Hah, I’ll bet you thought this blog was dead … didn’t you?

It’s not … at least mostly not dead.

Here’s a hint that might save your bacon sometime in the future.

It may seem obvious to some people … but Service Programs are probably the BEST enhancement to System i that IBM ever implemented.

I’m in the process of completely revamping some code where I am completely replacing the guts of a bunch of routines. These routines are invoked from ALL OVER the application.

Because the routines are embedded in a service program, I don’t have to TOUCH the core application logic. I don’t even have to recompile it. As long as the prototype of the service program doesn’t change, the application will pick up the service program changes without a hitch.

Obviously you have to take care not to change the SIGNATURE of the service program … but if you’re just changing the logic and not the parameters or procedure names, you should be good.

The effort to build the service program might not seem worth it now … but next year, when you have to rework the logic, you will be thankful you put in the extra work.

[tags]System i, iSeries, RPG, Service Programs[/tags]

About David:
David is a Principal Software Engineer for PTC, Integrity Business Unit. He cut his teeth on the S/36 and has more than 25 years of experience on the IBM i / System i / iSeries / AS400. He primarily works in Java and ILE RPG specializing in cross platform integrations. David has received the COMMON Distinguished Service award and was named an IBM Power Systems Champion. David is an active volunteer with the American Diabetes Association's Tour de Cure fundraising bike ride. He is currently captain of Team RED Chicago. David runs and maintains midrange.com. His personal blog is Geeky Ramblings.