[rabbitmq-discuss] Headers Exchange

Thu Jan 27 18:16:09 GMT 2011

"Jason J. W. Williams" <jasonjwwilliams at gmail.com> writes:
> Thank you for the explanation. Are there any docs on how to construct
> the bind string?

For topic exchanges, this is covered at
<http://www.rabbitmq.com/tutorial-five-python.html>.

> Also, is the performance better than topic?

Currently RabbitMQ implements both topic and header exchanges by doing a
linear scan through the bindings.

One day soon, RabbitMQ will optimise the matching involved in topic
exchanges.  But this is designed to improve their performance when used
for typical hierarchical routing situations, and I suspect it will not
give a consistent improvement in cases such as the example I suggested
when comparing topic exchanges to headers exchanges.

There are algorithms to efficiently implement schemes such as the AMQP
headers exchange.  But I don't think we've heard a lot of requests for
us to implement such a thing (perhaps because anyone who did care about
the performance of the headers exchange might also find the constraints
on its functionality to be a problem).

David

-- 
David Wragg
Staff Engineer, RabbitMQ
SpringSource, a division of VMware