Chris,
Thanks a lot for this, it's quite useful. We believe we're OK for a local failover, the scenario we're trying to cater for is a computer center outage. In this scenario we want to recover all messages using a hot DR site. The circular logs were chosen previously to ease housekeeping and archiving, the logs are sized at about 2Gb per QM so they should be big enough. We don't have very large volumes or message sizes going through the system.
Kulbir.
| "Christopher Warneke" <[EMAIL PROTECTED]>
Sent by: "MQSeries List" <[EMAIL PROTECTED]> 18-Nov-2004 06:47
|
To: MQSERIES cc: Subject: Re: Backing up "Q" files but not the "LOG" files |
Kulbir,
Persistent messages are written to the log, commited
- then written to the queues. Without the log files,
you risk losing inflight activity. Plain and simple.
If the messages are not persistent - who cares if you
loose them?
If you have a redundant hardware solution, 2nd
machine, mirrored DASD & UPS, you likely have a robust
enough configuration for all but total loss of the
computer center. If this outage would have you moving
operations to a DR site, how much inflight activity
are you trying to protect?
Given that you are running with circular logging, is
it really necessary to try to come up at the DR site
with all inflight activity recovered?
If this is the case, is this DR site "hot"? If not,
why wouldn't simple configuration backup suffice?
I suspect that you are wasting time trying to
nickle-and-dime a solution that will likely give you a
nasty suprise, should you be in the position of
needing the level of recovery that you are seeking.
That, or you don't really need to recover the
in-flight traffic.
Good luck,
Chris
--- "Kulbir S. Thind" <[EMAIL PROTECTED]> wrote:
> We're trying to ensure we don't lose messages in
> Disaster Recovery
> situations. Our failover solution seems OK, we have
> a SAN configured to
> hold all queue manager details and that is
> accessible by another machine
> in the Veritas cluster if we need to failover. For
> DR we're looking to
> use another machine that is based 3,000 miles away,
> for this we need to
> minimise the amount of data we replicate, hence the
> reason why we're
> contemplating on replicating just the Q files and
> not LOG files.
>
> Cheers.
>
>
>
>
> "Christopher Warneke"
> <[EMAIL PROTECTED]>
>
> Sent by: "MQSeries List" <[EMAIL PROTECTED]>
> 17-Nov-2004 20:26
> Please respond to "MQSeries List"
> <[EMAIL PROTECTED]>
>
>
>
> To: MQSERIES
>
> cc:
> Subject: Re: Backing up "Q" files but
> not the "LOG" files
>
>
> What I don't understand here, is the purpose of the
> replication. Are we trying to retain backups of the
> qmgr's objects, or both the objects and the
> messages?
>
> If you are only trying to retain copies of the
> objects...
>
>
http://www-306.ibm.com/software/integration/support/supportpacs/category.html#cat2
>
>
> MS03: WebSphere MQ - Save Queue Manager object
> definitions using PCFs
>
> Otherwise, investigate a mirrored DSAD solution, or;
> if you are using AIX, the HACMP supportpac...
>
> MC63: WebSphere MQ for AIX - Implementing with HACMP
>
> Maybe explain what your goal is, that has you trying
> this experiment. I'd like to understand what you
> are
> trying to accomplish.
> Thank you,
> Chris
>
> --- "Kulbir S. Thind" <[EMAIL PROTECTED]>
> wrote:
>
> > Hi,
> >
> > We're thinking about setting up replication for
> our
> > queue manager to
> > ensure that just the Q files are backed up but not
> > the LOG files for the
> > queue manager. This is being contemplated as it
> > appears the log files are
> > updated far more than the Q files as the LOG files
> > are doing internal
> > MQSeries checks, etc. We need to reduce the
> amount
> > of data that we're
> > replicating.
> >
> > My first thoughts on this were that this would not
> > work as the Q files
> > would be out of sync with the LOG files. However
> we
> > performed the
> > following:
> >
> > Created a queue manager
> > Started the queue manager
> > Created some queues
> > Put some message on the queues
> > Ended the queue manager
> > Took a copy of the LOG files used by the queue
> > manager
> > Started the queue manager
> > Put some more messages on the queues
> > Created another queue object
> > Ended the queue manager
> > Restored the LOG files that were backed up in step
> 6
> > Started the queue manager
> >
> > At this point I was expecting issues but I found
> > that the queue manager
> > started without problems and it recognised the
> queue
> > that was created in
> > step 9. Does this mean if we took a copy of the
> LOG
> > files and restored
> > them to a queue manager at a later point retaining
> > the latest Q files we
> > would have no problems? Has anyone tried this or
> no
> > of any problems?
> >
> > Cheers,
> >
> > Kulbir.
>
> Instructions for managing your mailing list
> subscription are provided in
> the Listserv General Users Guide available at
> http://www.lsoft.com
> Archive: http://vm.akh-wien.ac.at/MQSeries.archive
>
>
Instructions for managing your mailing list subscription are provided in
the Listserv General Users Guide available at http://www.lsoft.com
Archive: http://vm.akh-wien.ac.at/MQSeries.archive
