange is not an option.

Also the reason I'm thinking of having multiple queues vs one queue handling the round-robin w/ the consumers, is that I don't want our single point of failure to be at the queue level.

Sounds like I could add some logic on the publisher side to simulate that behavior by editing the routing key and having the appropriate bindings in place. But that's kind of a passive approach that wouldn't take the pace of the message consumption on each queue into account, potentially leading to fill up one queue if the consumer applications for that queue are dead.

I was looking for a more pro-active way from the exchange entity side, that would decide where to send the next message based on each queue size or something of that nature.

I read about Alice and the available RESTful APIs but that seems kind of a heavy duty solution to implement fast routing decisions.

Anyone knows if round-robin between the exchange the queues is feasible w/ RabbitMQ then? Thanks.

Answer 1

One built in way you can do a form of sharing a form exchange to queues, but not exactly round robin, is Consistent Hashing. rabbitmq_consistent_hash_exchange

How too https://medium.com/@eranda/rabbitmq-x-consistent-hashing-with-wso2-esb-27479b8d1d21

Paper to explain, it puts queues at a weighted distribution on a circle and then by sending random routing key it will send to the closest queue. http://www8.org/w8-papers/2a-webserver/caching/paper2.html