[rabbitmq-discuss] multiple threads in one queue

Fri Oct 1 15:40:22 BST 2010

On Fri, Sep 24, 2010 at 12:35, Isaías <mcallus at gmail.com> wrote:
> In this moment, I have an unique channel and consumer in a main thread, it
> consume the queue and save the content in a normal java queue.
>
> The sons threads get the tasks from java queue, i want know how can I send
> one delay ack because my main thread can not follow consuming the rabbit
> queue if i does not send the ack inmediately.
>
> When the task finishs correctly in a son thread, it saves the task in a
> second queue that main thread read and send the ack for this task to
> eliminate the task from rabbit queue.
>
> Is it possible this??

So you pop messages from RabbitMQ queue and push it into a shared
data structure in Java. Java threads than pop messages from that
shared queue, do the work, and push a new message (ack) onto
another shared queue.

Main thread is responsible for receiving tasks from RabbitMQ and
popping acks from second shared queue and acknowledging them.

- yes, that sounds correct. Though, in my opinion you'll have issues
with the second bit - it's hard (impossible?) to wait both on RabbitMQ
events and on events from shared java queue.

Instead, I propose to send acknowledgments directly from your worker
threads. If I remember correctly, acks are thread-safe and can be
called from every thread.

> or is it better that i have one syncronize channel and
> one syncronize consumer and that all threads consume the rabbit queue?

It might be simpler to just have one AMQP connection for every
worker thread. Why not?

Cheers,
   Marek