RabbitMQ - Wildcard in routing key vs binding key

Question

I'm using rabbitmq to send messages from a single server to multiple clients. I want to send a message to all clients so I have created an exchange which they all bind to. This works great. However, what if I want to send a message to a handful of these clients based on a wildcard in the routing key (not the binding key). For instance, I have say red clients, blue clients and green clients. Sometimes I want all clients to receive the message, sometimes I want just the blue, or just the blue and the red. This is a simplified example. To extend this to my actual system, imagine I have hundreds of "color" distinctions. I can't figure out how to do this as wildcards seem to only exist in binding keys not routing keys.

Any advice will be greatly appreciated.

Answer 1

I think you are trying to do too much with one queue. Considering that you know ahead of time whether the message will go to all clients or just one then you should set up two exchanges. One as a topic, or direct, where the clients will only get the messages specifically intended for them the other as a fanout exchange that will distribute to a different set of queues that will be read by all clients. Header exchanges may allow you the flexibility you want as well and the other possibility is writing a custom exchange to do exactly what you need.