[rabbitmq-discuss] Consumer without a valid connection

Rosa, Andrea andrea.rosa at hp.com
Mon Aug 22 14:35:06 BST 2011

> Sent: 19 August 2011 12:14
> To: Rosa, Andrea
> Cc: rabbitmq-discuss at lists.rabbitmq.com
> Subject: Re: [rabbitmq-discuss] Consumer without a valid connection
> Hi Andrea,

Hi Emile

> On 19/08/11 11:27, Rosa, Andrea wrote:
> > For some reason, that we can't understand, we have got a queue with
> two
> > consumers and one of this consumer is using a channel of a connection
> > that is not present in the list of connections.
> That should not be possible. If you check the connection pid of each
> channel with "rabbitmqctl list_channels connection" each of them should
> appear in the output of "rabbitmqctl list_connections pid". Is that not
> the case?
Sorry for my late reply. I verified and you are right it's not correct what I wrote.
The situation is that I have a queue with two consumer on two different connections. 
It seems that one of this consumer is a "zombie", to fix the situation I closed all connection and restarted my application 
After that there is just one consumer listening on the queue.
Is it possible that rabbitmq DB become inconsistency/corrupted (for some reason) and that creates this situation?
In this case to clean up the db I can delete the mnesia folder and restart the server?
Is it possible to have more details in the rabbitmq log files?

Thanks for your support

> The output of "rabbitmqctl report" will also contain this information.
> > When the publisher send a message to that queue the message is
> grabbed
> > from the queue after 15 minutes!
> There are a few ways to diagnose who is responsible for that delay. You
> could make all connections via the AMQP Tracer:
> http://www.rabbitmq.com/javadoc/com/rabbitmq/tools/Tracer.html
> You could observe the AMQP exchanges on the network between the broker
> and peers using a protocol analyser, such as Wireshark.
> Also consider debugging with the Firehose, which lets you observe
> messages entering and leaving the broker. Avoid the network when
> consuming the firehose messages. For details see
> http://www.rabbitmq.com/firehose.html
> > My questions are:
> >
> > -        How is it possible that the consumer is using a channel on a
> > connection that no more  exists?
> >
> > -        Why there is this delay in grabbing messages? My expectation
> is
> > that the consumer listening to the correct connection can fetch the
> > message immediately
> >
> > -        The "wrong" consumer can block the access to the queue?
> Is the network between the broker and peers reliable? Consider turning
> on AMQP heartbeats if the broker and peers do not about connections.
> Emile

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