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rabbitmqamqp

RabbitMQ headers exchange routing: match all listed headers

I have a lot of consumers with different set of features, so I want route message to process to correct one. I decided use headers exchange and specify necessary features in message headers, but here fall into obstacle.

In rabbitMQ there is binding argument x-match which may take values only any and all (https://lists.rabbitmq.com/pipermail/rabbitmq-discuss/2013-July/028575.html). Each consumer instead while binds has big list of available features (most of them are true/false, but also there are strings), which I specify as binding arguments along with x-match argument. But when I publish message I wanna specify only necessary headers, for instance, feature-1 and feature-7 with specific values. I don't even know about all available consumer features when publish the message. And here is problem: if I miss some of binding argument when x-match==all, message won't be routed, and if I set x-match to any, the only matching header is enough to route message - despite another header's value may not match.

To give you example, let's consider consumer with features: country=US, f1=true, f2=true, f3=false.

  • Scenario 1: So I attach (create binding) its queue to headers exchange with these arguments and x-match set to all. Then I publish message and I need country to be "US" and f2 to be true. I don't know anything about other possible consumer features. Message won't be routed, because not all headers match exactly.
  • Scenario 2: Another use case is if I bind queue with x-match argument set to any. If I specify again country to be "US" and f2 to be true - message will be routed, but also it will be (incorrectly) routed if f2 is set to false and only country matches.

So probably I misunderstand something, but I look for easiest solution for me: how to route message to right consumer based on list of necessary features. I would like to use something like all-specified value for x-match argument which wouldn't demand list all available features but will require all given headers to match exactly.

Solution

  • Indeed, only own exchange may help for my purpose. If I'm succeed in erlang I'll report here.

    Update

    I managed to write own plugin which fits my purposes. Probably it is not perfect but works good for me for now.

    https://github.com/senseysensor/rabbitmq-x-features-exchange