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| ggv |
 Posted: Thu Mar 29, 2007 1:32 am Post subject: how to start queue manager when logs are deleted? |
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Newbie
Joined: 29 Mar 2007
Posts: 6
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| Is a way to 'reinitialize' logs and start queue manager? |
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| HubertKleinmanns |
| Posted: Thu Mar 29, 2007 1:37 am Post subject: |
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Shaman
Joined: 24 Feb 2004
Posts: 732
Location: Germany
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Create another QMgr with the same log attributes as the corrupted one and move the directory active and the file amqhlctl.lfh from the log directory of the new QMgr to the log directory of the corrupted QMgr.
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Hubert |
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| ggv |
| Posted: Thu Mar 29, 2007 1:49 am Post subject: |
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Newbie
Joined: 29 Mar 2007
Posts: 6
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thank you, it works.
I expected queue manager creates new log files and writes warning messages... |
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| HubertKleinmanns |
| Posted: Thu Mar 29, 2007 2:08 am Post subject: |
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Shaman
Joined: 24 Feb 2004
Posts: 732
Location: Germany
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| ggv wrote: |
thank you, it works.
I expected queue manager creates new log files and writes warning messages... |
You now have created empty log files and most liekely you have lost some logging information, but MQ is able, to create new log entries for its future activities.
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Hubert |
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| ggv |
| Posted: Thu Mar 29, 2007 2:17 am Post subject: |
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Newbie
Joined: 29 Mar 2007
Posts: 6
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I did not lose anything - it was just a test, we here asked ourselves, what would happen if we lose log files?
It might happen, so what will do queue manager.
Now we know - it would not start.
I'd prefer to get a lot of error messages in console and error log file, but queue manager should start.......
Am I wrong with my wishes?
What is the reason do not start? |
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| HubertKleinmanns |
| Posted: Thu Mar 29, 2007 2:27 am Post subject: |
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Shaman
Joined: 24 Feb 2004
Posts: 732
Location: Germany
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| ggv wrote: |
I did not lose anything - it was just a test, we here asked ourselves, what would happen if we lose log files?
It might happen, so what will do queue manager.
Now we know - it would not start.
I'd prefer to get a lot of error messages in console and error log file, but queue manager should start.......
Am I wrong with my wishes?
What is the reason do not start? |
Yes, you are wrong. The most important files of a QMgr are the logs. For example, persistent messages are stored in the log, when they arive on the QMgr. If a QMgr cannot log a persistent message (e. g. message too big, log full), it won't accept this message.
Other things are also stored into the logs. Logs in MQ are similar too redo logs in Oracle databases - and very important.
Q files are only needed, when message canot be handled in the memory of the system - even persistent messages!
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Hubert |
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| ggv |
| Posted: Thu Mar 29, 2007 2:34 am Post subject: |
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Newbie
Joined: 29 Mar 2007
Posts: 6
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ok, agree.
But when we endmqm, all messages should be written to queues, should not?
if should, then why can not queue manager recreate log files? |
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| HubertKleinmanns |
| Posted: Thu Mar 29, 2007 2:45 am Post subject: |
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Shaman
Joined: 24 Feb 2004
Posts: 732
Location: Germany
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| ggv wrote: |
ok, agree.
But when we endmqm, all messages should be written to queues, should not?
if should, then why can not queue manager recreate log files? |
MQ works the other way round. A QMgr restores the q contents from the logs. When you use linear logging, you are able to recreate deleted Q files (so called media recovery). With linear logging you are only able, to recover the states of messages in queues (commited or not).
And - as I told you and you did - it is possible, to recreate the logs  .
But, because the logs are the most relevant data store, the recovery of the logs may loose messages. The philosophy of MQ is, not to loose (or duplicate) any message. And so actions like the recovery of logs (or committing an INDOUBT channel etc.) are not done by MQ itself, but by an operator. So MQ is not responsible for the (lost or duplicated) messages  !
The operator should be aware, that the actions above may lead to lost or duplicated messages and check manually or inform the corresponding application persons  .
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Hubert |
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| ggv |
| Posted: Thu Mar 29, 2007 4:03 am Post subject: |
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Newbie
Joined: 29 Mar 2007
Posts: 6
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got it. It's a strategic point. MQ won't do any actions which might delete messages.
An administrator can od it himself. |
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| bruce2359 |
| Posted: Thu Mar 29, 2007 5:45 am Post subject: |
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Guest
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Please read the MQ V6 System Administration Guide, especially recovery and restart, and managing logs. It will explain the purpose and use of the logs by MQ. It is critical that you understand logs and manage them appropriately.
MQ uses DB2s logging infrastructure; and like DB2, MQ will not start with missing or inconsistent logs. |
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| JonB |
| Posted: Thu Mar 29, 2007 6:36 am Post subject: |
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Apprentice
Joined: 14 Nov 2002
Posts: 27
Location: Dublin, Ireland
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If you are working on a distributed platform have a look at the Support Pac MO73. It is a very good script for maintaining linear logs. It will delete any logs no longer needed. You should possibly use it in conjunction with the rcdmqimg command.
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Jon Barry
IBM Certified System Administrator - WebSphere MQ V5.3
IBM Certified Solution Designer - WebSphere MQ V5.3 |
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| ggv |
| Posted: Thu Mar 29, 2007 9:50 pm Post subject: |
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