[rabbitmq-discuss] ewbie question - need modified fanaout/publish/subscribe behavior

[scott taggart]

I have now implemented a rather simple message caching server (about 50 
lines of python) that will allow interested clients to inquire into the 
state of a named variable at anytime.  Both the clients and the caching 
server use rabbitmq as their "transports".  Very cool.

On Thursday, November 8, 2012 7:57:29 AM UTC-8, scott taggart wrote:
>
> As I research and better understand AMQP better, I learn that messages are 
> never queued in an exchange - they are always routed to existing queues or 
> tossed.  Given my basic requirement that messages be queued for as-yet 
> non-existent queues, this seems not possible directly with amqp/rabbitmq.
>
> On Wednesday, November 7, 2012 8:40:47 PM UTC-8, scott taggart wrote:
>>
>> the rabbitmq tutorial 3 for python talks about the publish/subscribe 
>> (fanout) model. 
>>
>> I have this working for multiple subscribers but I need something 
>> slightly different. 
>>
>> The current model says that any subscriber sees only the messages AFTER 
>> it subscribes (i.e., creates the subscriber Q) and this is the behavior I 
>> see.  I need to be able to see all messages ever sent to the exchange.  To 
>> be very clear, the current behavior is that if a publisher produces 
>> messages 1, 2, 3 and C1 starts consuming after 2 but before 3, the consumer 
>> only sees 3.  Similarly, if C2 starts after message 3, it never sees 1, 2 
>> or 3.  I need C1 & C2 to see 1, 2, & 3 regardless of where they start in 
>> the publishing sequence. 
>>
>> How can I create the Q after a fanout exchange is created so that that Q 
>> sees all messages sent to an exchange to that point, not just post-Q 
>> creation?  If it takes a different exchange or Q model, please let me know. 
>>
>> Your help is greatly appreciated. 
>>
>>
>> ---- please ecuse me if this message shows up twice - I wan't sure if the 
>> email request I sent earlier would end up here -----
>>
>
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