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 When to use DSNULI?

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George Meadows's profile image
George Meadows posted Wed December 11, 2024 12:30 PM

Hello,

We are currently looking at ways to consolidate our COBOL load modules for easier CI/CD pipeline considerations.  One of the main issues is we use multiple versions of the same program because of the various environments we use (CICS/IMS/Batch/Call Attach).  In looking at the documentation, it appears that DSNULI can do exactly what we would like.  

My question is around performance?  Has anybody converted to DSNULI, and how has the experience been?  My concern is that a performance hit of any significance could derail any attempts to adopt the standard.  

Martin Ålund's profile image
Martin Ålund

Hi George,

We are also interested in this. We have made a few tries, but not done any real evaluation.

I get a little scared when I have seen all the fixes to DSNULI during the past two years or so and that require that we re-link all load modules that use DSNULI (as we use static linking).

Will be really nice to hear from others.

Regards Martin Ålund

John Totzke's profile image
John Totzke

We use DSNULI to a limited degree to do exactly what you want. Our application team has not seen any performance issues.

It really is just another stub.

Ensure you are on the newest PTFs. At least "DSNULI  10/08/24UI98688". Our team ran into issues when they made a program change and then relinked.

The program was getting a -927 or missing CICS nodule until the latest PTFs.

Gregory DeBo's profile image
Gregory DeBo

We had a very similar situation where we had reusable services that needed to be called from different environments like IMS, CICS and TSO batch (Db2), so we would have multiple versions bound with all the different LIs, and then another fetchable would sit on top, determine the environment that you were running in, and call the appropriate fetchable for that environment.  I’m checking with the developer that championed the migration to DSNULI to see what experiences they had.  From a pure simplification standpoint, it was a clear win.

Update: I did hear back from the person that led the effort.  While the focus was on simplification, and they did not specifically performance test, they did not notice any significant difference that would raise concerns in their standard validation testing.

Jørn Thyssen's profile image
Jørn Thyssen

Hi George,

IBM Db2 Administration Tool is linked with DSNULI so we can use the same load module under TSO, CAF, and RRSAF.