Paul,
Thanks, on the two platforms where use linear logging, we have
regular maintenance windows and that would be the time for this.
Don Thomas
EDS - PASC
* Phone: +01-412-893-1659
Fax: 412-893-1844
* mailto:[EMAIL PROTECTED]
-----Original Message-----
From: MQSeries List [mailto:[EMAIL PROTECTED] On Behalf Of Paul
Clarke
Sent: Tuesday, June 29, 2004 9:28 AM
To: [EMAIL PROTECTED]
Subject: Re: Fw: Why running rcdmqimg would free up linear log?
Don,
Issuing rcdmqimg regularly can reduce the number of log files MQ needs to
perform recovery. However, if you issue it too often, ie. hourly, then you
can get in the way of your applications. Exactly when to use the command
will depend on how keen you are on keep the logs to a minimum and what your
application messaging profile is. From a Queue Manager point of view the
best time to take a media image is when the queue is empty and there are no
'in-flight' messages.
Not sure how much that helps but I can't think of any more concrete advice
to give, Cheers, P.
Paul G Clarke
WebSphere MQ Development
IBM Hursley
MQSeries List <[EMAIL PROTECTED]> wrote on 29/06/2004 13:51:54:
> So just for my own clarity, when using linear logs, it appears
> as though it's a good idea to run rcdmqimg on regular basis, si?
>
> Don Thomas
> EDS - PASC
> * Phone: +01-412-893-1659
> Fax: 412-893-1844
> * mailto:[EMAIL PROTECTED]
>
>
>
> -----Original Message-----
> From: MQSeries List [mailto:[EMAIL PROTECTED] On Behalf Of Paul
> Clarke
> Sent: Tuesday, June 29, 2004 5:20 AM
> To: [EMAIL PROTECTED]
> Subject: Re: Fw: Why running rcdmqimg would free up linear log?
>
>
> John,
>
> I passed your question on to our logging expert here in Hursley and
> this
was
> his response.
>
> "It appears that the customer hasn't fully understood the concepts of
media
> recovery and checkpointing. The queue manager doesn't "release" old
> logs needed for media recovery. The queue manger identifies the logs
> needed to perform media recovery, if an old log is needed to perform
> media recovery and media images are taken of all objects then the old
> log should no
longer
> be required for media recovery and is thus eligible to be "released"
> by
the
> customer.
>
> Checkpointing is related to limiting the amount of log replay
> necessary
for
> restart recovery, it has almost nothing to do with media recovery."
>
> I hope that helps,
> Cheers,
> P.
>
> Paul G Clarke
> WebSphere MQ Development
> IBM Hursley
>
> > ----- Forwarded by Paul Clarke/UK/IBM on 29/06/2004 09:15 -----
> >
> > John Elgie <[EMAIL PROTECTED]>
> > Sent by: MQSeries List <[EMAIL PROTECTED]>
> >
> > 29/06/2004 00:59
> >
> > Please respond to
> > MQSeries List
> >
> > To
> >
> > [EMAIL PROTECTED]
> >
> > cc
> >
> > Subject
> >
> > Why running rcdmqimg would free up linear log?
> >
> > I am running a 5.3.0.5 qmgr on aix. We had a qmgr with linear logs
> > that was not releasing an old log that it needed for media recovery.
> > There were no outstanding transactions from dspmqtrn. Running
> > rcdmqimg -m qmgr -t all \* immediately released the old log for
> > media recovery. Support docs. specifically say the rcdmqimg does NOT
> > do log checkpointing. Is this a co-incidence? or is there another
> reason?
> > John Elgie
> > 8-3777 Kingsway, Burnaby, V5H 3Z7
> > Desk: (604)432-4675
> > Cell: (604)315-7940
>
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