-911 Deadlock

sendhilkumaran · New User Joined: 15 Apr 2010 Posts: 8 Location: chennai

Hi Experts!

Previously, I had a CICS programs which inturns calls lot of CICS programs. The sequence goes like this

A --> B --> C --> D

Now I have changed the main CICS, say A program into a Stored procedure. I have used EXCI to call the cics online programs from this SP.

Now the call from A --> B is working fine but I am getting sqlcode -911 in the sub-program C while performing select operation on a table, say TABLE1. This table TABLE1 is used in the first called cics program B.

I assume the first called cics program B establishes exclusive lock on the tables. Becuase of this, sub-programs, C and D are getting -911.

Please suggest me how to remove this exclusive lock, if my assumption is right? Or give me a right direction?

Please fidn below the db2 log below:

dick scherrer · Posted: Mon Nov 29, 2010 9:59 pm

Hello,

It appears that you have a timeout rather than a deadlock.

You may need to change the design because A or B is locking something for too long. This will surely happen if A or B locks something that either C or D needs to lock also.

sendhilkumaran · New User Joined: 15 Apr 2010 Posts: 8 Location: chennai

Thanks for your reply, Dick!

Actually, the program B performs a SELECT operation "WITH UR " on the table TABLE1 and I feel this should not lock the table. The program times out when the program C tries to perform SELECT operation on the same table TABLE1.

I was just wondering why an select operation with ur is putting a lock on that table.

I can see the CICS thread which holds this table is the same which is due to the miror program DFHMIRS which is used as shipment program to call CICS program from a stored procedure here.

Could anybody let me know what would be the isolation level for the mirror program DFHMIRS in general?

GuyC · Posted: Tue Nov 30, 2010 3:56 pm

Programs that call eachother, run in the same Logical Unit of Work. No way they can lock eachother out.
Only if you have the same program/transaction concurrent you might get locks.

But according to the message it is a Distributed call (plan=DISTSERV) that locks the data : PPQRCST:UTDIDAPP02:pxyzcst:dllhost.exe