[rabbitmq-discuss] Management plugin calls bindings routing keys

Steve Powell steve at rabbitmq.com
Wed Jan 25 18:05:39 GMT 2012


David,

Yes, the term binding-key is used in the tutorials, though this is not the term
used by the AMQP specification. Both on the bind Method, and the publish Method
the term used is routing-key. This is unfortunate, but, in general, it is
entirely correct.

The semantics of these keys is entirely up to the exchange. It happens to be the
case that topic exchanges use the bind routing-key as a 'pattern' to match
against the explicit routing-keys that publishers put on their messages.

However, there is no reason why one couldn't implement an exchange type
('cipot'?) where the bindings used explicit keys and the publisher published
with a pattern key. In general, the key on the publication and the keys on the
bindings are used collectively by the exchange to determine where to route the
message. They are both types of 'key' used to route the message.

On the other hand, I agree wholeheartedly that the bind verb ought to have
called it a binding key.

Steve Powell  (a lippy bunny)
----------some more definitions from the SPD----------
vermin (v.) Treating the dachshund for roundworm.
chinchilla (n.) Cooling device for the lower jaw.
socialcast (n.) Someone to whom everyone is speaking but nobody likes.

On 25 Jan 2012, at 16:54, David Stuebe wrote:

> 
> Hi Steve
> 
> That does make sense. And the content of each line is exactly what I would expect. Now that I understand the labels it is fine, but I am still troubled by the idea that the binding contains a routing key. For me, in a topic exchange, the routing key in the message header is a separate and distinct concept from the attribute of the binding that expresses the routing rule. To me it is analogous to an XML doc and an xpath query - two different things.
> 
> Sorry if I have made a mountain out of a mole hill - but the dev team on my project have had a tough time with the semantics of rabbitMQ/AMQP and the overloaded terms that we use in the pubsub model of our application. Calling both of those things 'routing key' was making the distinction more difficult.
> 
> David
> 
> 
> On Wed, Jan 25, 2012 at 10:11 AM, Steve Powell <steve at rabbitmq.com> wrote:
> David,
> 
> It may not be obvious, but what's happening here is that the bindings section
> lists the bindings, ONE PER LINE.
> 
> Each binding is shown as the queue it binds, the routing key, and the arguments.
> The columns are correctly labelled.
> 
> Does that help?
> 
> Steve Powell  (a happy bunny)
> ----------some more definitions from the SPD----------
> vermin (v.) Treating the dachshund for roundworm.
> chinchilla (n.) Cooling device for the lower jaw.
> socialcast (n.) Someone to whom everyone is speaking but nobody likes.
> 
> On 24 Jan 2012, at 11:41, Simon MacMullen wrote:
> 
>> On 23/01/12 20:37, David Stuebe wrote:
>>> The web admin plugin is fantastic for development debugging, but some of
>>> the dev team I work with are having a hard time because it seems like
>>> the web UI is using the wrong name for bindings - it is calling them
>>> routing keys.
>> 
>> Hi David.
>> 
>> Bindings have routing keys, but they also have arguments. In many cases the routing key is used and the arguments aren't - but not all, for example headers exchanges.
>> 
>> Does this make it clearer?
>> 
>> Cheers, Simon
>> 
>> -- 
>> Simon MacMullen
>> RabbitMQ, VMware
>> _______________________________________________
>> rabbitmq-discuss mailing list
>> rabbitmq-discuss at lists.rabbitmq.com
>> https://lists.rabbitmq.com/cgi-bin/mailman/listinfo/rabbitmq-discuss
> 
> 

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