ca.portal.admin

Re:Re: Dead locking Information

Discussion created by ca.portal.admin on Oct 17, 2005
Bill,
Most deadlocks these days are caused by ADSO retrieval locking which came into existence with release 12.0, around 1993 and has been causing grief ever since. Because CA thought they were fixing a bug and not adding a new feature, they did not publish the change, at first. I've attached some information from the current ADS manual about it and also a program I wrote to extract all dialogs from the dictionaary with the retrieval locking indicator and whether the dialog is update or retrieval only. It's very crude and puts the records into a file so they can be sorted or downloaded to a spreadsheet. The list will also indicate whether the dialog links or invokes another dialog. The first thing you can do, is turn retrieval locks off for all dialogs which are retrieval only and don't link to other dialogs. Also, monitor the log for deadlocks because often it is only a few dialogs causing the problem. Look for errors of ""0361"" or ""0306"". Another thing that happens with retrieval locking deadlocks is that the dialog run unit terminates and then starts up again at the next DML command. This is what causes the ""0306""s because currency has been lost. If the problem dialogs are update dialogs, that are linked to from another dialog, you will want to try and isolate the update functions as much as possible, by putting them in mapless dialogs, passing DBKEYS for them to re-establish currency and using the LINK NOSAVE option to execute them. If you can give me a scenario you're dealing with, I can give you more specifics on how to handle it. Let me know if you have any questions on this and good luck!
Margaret


-----Original Message-----
From: Bill Allen [mailTo:ARCHCONB@AOL.COM]
Sent: Friday, October 14, 2005 10:32 PM
To: IDMS-L@LISTSERV.IUASSN.COM
Subject: Dead locking Information

Hello All:

Anyone have any tips, tricks, techniques, documentation, white papers or CA
World Presentations on Dead Locking?

I would be grateful if you would share them with me. I already have the CA
World 2004 Presentations.

Bill Allen
"
IDMS Public Discussion Forum
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IDMS-L@LISTSERV.IUASSN.COM
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Re: Dead locking Information
"Bill,
Most deadlocks these days are caused by ADSO retrieval locking which came into existence with release 12.0, around 1993 and has been causing grief ever since. Because CA thought they were fixing a bug and not adding a new feature, they did not publish the change, at first. I've attached some information from the current ADS manual about it and also a program I wrote to extract all dialogs from the dictionaary with the retrieval locking indicator and whether the dialog is update or retrieval only. It's very crude and puts the records into a file so they can be sorted or downloaded to a spreadsheet. The list will also indicate whether the dialog links or invokes another dialog. The first thing you can do, is turn retrieval locks off for all dialogs which are retrieval only and don't link to other dialogs. Also, monitor the log for deadlocks because often it is only a few dialogs causing the problem. Look for errors of ""0361"" or ""0306"". Another thing that happens with retrieval locking deadlocks is that the dialog run unit terminates and then starts up again at the next DML command. This is what causes the ""0306""s because currency has been lost. If the problem dialogs are update dialogs, that are linked to from another dialog, you will want to try and isolate the update functions as much as possible, by putting them in mapless dialogs, passing DBKEYS for them to re-establish currency and using the LINK NOSAVE option to execute them. If you can give me a scenario you're dealing with, I can give you more specifics on how to handle it. Let me know if you have any questions on this and good luck!
Margaret


-----Original Message-----
From: Bill Allen [mailTo:ARCHCONB@AOL.COM]
Sent: Friday, October 14, 2005 10:32 PM
To: IDMS-L@LISTSERV.IUASSN.COM
Subject: Dead locking Information

Hello All:

Anyone have any tips, tricks, techniques, documentation, white papers or CA
World Presentations on Dead Locking?

I would be grateful if you would share them with me. I already have the CA
World 2004 Presentations.

Bill Allen
"
IDMS Public Discussion Forum
IDMS-L@LISTSERV.IUASSN.COM
SMTP
IDMS-L@LISTSERV.IUASSN.COM
IDMS-L@LISTSERV.IUASSN.COM
SMTP








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Re: [IDMSVENDOR-L] Dead locking Information
"the 1986 presentation / movie sound like a good place to start - but
remember the entire deadlock detection mechanism has changed since then -
in 10.2, deadlock detection was pro-active (every request was checked to
see if it ""closed the loop""), while in 12.0 and above, it is now
re-actively checked (hence the deadlock detection interval in the sysgen).

(the above is subject to my failing memory)

Chris Hoelscher
IDMS & DB2 Database Administrator
Humana Inc
502-580-2538
choelscher@humana.com




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Re: Dead locking Information
"Excellent presentation by Don, but you gotta see the movie! (Expert
series)

Scott J. Brady
Holland America Line

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