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Relation Between z/OS and CICS.

PostPosted: Sun Sep 23, 2012 10:48 am
by Mehdi shri
Hi friends.
In our site there are 3 CICS works on an z/OS.
I want to know where I can find out and see the relationship between a CICS and z/OS from TSO console.
In other words, when I copy new version of a load in a typical PDS liberary and CEMT SET PROG(PROGNAME) it in CICS terminal, how CICS understands must do newing this typical load(PROGNAME) from which liberary? Because there are many PDS liberary contained load modules in our z/OS environment.
Special Thanks.

Re: Relation Between z/OS and CICS.

PostPosted: Sun Sep 23, 2012 12:13 pm
by Robert Sample
Each CICS region running under z/OS has JCL that is executed. Some of the JCL is the same for every CICS region, but some of the JCL is unique to each region.

Within the job, there will be a DD name DFHRPL; this DD name usually consists of a series of concatenated load libraries. Every program running under CICS must be located in one of these load libraries. When a newcopy is done in the CICS region, CICS goes through the concatenated data sets and loads the first copy of the program that it finds. The program could exist in 2 ... 5 ... 25 different libraries in that concatenation list, but the load is done from the first library found to contain the load module (program).

Note: if a load library is not found in the DFHRPL concatenation, then no program in that load libary can be loaded via newcopy into CICS -- period. There may be programs with the same names in the DFHRPL concatenation, but they are different programs since they are in different load libraries.