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| rglack10 |
 Posted: Thu Sep 08, 2011 1:39 am Post subject: Multi-Instance QM with NFS (File locking issue) |
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Apprentice
Joined: 06 Jul 2011
Posts: 34
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Hi,
We are attempting to create multi-instance queue manager using NFSv4 mounted share on 2 nodes, one holding active and one holding passive instance of QM.
The mounting of NFS appears OK and is visible on both MQ nodes. The installation of QM as active and passive works ok and dspmq -x on each node shows active and passive versions.
However, when we perform any commands (runmqsc) on QM or try to fail over using endmqm -s etc it takes a very very long time. The AMQ/FDC logs show errors such as:
AMQ7279: WebSphere MQ queue manager 'TESTMQ1' lost ownership of data lock.
AMQ7259: WebSphere MQ queue manager '' could not obtain data lock.
indiciating file lock issues on NFS server. Also when we run the test commands amqmfsck it seems if we wait the passive instance of the file system acquires the lock even though we have not released the lock on the active node and we again see the errors above in the log..
I can't seem to find any previous posts specific to this... It could be an NFS issue which we are invetsigating at the moment. We have double checked the process and mounted/created many QM's to repeat the process and reduce human error but same problem.
Has anyone encountered this before? |
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| zpat |
| Posted: Thu Sep 08, 2011 2:14 am Post subject: |
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Jedi Council
Joined: 19 May 2001
Posts: 5866
Location: UK
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| Platform? Exact version of MQ? |
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| rglack10 |
| Posted: Thu Sep 08, 2011 4:19 am Post subject: |
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Apprentice
Joined: 06 Jul 2011
Posts: 34
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| zpat wrote: |
| Platform? Exact version of MQ? |
having looked at the NFS side, the installation was NFS v2/3 and not v4 as specified..
Problem resolved. |
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| mqjeff |
| Posted: Thu Sep 08, 2011 4:22 am Post subject: |
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Grand Master
Joined: 25 Jun 2008
Posts: 17447
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This is pretty close to PMR country, presumably you're following that track in parallel.
I might try enabling tracing on amqmfsck - or at least enabling tracing on everything and then only reporting on the output from amqmfsck. It might give you an idea of why the lock is available.
I've also seen a technote somewhere that had some more details about file locks and NFS and etc., but my brain is really not up to finding it this morning. |
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| rglack10 |
| Posted: Thu Sep 08, 2011 4:25 am Post subject: |
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Apprentice
Joined: 06 Jul 2011
Posts: 34
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| mqjeff wrote: |
This is pretty close to PMR country, presumably you're following that track in parallel.
I might try enabling tracing on amqmfsck - or at least enabling tracing on everything and then only reporting on the output from amqmfsck. It might give you an idea of why the lock is available.
I've also seen a technote somewhere that had some more details about file locks and NFS and etc., but my brain is really not up to finding it this morning. |
Thanks for the response.. We looked at everything in great detail except took for granted we were handed NFS v4 as this was a provided service and we had specified NFS v4 in the build requirements... doh. |
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| mqjeff |
| Posted: Thu Sep 08, 2011 4:35 am Post subject: |
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Grand Master
Joined: 25 Jun 2008
Posts: 17447
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| rglack10 wrote: |
| mqjeff wrote: |
This is pretty close to PMR country, presumably you're following that track in parallel.
I might try enabling tracing on amqmfsck - or at least enabling tracing on everything and then only reporting on the output from amqmfsck. It might give you an idea of why the lock is available.
I've also seen a technote somewhere that had some more details about file locks and NFS and etc., but my brain is really not up to finding it this morning. |
Thanks for the response.. We looked at everything in great detail except took for granted we were handed NFS v4 as this was a provided service and we had specified NFS v4 in the build requirements... doh. |
woo. Guess someone owes you a few beers...  Yes, NFS before V4 doesn't support reliable file locking...
Your response came in while I was typing my message. |
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