[rabbitmq-discuss] Exactly Once Delivery

[Matthew Sackman]

On Fri, Aug 06, 2010 at 10:43:56PM +0100, Tim Fox wrote:
> The way we do it in HornetQ is we have a well defined header key
> "_HQ_DUP_ID". The client can set this with some unique value of it's
> choice before sending (e.g. a GUID). When the server receives the
> message if the _HQ_DUP_ID header is set, it looks up the value in
> it's cache, and if it's seen it before it ignores it. The cache can
> optionally be persisted.

How do you prevent the cache from growing without bound?

Matthew