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| AMQ7469 and lost messages? |
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| LouML |
 Posted: Mon Jan 28, 2008 5:53 am Post subject: |
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Partisan
Joined: 10 Nov 2005
Posts: 305
Location: Jersey City, NJ / Bethpage, NY
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| Vitor wrote: |
Is changing the number of logs like that supported now?
Back in my day, the number and type of logs was fixed at queue manager creation....  |
I certainly could be wrong but from what I'm reading in the System Administration Guide v5.3.12, the number of files (pri and sec) can be changed like this. The LogType, LogFilePages and LogBufferPages cannot be changed without recreating.
| Code: |
LogPrimaryFiles=3|2-62
The log files allocated when the queue manager is created. The minimum number of primary log files you can have is 2 and the maximum is 62. The default is 3. The total number of primary and secondary log files must not exceed 63, and must not be less than 3. The value is examined when the queue manager is created or started. You can change it after the queue manager has been created. However, a change in the value is not effective until the queue manager is restarted, and the effect might not be immediate.
LogSecondaryFiles=2|1-61
The log files allocated when the primary files are exhausted. The minimum number of secondary log files is 1 and the maximum is 61. The default number is 2. The total number of primary and secondary log files must not exceed 63, and must not be less than 3. The value is examined when the queue manager is started. You can change this value, but changes do not become effective until the queue manager is restarted, and even then the effect might not be immediate. LogFilePages=number The log data is held in a series of files called log files. The log file size is specified in units of 4 KB pages. In WebSphere MQ for UNIX systems, the default number of log file pages is 1024, giving a log file size of 4 MB. The minimum number of log file pages is 64 and the maximum is 16 384. In WebSphere MQ for Windows NT and Windows 2000, the default number of log file pages is 256, giving a log file size of 1 MB. The minimum number of log file pages is 32 and the maximum is 16 384.Note: The size of the log files specified during queue manager creation cannot be changed for a queue manager.
LogType=CIRCULAR|LINEAR
The type of logging to be used by the queue manager. You cannot change the type of logging to be used once the queue manager has been created. Refer to the description of the LogType attribute in “Log defaults for WebSphere MQ” on page 96 for information about creating a queue manager with the type of logging you require. CIRCULAR Start restart recovery using the log to roll back transactions that were in progress when the system stopped. See “Circular logging” on page 196 for a fuller explanation of circular logging. LINEAR For both restart recovery and media or forward recovery (creating lost or damaged data by replaying the contents of the log). See “Linear logging” on page 197 for a fuller explanation of linear logging.
LogBufferPages=0|0-512
The amount of memory allocated to buffer records for writing, specifying the size of the buffers in units of 4 KB pages. The minimum number of buffer pages is 18 and the maximum is 512. Larger buffers lead to higher throughput, especially for larger messages. If you specify 0 (the default), the queue manager selects the size. In WebSphere MQ V5.3 this is 64 (256 KB). If you specify a number between 1 and 17, the queue manager defaults to 18 (72 KB). If you specify a number between 18 and 512, the queue manager uses the number specified to set the memory allocated. The value is examined when the queue manager is created or started, and might be increased or decreased at either of these times. However, a change in the value is not effective until the queue manager is restarted. |
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| Vitor |
| Posted: Mon Jan 28, 2008 6:00 am Post subject: |
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Grand High Poobah
Joined: 11 Nov 2005
Posts: 26093
Location: Texas, USA
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| LouML wrote: |
| Vitor wrote: |
Is changing the number of logs like that supported now?
Back in my day, the number and type of logs was fixed at queue manager creation.... |
I certainly could be wrong but from what I'm reading in the System Administration Guide v5.3.12, the number of files (pri and sec) can be changed like this. The LogType, LogFilePages and LogBufferPages cannot be changed without recreating. |
Nope, it certainly does say that. Specifically it says:
| Quote: |
| The value is examined when the queue manager is created or started. You can change it after the queue manager has been created. However, a change in the value is not effective until the queue manager is restarted, and the effect might not be immediate. |
(My italics)
So I guess you need to be patient....
_________________
Honesty is the best policy.
Insanity is the best defence. |
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| LouML |
| Posted: Mon Jan 28, 2008 8:24 am Post subject: |
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Partisan
Joined: 10 Nov 2005
Posts: 305
Location: Jersey City, NJ / Bethpage, NY
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| Vitor wrote: |
| Quote: |
| The value is examined when the queue manager is created or started. You can change it after the queue manager has been created. However, a change in the value is not effective until the queue manager is restarted, and the effect might not be immediate. |
(My italics)
So I guess you need to be patient.... |
Still the same 5 files. Considering we've had this initial config for so long and this problem has only happened once, it may just be that the 5 files are enough for most days. I thought they were supposed to be created at restart but maybe they are only created as needed. I can't find an answer in the docs so I guess I'll just keep watching. |
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| jefflowrey |
| Posted: Mon Jan 28, 2008 8:51 am Post subject: |
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Grand Poobah
Joined: 16 Oct 2002
Posts: 19981
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I remember some notes from Nigelg on this - at some point. Unless I'm remembering wrong.
I think that they are created at crtmqm time and then as needed. Primaries are not deleted, but secondaries can be.
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I am *not* the model of the modern major general. |
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| LouML |
| Posted: Mon Jan 28, 2008 10:08 am Post subject: |
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Partisan
Joined: 10 Nov 2005
Posts: 305
Location: Jersey City, NJ / Bethpage, NY
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| jefflowrey wrote: |
I remember some notes from Nigelg on this - at some point. Unless I'm remembering wrong.
I think that they are created at crtmqm time and then as needed. Primaries are not deleted, but secondaries can be. |
Makes sense.
So basically, the 5 files are used as is, until the 6th is needed. Once that 6th is needed, it does not go away.
If at some time it needs more than the 20 files I have defined for Primary, the secondary file(s) gets created as needed. That file, will go away when no longer used.
If this is correct, this might be what we experienced (except that I never got to check to see my 3 secondary files existed). |
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| mvic |
| Posted: Tue Jan 29, 2008 5:01 pm Post subject: |
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Jedi
Joined: 09 Mar 2004
Posts: 2080
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| LouML wrote: |
| If this is correct, this might be what we experienced (except that I never got to check to see my 3 secondary files existed). |
If you want to experiment on a test queue manager to see the appearance of your secondary log files and an AMQ7469 message:
1. run an application that says MQCONN / MQOPEN / MQPUT(SYNCPOINT) / sleep(forever)
2. run an application that says MQCONN / MQOPEN / marker: / MQPUT(PERSISTENT MSG) / goto marker.
Alternatively, let MQ handle all of this and just believe it works  I assure you, it works.
If, after causing the transaction to rollback, app 1 later calls MQCMIT, it should get rejected with MQRC_BACKED_OUT. |
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| LouML |
| Posted: Wed Jan 30, 2008 4:46 am Post subject: |
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Partisan
Joined: 10 Nov 2005
Posts: 305
Location: Jersey City, NJ / Bethpage, NY
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| mvic wrote: |
| LouML wrote: |
| If this is correct, this might be what we experienced (except that I never got to check to see my 3 secondary files existed). |
If you want to experiment on a test queue manager to see the appearance of your secondary log files and an AMQ7469 message:
1. run an application that says MQCONN / MQOPEN / MQPUT(SYNCPOINT) / sleep(forever)
2. run an application that says MQCONN / MQOPEN / marker: / MQPUT(PERSISTENT MSG) / goto marker.
Alternatively, let MQ handle all of this and just believe it works I assure you, it works.
If, after causing the transaction to rollback, app 1 later calls MQCMIT, it should get rejected with MQRC_BACKED_OUT. |
As of this morning, I'm still only seeing the original 5 primary files, but I guess that's because we haven't reached the volume that would cause a 6th file to be created. I guess it would have been nice to see all 20 primary files created and empty, just to be sure.
I'm going to assume that MQ knows what it's doing. 
| Code: |
bash-2.05$ ls -la /MQHA/QM.jefomsapp.01/log/QM\!jefomsapp\!01/active
total 41042
drwxrwx--- 2 mqm mqm 1024 Jan 22 15:53 .
drwxrwx--- 3 mqm mqm 96 Jul 5 2005 ..
-rw-rw---- 1 mqm mqm 4202496 Jan 29 17:32 S0000000.LOG
-rw-rw---- 1 mqm mqm 4202496 Jan 30 07:08 S0000001.LOG
-rw-rw---- 1 mqm mqm 4202496 Jan 29 17:05 S0000002.LOG
-rw-rw---- 1 mqm mqm 4202496 Jan 30 07:14 S0000003.LOG
-rw-rw---- 1 mqm mqm 4202496 Jan 29 22:42 S0000004.LOG
bash-2.05$ |
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| LouML |
| Posted: Thu Feb 14, 2008 11:33 am Post subject: |
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Partisan
Joined: 10 Nov 2005
Posts: 305
Location: Jersey City, NJ / Bethpage, NY
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Finally, an update.
Just looked today and I see plenty of log files now. Looks like it's working. Now, I hope I don't run out of these!
| Code: |
bash-2.05$ ls -la /MQHA/QM.jefomsapp.01/log/QM\!jefomsapp\!01/active
total 155954
drwxrwx--- 2 mqm mqm 1024 Feb 11 16:00 .
drwxrwx--- 3 mqm mqm 96 Jul 5 2005 ..
-rw-rw---- 1 mqm mqm 4202496 Feb 14 14:18 S0000000.LOG
-rw-rw---- 1 mqm mqm 4202496 Feb 14 14:20 S0000001.LOG
-rw-rw---- 1 mqm mqm 4202496 Feb 14 14:17 S0000002.LOG
-rw-rw---- 1 mqm mqm 4202496 Feb 14 14:15 S0000003.LOG
-rw-rw---- 1 mqm mqm 4202496 Feb 14 14:19 S0000004.LOG
-rw-rw---- 1 mqm mqm 4202496 Feb 14 14:21 S0000005.LOG
-rw-rw---- 1 mqm mqm 4202496 Feb 14 14:22 S0000006.LOG
-rw-rw---- 1 mqm mqm 4202496 Feb 14 14:23 S0000007.LOG
-rw-rw---- 1 mqm mqm 4202496 Feb 14 14:25 S0000008.LOG
-rw-rw---- 1 mqm mqm 4202496 Feb 14 14:26 S0000009.LOG
-rw-rw---- 1 mqm mqm 4202496 Feb 14 14:27 S0000010.LOG
-rw-rw---- 1 mqm mqm 4202496 Feb 14 14:28 S0000011.LOG
-rw-rw---- 1 mqm mqm 4202496 Feb 14 14:28 S0000012.LOG
-rw-rw---- 1 mqm mqm 4202496 Feb 14 14:29 S0000013.LOG
-rw-rw---- 1 mqm mqm 4202496 Feb 14 14:30 S0000014.LOG
-rw-rw---- 1 mqm mqm 4202496 Feb 14 14:11 S0000015.LOG
-rw-rw---- 1 mqm mqm 4202496 Feb 14 14:12 S0000016.LOG
-rw-rw---- 1 mqm mqm 4202496 Feb 14 14:13 S0000017.LOG
-rw-rw---- 1 mqm mqm 4202496 Feb 14 14:14 S0000018.LOG
bash-2.05$ |
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