[rabbitmq-discuss] Queue disappears during high volume federation

Tue Aug 14 16:59:59 BST 2012

Matt,

On 14/08/12 01:25, Matt Pietrek wrote:
> I'm hitting an issue where a queue disappears from underneath me in a
> high volume federated scenario.
>
> Background: I'm on RabbitMQ 2.8.5 on top of Ubuntu 10.04.
>
> I have three brokers bi-directionally federated similarly to the "Small
> complete Graph" example in http://www.rabbitmq.com/federation.html. My
> exchange is called "Skytap", and is a topic exchange. One of the routing
> key 'words' directs messages to the appropriate broker.
>
> In my example, I have a single master sending "requests" to two slaves
> which reply back to the master, simulating an RPC scenario. A client app
> on the 'master' broker reads from an exclusive queue called 'master",
> while client apps on the slave brokers read from an exclusive queue
> called "slave'.
>
> In the low volume case, everything works as expected: A steady stream of
> request messages seen on the slaves and a steady stream of reply
> messages seen on the master.
>
> However, if I write "request" messages as fast as possible, in short
> order I see the 'master' queue disappear. (I know this because I have
> mnesia logging turned on.)

Since the 'master' queue is exclusive, and there is nothing unusual in 
the rabbit logs indicating any rabbit-internal problems (you've checked 
the sasl log as well, right?) the only way that queue can vanish is for 
it to be either deleted explicitly by the creating connection or for the 
connection to have been closed.

Can't see how federation would have anything to do with this since it is 
not touching user queues.

Matthias.