[openamq-dev] mandatory routing and immediate delivery

[Pieter Hintjens]

On 10/19/07, Malinga <malingajava at yahoo.com> wrote:

>     Can i know the whats mandatory routing and immediate delivery does
> exactly in amq_client_session_basic_publish method. In your
> documentation theres no clear description for this.

Both flags will cause undeliverable messages to be returned in certain
cases.  The returned messages arrive like delivered messages
(asynchronously) on the session->returned_basic_list, just as
delivered messages arrive on the session->delivered_basic_list.

The mandatory flag means, "return the message if it cannot be routed
by the exchange", and the immediate flag means, "return the message if
it cannot be delivered by the queue right away".

In a typical service-oriented model, each service is a queue bound to
an exchange like amq.direct.  The mandatory flag says, "return the
message if no service is active" and the immediate flag says, "return
the message if the service is busy".

We return the whole message, rather than just headers, so that the
application can process it without any other context.

Hope this helps.

-Pieter