[openamq-dev] Message Queue Storing Technology

[ve3wwg at cogeco.ca]

> On 9/13/07, Warren W. Gay VE3WWG <ve3wwg at cogeco.ca> wrote:
> > What technology/approach is used to store messages that must
> > be delivered to a client, even when it is disconnected (OpenAMQ
> > broker)?  There is a hint that you might be using the Berkeley DB
> > for that-- is this correct?
>
> This is 'persistent messaging'.  AMQP supports it.  OpenAMQ does not.
> In an earlier version we had implemented it, and indeed we used
> Berkeley DB for that.  But that's not linked to in our product today.

Ah, I see.

> There were several reasons to remove the persistent messaging finally.
>  Berkeley DB is particularly horrid.  But more importantly, AMQP does
> not have any way (yet) to do persistent messaging together with
> clustering, and clustering was more important to us.

Ok, I can see where that could get a little "thorny".

> So OpenAMQ implements transient messaging, and aims to be a very
> reliable broker which does clustering and federation.  In OpenAMQ
> projects that need persistence, we recommend you do this at the
> application side (in the framework between WireAPI and the
> application), by using a simple send/ack model where messages are
> resent after a few seconds if not acknowledged.
>
> -
> Pieter Hintjens
> iMatix

Thanks for the very clear and informative answer. It tells
me just what I needed to know.

Warren.