| Author |
Message
|
| someonesumit |
 Posted: Wed Feb 23, 2011 11:17 pm Post subject: Any side effect of Reading qmgr log "/var/mqm/log/QM/*& |
 |
|
Novice
Joined: 18 Sep 2009
Posts: 16
|
Hi,
I would like to know, Is there any effect on queue manager if we read queue manager logs (/var/mqm/log/QM1/*) or take a backup when the queue manager is running?
Need Advice.
Thanks |
|
| Back to top |
|
 |
| exerk |
| Posted: Thu Feb 24, 2011 1:32 am Post subject: |
|
|
Jedi Council
Joined: 02 Nov 2006
Posts: 6339
|
You should not be 'reading' the logs, period! As a general observation, any copy of an 'in-flight' file is going to produce a fuzzy back-up at best. Read the manual, it's all in there.
_________________
It's puzzling, I don't think I've ever seen anything quite like this before...and it's hard to soar like an eagle when you're surrounded by turkeys. |
|
| Back to top |
|
|
| someonesumit |
| Posted: Thu Feb 24, 2011 1:54 am Post subject: |
|
|
Novice
Joined: 18 Sep 2009
Posts: 16
|
Thanks for the reply!
Can you please guide me for the manual, I would like to go through it.
The thing I wanted to know, What would be the effect if we take backup of MQ log files in UNIX if queue manager is running.
Thanks |
|
| Back to top |
|
|
| exerk |
| Posted: Thu Feb 24, 2011 2:30 am Post subject: |
|
|
Jedi Council
Joined: 02 Nov 2006
Posts: 6339
|
| someonesumit wrote: |
| ...Can you please guide me for the manual, I would like to go through it... |
The Information Centre is searchable.
| someonesumit wrote: |
| ...The thing I wanted to know, What would be the effect if we take backup of MQ log files in UNIX if queue manager is running... |
Re-read my second sentence above.
_________________
It's puzzling, I don't think I've ever seen anything quite like this before...and it's hard to soar like an eagle when you're surrounded by turkeys. |
|
| Back to top |
|
|
| bruce2359 |
| Posted: Thu Feb 24, 2011 5:37 am Post subject: |
|
|
Poobah
Joined: 05 Jan 2008
Posts: 9469
Location: US: west coast, almost. Otherwise, enroute.
|
| Quote: |
| I would like to know, Is there any effect on queue manager if we read queue manager logs (/var/mqm/log/QM1/*) |
No effect.
| Quote: |
| or take a backup when the queue manager is running? |
No effect.
The queue managers use of logs, and how to manage them, is described in the WMQ System Administration manual - which is easily downloaded from IBM.
What are you going to use these backups for?
_________________
I like deadlines. I like to wave as they pass by.
ב''ה
Lex Orandi, Lex Credendi, Lex Vivendi. As we Worship, So we Believe, So we Live. |
|
| Back to top |
|
|
| gbaddeley |
| Posted: Thu Feb 24, 2011 2:39 pm Post subject: Re: Any side effect of Reading qmgr log "/var/mqm/log/Q |
|
|
Jedi Knight
Joined: 25 Mar 2003
Posts: 2538
Location: Melbourne, Australia
|
| someonesumit wrote: |
| I would like to know, Is there any effect on queue manager if we read queue manager logs (/var/mqm/log/QM1/*) or take a backup when the queue manager is running? |
There is no effect on the qmgr operation if some other process reads the logs, provided it doesn't lock out the qmgr from opening the log file for write. There might be a performance hit. Why do you want to read the logs?
You can take a backup of the logs while the qmgr is running, but the backup is completely useless. The logs are being continuously updated by the qmgr with in-flight transaction and recovery data, so the backup will not capture the logs in a consistent state. If you try to restore the logs there is a 99% chance that the qmgr will not be able to start.
A proper backup can only be taken of a qmgr when it is down.
_________________
Glenn |
|
| Back to top |
|
|
| someonesumit |
| Posted: Thu Feb 24, 2011 10:44 pm Post subject: |
|
|
Novice
Joined: 18 Sep 2009
Posts: 16
|
I found the below comment in MQ V7 manual:
/var/mqm/log/qmname/ contains the queue manager log files. The directory is locked for exclusive access by the active queue manager instance. The directory path is modifiable in the qm.ini file, or by using the ld option of the crtmqm command.
The term "Directory is locked for exclusive access by the active queue manager" signifies that we should not be using mq logs when the queue manager is running. In case of linear we can take media image and after finding the correct inactive logs we can delete. But in case of Circular as in my case , we shouldn't open or take backup of mq logs.
| Quote: |
| Why do you want to read the logs? |
In my project , there were some member information is passing through MQ. And the information is coming from another vender. Some where the member is missing either in sender end or in receiver end , not in MQ , since I am 100% sure messages never lost in MQ range.
So for debugging purpose, I saw the message in mq logs as the same it is being transferred. |
|
| Back to top |
|
|
| mqjeff |
| Posted: Fri Feb 25, 2011 5:11 am Post subject: |
|
|
Grand Master
Joined: 25 Jun 2008
Posts: 17447
|
| someonesumit wrote: |
| So for debugging purpose, I saw the message in mq logs as the same it is being transferred. |
The sponsor of this forum has a product in this area.
otherwise look at things like supportPac MA0Z or other such. And review all of the previous discussions on auditing message content.
Even if you have backup copies of the log files, they are in an internal and undocumented format and so you can't use them to show what you want to show. |
|
| Back to top |
|
|
| bruce2359 |
| Posted: Fri Feb 25, 2011 6:44 am Post subject: |
|
|
Poobah
Joined: 05 Jan 2008
Posts: 9469
Location: US: west coast, almost. Otherwise, enroute.
|
| Quote: |
| So for debugging purpose, I saw the message in mq logs as the same it is being transferred. |
Persistent messages are logged when put to a queue by the receiving MCA. So, the presence of a message in the logs does not mean that it was processed and forwarded out of your qmgr.
_________________
I like deadlines. I like to wave as they pass by.
ב''ה
Lex Orandi, Lex Credendi, Lex Vivendi. As we Worship, So we Believe, So we Live.
Last edited by bruce2359 on Sat Feb 26, 2011 12:18 pm; edited 1 time in total |
|
| Back to top |
|
|
| someonesumit |
| Posted: Fri Feb 25, 2011 10:17 pm Post subject: |
|
|
Novice
Joined: 18 Sep 2009
Posts: 16
|
persistence messages will get logged into mq logs only after that it will be stored in the queue. So if there are no messages in the queue, then it signifies messages have been processed by the application , there is not doubt in this.
But after messages got processed, we can see the messages in the logs also. |
|
| Back to top |
|
|
| someonesumit |
| Posted: Fri Feb 25, 2011 10:19 pm Post subject: |
|
|
Novice
Joined: 18 Sep 2009
Posts: 16
|
| Thanks for the information buddy! regarding MA0Z support pack. |
|
| Back to top |
|
|
| bruce2359 |
| Posted: Sat Feb 26, 2011 7:20 am Post subject: |
|
|
Poobah
Joined: 05 Jan 2008
Posts: 9469
Location: US: west coast, almost. Otherwise, enroute.
|
| Quote: |
| So if there are no messages in the queue, then it signifies messages have been processed by the application , there is not doubt in this. |
Not true.
What if the message ends up in the DLQ instead of the application queue?
What if the message expires?
What if another application consumes the message?
WMQ cannot guarantee that a message is delivered to the appropriate application queue. WMQ cannot guarantee that a message is consumed and appropriately processed by an application. There is no doubt in this.
_________________
I like deadlines. I like to wave as they pass by.
ב''ה
Lex Orandi, Lex Credendi, Lex Vivendi. As we Worship, So we Believe, So we Live. |
|
| Back to top |
|
|
| PeterPotkay |
| Posted: Sat Feb 26, 2011 8:16 am Post subject: |
|
|
Poobah
Joined: 15 May 2001
Posts: 7722
|
And what if the message was never successfully put (and committed) in the first place?
Just because the sending app says they did, does not make it so.
_________________
Peter Potkay
Keep Calm and MQ On |
|
| Back to top |
|
|
| someonesumit |
| Posted: Sat Feb 26, 2011 9:03 am Post subject: |
|
|
Novice
Joined: 18 Sep 2009
Posts: 16
|
| Quote: |
| What if the message ends up in the DLQ instead of the application queue? |
There are scenarios for message getting into DLQ, it will not go to DLQ just like that.
| Quote: |
| What if the message expires? |
There is no expiry in my case.
| Quote: |
| What if another application consumes the message? |
This depends how you configure your application and in my case the queue I wanted to monitor for messages is only accesses by single application.
| Quote: |
| WMQ cannot guarantee that a message is delivered to the appropriate application queue. WMQ cannot guarantee that a message is consumed and appropriately processed by an application. There is no doubt in this. |
For message to be delivered to appropriate application, it can be configured which application can use what queue. |
|
| Back to top |
|
|
| someonesumit |
| Posted: Sat Feb 26, 2011 9:05 am Post subject: |
|
|
Novice
Joined: 18 Sep 2009
Posts: 16
|
| Quote: |
| And what if the message was never successfully put (and committed) in the first place? |
If a message was never successfully put , then it will not come to the receiving end. |
|
| Back to top |
|
|
|
|
