[rabbitmq-discuss] RabbitMQ did not send messages to AMQP consumers

Tue Oct 4 10:20:45 BST 2011

Hi Chris,

On 04/10/11 05:02, Chris Dollmont wrote:
> We send a message from a web application to the RabbitMQ queue. As
> far as we can see, the send operation is successful and RabbitMQ has
> the message in the queue.
> 
> We have amqp listeners on another server that act on the messages
> from the queue. Sometimes, seemingly at random, the messages that we
> know were sent don't arrive--the listeners never get them.
> 
> This happens intermittently. The messages go into the queue and
> appear to be dispatched, but don't arrive at the consumers. There's a
> sporadic period in which this happens, then the situation resolves
> itself.

When you say the message appears to be dispatched, how did you determine
this? Does "rabbitmqctl list_queues" report the queue to be non-empty?
You should also confirm that "rabbitmqctl list_bindings" and
"rabbitmqctl list_consumers" return the expected results and don't
change throughout the period of your test.

Can you reproduce the problem when only a single consumer is subscribed
to the queue? Can you confirm that no consumers retrieve messages
synchronously? I would suggest trying to reproduce the problem with a
minimal client implementation.

Are there any entries in the broker logfile at the time when you expect
the message goes missing?

Have you tried to reproduce the problem while registering a return
listener and publishing messages with the mandatory or immediate flags
turned on?

-Emile