On 05/21/2010 02:43 PM, Martin Ritchie wrote:
On 1 April 2010 01:26, Aidan Skinner<[email protected]> wrote:
I've recently been wrestling with transaction handling in the java
broker in the context of 0-9-1 compliance. We're currently not
strictly spec compliant with 0-9-1 as we will resend messages that
have been rolled back. 0-9 and 0-8 are... ambiguous... on this matter,
and I've been trying to retain current behaviour for them.
However, it's a) a massive PITA and b) probably Not What You Want. If
you're rolling back a consume it's almost certainly because you can't
cope with the message.
If you think b) I'd like to float the idea of 0.8 being the "we are
breaking backwards compatibility" release so we can fix the conf file,
the command line etc.
Thoughts?
I don't read the spec in the same way.
From the 0-9-1 Spec:
1.9.2.5. Method tx.rollback (ID 30)
This method abandons all message publications and acknowledgments
performed in the current
transaction. A new transaction starts immediately after a rollback.
Note that unacked messages will not be
automatically redelivered by rollback; if that is required an explicit
recover call should be issued.
I read that as the unacked messages will not be automatically given
back to the client. So we should put them back on the queue and let
the client fight it out with other cilents to see who gets them.
My understanding is that they would remain in the 'acquired' state, not
acked but not requeued. The client could then decide to call recover
explicitly to either requeue them or have them redelivered (or it could
simply replay them itself if held locally).
In 0-8/0-9 it was not explicitly stated that there should be a
recover(requeue=false) implied by rollback but we assumed this as the
spec did prohibit an explicit recover call for transactional sessions.
0-9-1 explicitly stated that the recover was not implied, but allowed
the recover to be called on a transactional session if desired.
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