[rabbitmq-discuss] active/active HA and publishers/consumers

Thu Sep 8 15:06:03 BST 2011

On Thu, Sep 08, 2011 at 03:03:13PM +0100, Matthew Sackman wrote:
> On Thu, Sep 08, 2011 at 06:40:19AM -0700, Steve Martin wrote:
> > I, too, would like to echo John's initial query.
> > I have an active/active HA cluster and would like to seek some
> > guidance on how best to configure my system with regards to how to
> > know where to publish to/consume from.
> > If the master fails and a slave is promoted, how do I know what the
> > new master is or can I publish to the slave (my thoughts are no but I
> > have to ask)?
> 
> You can publish from _any_ node in the cluster. It doesn't matter. The
> nodes in the cluster know where the master is and will forward
> publications internally.

Don't forget that you publish to _exchanges_ not queues (though the
nameless exchange exists to provide a mechanism which does allow
addressing of queues). Consequently the queues to which the message is
destined could be on any number of different nodes within the cluster.
In such a scenario, there is no "right" node to publish to.

Matthew