CODEWITHSUNDEEP
rabbitmqamqp
Aurelien
Aurelien

Reputation: 1092

Send a message to every AMQP client, except me

I use RabbitMQ as following :

Now, when client "A" publish a message to the exchange, everyone receive it.

Is there anyway to avoid client "A" to receive its own messages ? (and the same for every client : a client should not receive its own messages)

For the moment I have added a "sender" header with a sender UniqueID and I filter these messages in the client source code, but I think that a better solution should exist.

(in real world situation, I can have many clients, not all clients knows the existence of all other clients)

Thanks.

EDIT :

Maybe direct exchange is not the good solution. Is there any way to fit my needs only with exchange/queue/routing configuration or should I use code in client applications to filter these messages ?

Of course, if I have 1000 clients connected, I can't really use one routing key for each client and send message to 999 routing keys jsut to exclude one.

Upvotes: 1

Views: 2494

Answers (2)

Derick Bailey
Derick Bailey

Reputation: 72888

The short answer is that this can't be done in RabbitMQ, directly.

There are no negations in routing key matches, so you can't say "all, but not this one" with routing keys or bindings.

For the moment I have added a "sender" header with a sender UniqueID and I filter these messages in the client source code, but I think that a better solution should exist.

this is pretty much what you need to do

Upvotes: 2

cantSleepNow
cantSleepNow

Reputation: 10202

From your comment

Every client publish messages the same way : to "FooExchange" exchange, with routing key "FooKey". Every client bind it's queue to "FooKey" on "FooExchange

You are not doing the publishing in the correct way. You must define to which exchange and which routing key.So each subscriber with different routing key, since this is what you want. Check the first tutorial on rabbitmq website. Also bare in mind that when using direct exchange, the name of the queue on the subscribing side is the same as the routing key on the publishing side.

Here is how direct exchange works enter image description here

taken from here.

EDIT to answer the edit in the question
I didn't really understand this part

I can't really use one routing key for each client and send message to 999 routing keys jsut to exclude one.

You would need to specify more precisely what you need.
Anyhow, I suggest that you check out all the types of exchanges:direct, fanout, topic and headers. More info is already in the link I have provided, under the picture.

EDIT2: I think I finally understood what is the use case. If there is no other criteria which you could use to mark the messages or clients, then you'd have to use fanout exchange, and simply don't react on the message if it's "self-sent". Potentially you could use the headers exchange and use some kind of mappings, but it seems that it would end up on the same. AFAIK, there is not pattern for topic exchange that would include NOT something.

Upvotes: 1

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