Cobol: Random Read Error in Production

mainframesguru · New User Joined: 24 Jun 2005 Posts: 36 Location: Hyderabad

Hi All,

I encountered a peculiar scenario in production.
A program tried reading a record randomly (KSDS file)
and it abended with 'Record not found - File status 23'.
But the record is present in the file.

When the job was rerun, without making any changes to data,
job ran successfully.

This issue occurs rarely, but certainly it require a fix.
Can anyone share their thoughts on it?

Please note, that it is a daily executed job.

Regards
Vamshi

CICS Guy · Posted: Wed Sep 24, 2008 4:29 pm

Was the dataset open to another region, such as a CICS?

mainframesguru · New User Joined: 24 Jun 2005 Posts: 36 Location: Hyderabad

Dataset was NOT open to other regions.
It was Closed Disabled in CICS region.

Regards
vamshi

Cristopher · New User Joined: 31 Jul 2008 Posts: 53 Location: NY

Hi,
Did u check the timestamp ( if present in the file).
Probably it was written after the read was performed.

Cris

mainframesguru · New User Joined: 24 Jun 2005 Posts: 36 Location: Hyderabad

Hi Cristopher,

The file is opened in INPUT mode only, and the record exists
from long time, i.e not added in that batch.

I am making a wild guess, Does CPU % not available during
that read, could cause such abend?

CICS Guy · Posted: Wed Sep 24, 2008 5:57 pm

dick scherrer · Posted: Wed Sep 24, 2008 9:54 pm

Hello,

Most likely, there is a problem in the code. Some variable is not properly initialized or set to some current proper value.

Is the "not found" always the same record?

mainframesguru · New User Joined: 24 Jun 2005 Posts: 36 Location: Hyderabad

Hi Dick,

No. It is not always the same record.
And if the problem is with logic, then rerunning the same job, without any changes, would have caused the abend again...isn't it?

eHorizon.Andrew · Posted: Thu Sep 25, 2008 12:31 pm

is that file only used by your program? only reading action?...

mainframesguru · New User Joined: 24 Jun 2005 Posts: 36 Location: Hyderabad

Hi,

It is used by other programs/Jobs also.

enrico-sorichetti · Posted: Thu Sep 25, 2008 12:36 pm

when you get a no record found issue a message followed by an abend,
look at the dump for storage overlays or unfriendly patterns

dbzTHEdinosauer · Posted: Thu Sep 25, 2008 12:37 pm

mainframesguru · New User Joined: 24 Jun 2005 Posts: 36 Location: Hyderabad

Hi

Thanks for your kind advice.

As you said, logically speaking, if there is a problem with the code,
Then even if we execute the program 1000 times with same data,
the output should never vary.

But in this case, when we encounter the 'Random Read Error' and
reran the job again, it went fine. I hope you got the point.

I would check the suggestion provided by enrico sorichetti and Dick.

I would have been happy, if you had a point for resolution.

Anuj Dhawan · Posted: Thu Sep 25, 2008 1:01 pm

Hi,

Please post he SYSDUMP & SYSOUT of abended JOB if possible.

dbzTHEdinosauer · Posted: Thu Sep 25, 2008 2:31 pm

dbzTHEdinosauer · Posted: Thu Sep 25, 2008 3:34 pm

In addition, you said the code did not change from run to run.

either the code has a problem or the data was different.
I doubt if the computer burped.

Robert Sample · Posted: Thu Sep 25, 2008 5:52 pm

Suggestion: if the program does not have the VSAM extended file status codes in it, add them and recompile so the next time a 23 file status is returned you can display the extended file status data as well. That would allow the return code, function code, and feedback code which would provide additional data that just a 23.