VSAM file Contention Error

jothibso · New User Joined: 03 Sep 2009 Posts: 18 Location: chennai

Hi,

I have two jobs JOBA job is updating the VSAM file and at the same time the other job JOBB is trying to delete and redefine the same VSAM file. Hence JOBB is abending due to file contention.

I had an option to change the scheduling for the JOBB by including negative dependency, But I was not advised to do so.

Can anyone advice me how to avoid this kind of VSAM file contention without a scheduling change?

expat · Posted: Tue Nov 16, 2010 12:31 pm

Unless you can come up with some magical formula for being able to delete and define a file that is held by another job, then the schedule change is the only way.

enrico-sorichetti · Posted: Tue Nov 16, 2010 12:31 pm

mission impossible!

I just wonder,
why waste resources to update a dataset which is going to be deleted right away

Robert Sample · Posted: Tue Nov 16, 2010 5:35 pm

Add a DD statement to the job pointing to the VSAM file with DISP=OLD.

jothibso · New User Joined: 03 Sep 2009 Posts: 18 Location: chennai

Hi Robert,

I added a Dummy sort step for copying the VSAM file(with DISP=OLD) to the temp dataset before the delete step. Also I Opened the VSAM file edit mode. My job didn't abend and it was waiting for the dataset, once i came out of the file, the job ran fine.

Thanks for your advise.

Robert Sample · Posted: Tue Nov 16, 2010 8:11 pm

The IDCAMS step doing the delete / define could have a DD statement pointing to the VSAM file -- it doesn't have to be copied or anything else; the DISP=OLD is the critical thing to have on the DD statement.

But glad to hear it's working!

expat · Posted: Tue Nov 16, 2010 8:33 pm

Mmmmmmmmmmm, I still believe that the professional approach would be to amend the schedule rather than some sticky tape and brown paper fix.

No offence meant towards Robert, after all it was what the OP requested.

Robert Sample · Posted: Tue Nov 16, 2010 8:42 pm

True, expat -- changing the schedule would be the preferred way to fix things!

dick scherrer · Posted: Tue Nov 16, 2010 9:52 pm

Hello,

And if the update runs for 4 hours, there are 2 initiators tied up . . .

Many data centers will not let a job "hang around" waiting for a dataset. The waiting job would be canceled and a nasty-gram sent to those responsible for the jobs.