[ckan-dev] AMQP topic vs direct exchange

Mon Jan 10 16:00:31 UTC 2011

Hi James,

On Mon, Jan 10, 2011 at 4:31 PM, James Gardner <james at 3aims.com> wrote:
> I had a good look at AMQP over Christmas and from what I can tell,
> workers can't consume a message from a topic queue unless they are
> running at the time the message was sent. This would mean messages sent
> to the queue could be lost even if durability settings were enabled.

This is true. I've had some problems in the past where a lot of items
accumulated on the queue so I chose the topic queue partly for that
reason.

The other reason is that it allows us to play with instance
identifiers, i.e. someone could listen on #.ckan.net to get updates
from all country instances (so you would only have to run the archiver
once instead of per-instance). Since we don't do that at the moment,
this could be removed, though. Either way, it should be a config
setting.

What do the others think?

Best,

 Friedrich