I think there's a subtle "middlepoint" here.

You may not have received an RC=0 on the commit, but the messages may have
been committed anyway. There would be a small window of opportunity where MQ
has completed the commit, but before it could return RC=0 to the app, it all
goes pear shaped.

I think the only guarantee is that either all the messages in the UOW will
be committed or all will be backed out. You will never be able to get a
situation where some of the messages in a UOW get committed and other in the
same UOW get backed out.

I've seen other threads talking about this with respect to MQClient and to
quote Paul Clarke:

"The semantics of messaging is exactly the same for a client as for a
locally connected application. In other words, in order to do reliable
messaging in a local application you must follow a certain set of rules like
issuing MQPUTs and MQGETs under transactions etc. These rules are exactly
the same for a client. One area which often concerns programmers is the
MQCMIT call. What happens if you lose your network half way through an
MQCMIT verb and get a MQRC_CONNECTION_BROKEN reason code. Did the
transaction commit or didn't it ? Well, this is the same for a local
application, you are not guaranteed to get a definitive answer on your
transaction commit even for the local application. If you really care, you
must do some 'known' action (like put a message to a queue) that you can
subsequently check the next time you connect."

Regards
John.

-----Original Message-----
From: Robert Broderick [mailto:[EMAIL PROTECTED]
Sent: 30 May 2003 15:28
To: [EMAIL PROTECTED]
Subject: Re: MQ behaviour - persistent messages availability when the qmgr
crashes


If you application didn't receive the RC=0 I believe it would be considered
an inflight transaction and would be backed out upon QMGR restart.


>From: Diwakar S Yammanuru <[EMAIL PROTECTED]>
>Reply-To: MQSeries List <[EMAIL PROTECTED]>
>To: [EMAIL PROTECTED]
>Subject: MQ behaviour - persistent messages availability when the qmgr
>         crashes
>Date: Fri, 30 May 2003 10:58:39 -0400
>
>Hello there.
>When an application puts a persistent msg on a queue and if the
>corresponding qmgr fails before the messge is committed/backed out
>..... can the message still be recovered after the qmgr comes up ? I
>mean, is the message logged ?
>
>Does a qmgr perform a commit/backout just before it crashes, if it is
>the transaction manager ?
>
>Forgive me if the questions sound silly.
>
>thnx.
>Diwakar.
>
>
>
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