[rabbitmq-discuss] Passing null for 'arguments' to queueBind()

Fri Nov 12 17:43:38 GMT 2010

>> It *is* a problem though when the groups are formed dynamically on
>> a per message basis, i.e. when each consumer has a unique secret
>> token, known to the producer, and the producer constructs the
>> recipient group of the message on the fly by including all the
>> intended recipient's tokens in the message headers.
>
> I understand you now, and above is exactly the situation I have.  I
> wonder if a custom exchange type can remove headers from a message
> prior to delivery.

Here is a design:

Allow CC and BCC fields* when publishing.  These are given to exchange 
types** when routing (i.e., they are part of the envelope); and, the 
routing code removes Bcc before actually delivering to queues.

Full semantics left as an exercise*** for the reader.

* They would probably have to be put in message headers, but possibly 
they could be given specific support in our clients.

** We'd update direct and topic to take account of them; fanout and 
headers don't need to, and other types given be given the fields and do 
what they like.

*** For example, "" is a valid routing key, so how do you send to 
multiple recipients just with BCC field?

Michael