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| sdrazi |
 Posted: Fri Dec 14, 2012 9:00 am Post subject: Recover MQ data from logs - on different versions on MQ |
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Apprentice
Joined: 17 Apr 2007
Posts: 34
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Hello,
We are replacing our current AIX 5.3 box that has MQ 6.0 installed on it.
The new box has AIX 6.1 and the intent is to install MQ 7.5 on the new machine. The data for both resides on SAN
The old/current box is intended to be a cold spare.
My question is in the event of failure of the new box and messages being on the queues, is it possible to use the active logs on the new box to recover the state of MQ on the old box through manual steps.
Thanks for help in this regard. |
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| bruce2359 |
| Posted: Fri Dec 14, 2012 10:17 am Post subject: |
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Poobah
Joined: 05 Jan 2008
Posts: 9469
Location: US: west coast, almost. Otherwise, enroute.
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Circular or linear? What value would old logs be after one day, one week, one month, one year?
_________________
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. |
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| sdrazi |
| Posted: Fri Dec 14, 2012 10:44 am Post subject: |
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Apprentice
Joined: 17 Apr 2007
Posts: 34
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| linear - our standard has been one week for old logs (which does not include active logs) |
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| bruce2359 |
| Posted: Fri Dec 14, 2012 10:52 am Post subject: |
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Poobah
Joined: 05 Jan 2008
Posts: 9469
Location: US: west coast, almost. Otherwise, enroute.
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So, you keep old logs. Why? What purpose do they serve for your organization?
_________________
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. |
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| mqjeff |
| Posted: Fri Dec 14, 2012 10:58 am Post subject: |
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Grand Master
Joined: 25 Jun 2008
Posts: 17447
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| I do not recommend attempting to start a v6.0 queue manager with any files created by a 7.5 queue manager. |
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| Cressida |
| Posted: Fri Dec 14, 2012 11:31 am Post subject: |
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Disciple
Joined: 13 Jul 2007
Posts: 157
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And if one is looking for a professionally done and vendor supported tool for such things utilizing the MQ logs... consider Cressida ReQuest as a possible alternative solution.
It has served a good few folks wanting to replay and recover messages to & from different MQ versions, even between a few different OSs ....
Well worth some consideration  |
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| sdrazi |
| Posted: Fri Dec 14, 2012 1:25 pm Post subject: |
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Apprentice
Joined: 17 Apr 2007
Posts: 34
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We havent had to use old logs but my assumption was it could be used to replay old messages.
However, is there something that would say 6.0 logs are not compatible with 7.5?
if we do upgrade our old box to 7.5 as well what would be the process? copy the active logs over and start the queue manager on the cold backup?
Thanks |
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| mqjeff |
| Posted: Fri Dec 14, 2012 3:04 pm Post subject: |
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Grand Master
Joined: 25 Jun 2008
Posts: 17447
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If you upgrade your old box to 7.5, then you can do a number of things, including creating the queue manager as a backup qmgr.
It's reasonable to expect that a 7.5 qmgr can read log files and other files created by a v6.0 qmgr - this is part and parcel of the process of updating a qmgr.
It's unreasonable to expect the reverse. |
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| Cressida |
| Posted: Sat Dec 15, 2012 5:04 am Post subject: |
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Disciple
Joined: 13 Jul 2007
Posts: 157
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| sdrazi wrote: |
.......However, is there something that would say 6.0 logs are not compatible with 7.5?
if we do upgrade our old box to 7.5 ....... ? |
Depends how old is your old AIX box as not all old AIX boxes are much newer MQ version capable ..... first check on that.
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| mqjeff wrote: |
| ....It's unreasonable to expect the reverse. |
I suppose this is True for the base MQ , and yet sometimes 3rd party tolls can do the unreasonable .... Cressida ReQuest would handle this reversed case too.
Thanks |
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| bruce2359 |
| Posted: Sat Dec 15, 2012 7:13 am Post subject: |
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Poobah
Joined: 05 Jan 2008
Posts: 9469
Location: US: west coast, almost. Otherwise, enroute.
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| sdrazi wrote: |
| We haven't had to use old logs but my assumption was it could be used to replay old messages. |
How would you identify which message(s) need to be recovered? By date and time? By application? By something in the message data? What about the other messages that comprised the Unit of Work?
I'm not opposed to keeping logs, even forever; but you should have a proven method (program, procedure) in place to extract messages in the unlikely event you should need to do so.
_________________
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. |
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| mqjeff |
| Posted: Sat Dec 15, 2012 7:21 am Post subject: |
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Grand Master
Joined: 25 Jun 2008
Posts: 17447
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| Cressida wrote: |
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| mqjeff wrote: |
| ....It's unreasonable to expect the reverse. |
I suppose this is True for the base MQ , and yet sometimes 3rd party tolls can do the unreasonable .... Cressida ReQuest would handle this reversed case too. |
I endeavored to be careful in my wording in which I specified that it was the *queue manager* taking action. |
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| Andyh |
| Posted: Sat Dec 15, 2012 9:22 am Post subject: |
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Master
Joined: 29 Jul 2010
Posts: 239
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When a V.x (e.g V6) queue manager is migrated to V.x+n (e.g V7.1) the objects known to that queue manager are migrated to the V.x+n format at first reference.
With linear logging, images of the objects are stored in the logs, and for a V.y queue manager they will be stored in V.y format.
A V.x queue manager cannot understand the format of V.x+n objects and hence a V.x queue manager cannot successfully recover from the logs for a V.x+n queue manager.
Restoring specific queues based upon the message data in the logs might be possible with a third party tool, but it would be surprising if the whole queue manager could be recovered to a sensible state. For example in V7.5 there are log records related to multiple system cluster transmit queues which related to objects that don't even exist at V6.
If you want to use the old hardware as a cold standby, could you install a current (i.e supported) AIX version, and the matching MQ version on the cold standby ? |
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| sdrazi |
| Posted: Mon Dec 17, 2012 9:19 am Post subject: |
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Apprentice
Joined: 17 Apr 2007
Posts: 34
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I am in the process of figuring the hardware/software compatibility with our current box. I will also check with our account rep if having a backup queue manager incurs additional license.
Thanks for the tips.
Message recovery from old logs was thought of to be date/time based. |
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| fjb_saper |
| Posted: Tue Dec 18, 2012 3:54 am Post subject: |
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Grand High Poobah
Joined: 18 Nov 2003
Posts: 20756
Location: LI,NY
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| sdrazi wrote: |
I am in the process of figuring the hardware/software compatibility with our current box. I will also check with our account rep if having a backup queue manager incurs additional license.
Thanks for the tips.
Message recovery from old logs was thought of to be date/time based. |
Big misconception.... it never is. WMQ is a point of failure type recovery, not a point in time type recovery... 
_________________
MQ & Broker admin |
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| Cressida |
| Posted: Tue Dec 18, 2012 7:14 am Post subject: |
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Disciple
Joined: 13 Jul 2007
Posts: 157
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| fjb_saper wrote: |
| sdrazi wrote: |
.........
Message recovery from old logs was thought of to be date/time based. |
Big misconception.... it never is. WMQ is a point of failure type recovery, not a point in time type recovery... |
If I may please plug our little tool one more time ; Cressida ReQuest prides itself in being a 'Point-in-Time' WMQ Logs Message Reporter, Replay and Recovery tool.
Thank you. |
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