[rabbitmq-discuss] Headers Exchange

Thu Jan 27 18:19:44 GMT 2011

Hi David,

I know how to construct topic bind strings. :) There's no docs I can
find on Header bind. Help there would be appreciated.

-J

On Thu, Jan 27, 2011 at 11:16 AM, David Wragg <david at rabbitmq.com> wrote:
> "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
>