Monday, October 09, 2006

Review topics: Change Control

I am starting to summarize a few mainframe review questions that could come up in phone interviews or in technical quizzes given by recruiters. This is all part of a review process that may lead to my own recertification in a job search.

Topic: Change Control

The skill most often requested is Endeavor. I am familiar with ChangeMan and CA-Librarian.

I became familiar with ChangeMan in the mid 1990s at ReliaStar. The package automatically stages components of an elevation (source, link decks, parmlibs, procs, JCL, etc) into various stages of Test, QA, and production. The package will not let you compile and link without linking the source. This automatically guarantees that when a package is moved to production, the source matches the load modules (a security issue). That to me sounds like a good concept for an interview question.

I first had CA-Librarian in 1990. At the time, one had to "process" a module to freeze, and it was possible to produce load modules that could be elevated without freezing the source. On the other hand, a source module itself could not be elevated without being frozen individually. This does sound like it could expose an installation to security problems, and I don't know whether this has been changed since then. I suspect that it has.

More review topics will follow.

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