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| Vitor |
 Posted: Thu Mar 15, 2007 6:08 am Post subject: Re: Backup queue Manager setup |
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Grand High Poobah
Joined: 11 Nov 2005
Posts: 26093
Location: Texas, USA
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| yortch wrote: |
| Assuming it is acceptable to lose that bit... |
Bad assumption. Do not mess with a file the queue manager is using. Depending on platform, operation in progress and how lucky you are, a variety of bad things will happen. At best you'll have an inconsistent backup that won't restore your queue manager properly.
As to your other point, it depends on how close to "now" you want your recovery to be. This also hinges on what your message throughput is; a factor on how fast log files are used you see.
I think the best thing here is to examine the business requirement. If there's a strong requirement for 24*7 availability and point-in-time recovery then you/they should spend the money on a proper HA solution, not piece together a solution on the cheap. If as is often the case the business want 24*7 availability because it sounds cool, find when they're not using it (I find 3.30 am a common time) and script a queue manager down-and-up to take a consistent backup. Literally takes 10 minutes.
Another solution you could try (and I've not thought this through particually) is to have 2 clustered queue managers, suspend one, stop it, back it up, start it, replace it, then repeat the process with the other one. Message processing can therefore continue while backups are being taken.
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Insanity is the best defence.
Last edited by Vitor on Thu Mar 15, 2007 7:02 am; edited 1 time in total |
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| yortch |
| Posted: Thu Mar 15, 2007 6:55 am Post subject: |
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Apprentice
Joined: 30 Aug 2004
Posts: 34
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Let me paraphrase my assumption by quoting the MQ system administration guide:
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| The existing queue manager does not need to be stopped for log files to be copied, however you should only copy a log file if the queue manager has finished writing to it. Because the existing queue manager log is continually updated, there is always a slight discrepancy between the existing queue manager log and the log data copied to the backup queue manager log. |
What I mean when I said it was "ok to lose that bit" was that the "slight discrepancy" is acceptable. I'm just trying to figure out which log files should be copied. I wished this feature was documented better. I have contacted IBM Support about this, it is just taking forever. If I get more info I will post it back here.
The customer is actually moving away from a HA (MSCS clustered) environment (long story). They have very unpredictable traffic, so even a 10 minute window may not work.
Thanks for the input. |
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| Vitor |
| Posted: Thu Mar 15, 2007 6:58 am Post subject: |
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Grand High Poobah
Joined: 11 Nov 2005
Posts: 26093
Location: Texas, USA
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| yortch wrote: |
| The customer is actually moving away from a HA (MSCS clustered) environment (long story). They have very unpredictable traffic, so even a 10 minute window may not work. |
Then they need to accept that as part of the movement away from HA their uptime may take a hit.
As to IBM Support, remember this feature is new for v6 so there may be some issues, like long response times on questions. Or problems with the new-fangled software..... 
I look forward to hearing how it works out for you. 
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Honesty is the best policy.
Insanity is the best defence. |
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| markt |
| Posted: Thu Mar 15, 2007 9:19 am Post subject: |
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Knight
Joined: 14 May 2002
Posts: 512
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| Read the Monitoring MQ book - it describes the event messages generated by the logger as logfiles are finished with. |
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| kevinf2349 |
| Posted: Thu Mar 15, 2007 11:39 am Post subject: |
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Grand Master
Joined: 28 Feb 2003
Posts: 1311
Location: USA
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| markt wrote: |
| Read the Monitoring MQ book - it describes the event messages generated by the logger as logfiles are finished with. |
Are you sure that isn't just for for the AMQERRxx logs?
I was under the impression that they are actually discussing the MQ log (Snnnnnnn.LOG) files where MQ keeps it actual messages etc.?
I could be wrong though......it has been known  |
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| jefflowrey |
| Posted: Thu Mar 15, 2007 11:45 am Post subject: |
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Grand Poobah
Joined: 16 Oct 2002
Posts: 19981
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The logger generates PCF Event Messages, that are documented in the manual that MarkT mentions.
At least some of these event messages also get written to AMQERR01.log, in order to allow someone to identify which Snnnnnn.log files are no longer needed.
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| kevinf2349 |
| Posted: Thu Mar 15, 2007 12:30 pm Post subject: |
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Grand Master
Joined: 28 Feb 2003
Posts: 1311
Location: USA
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| Aha...I see. Makes sense. Thanks |
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| yortch |
| Posted: Mon Mar 19, 2007 12:29 pm Post subject: |
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Apprentice
Joined: 30 Aug 2004
Posts: 34
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The information I received from IBM support regarding how to determine which log files to copy for updating the backup queue manager:
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C:\>echo dis qmstatus CURRLOG | runmqsc QM
AMQ8705: Display Queue Manager Status Details.
QMNAME(QM) STATUS(RUNNING)
CURRLOG(S0000024.LOG)
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The log files that need to be copied are all the ones with a number less than the current log extent. In the example above 000000 through 0000023 |
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