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How to know the Application size in CICS region

PostPosted: Thu Mar 04, 2010 8:27 pm
by adurthisridhar
Hi,

I am working in a production environment and having aroundd 30 CICS regions including the production, test,quality and system test regions. Each region has different number of applications. I am working on the cost saving initiatives and trying to find the each appllication consumming how much memory in the region. Could any one please suggest me how to get the application storage details?

Thanks in anticipation.

Re: How to know the Application size in CICS region

PostPosted: Thu Mar 04, 2010 8:56 pm
by Robert Sample
1. Talk to the application people and identify each program belonging to the application.
2. For each program, look at the size of the program when loaded into CICS.
3. Add all the numbers up.

You realize, I hope, that this is essentially a useless process. It is rare for all programs of an application to be loaded into a CICS region since some of the programs are for specialized functions and may be invoked only a few times a year -- so they won't be loaded into memory most of the time. Furthermore, unless you are having short-on-storage issues in a CICS region, why does anyone care how much memory the programs are taking? CICS is very, very, very good at memory management.

Furthermore, unless you distinguish between the programs running below the line from those running above the line, you are comparing apples to pomegranates. Memory below the line is quite restricted whereas a CICS region can have literally gigabytes of memory above the line -- so there's almost no chance your applications can fill the memory above the line, anyway.

I've never heard anyone being concerned about total memory used by an application. But then, I've only been dealing with CICS for 30 years so far so there is much I have yet to learn.

Re: How to know the Application size in CICS region

PostPosted: Thu Mar 04, 2010 11:00 pm
by adurthisridhar
Thank you so much for the swift responce. But could you answer one query. If the application is in INACTIVE state (We made it inactive becuase no one is using those applications since 4 months) will it occupy any memory in the CICS (Even 1%)? If not then you are absosultely correct. This is useless to get the memory usage of each application in CICS region.

If yes then we are having lot of applications in the production regions which are in INACTIVE state. So I would like to decommission the INACTIVE applications in the region, which may reduce atleast 1% memory usage.

This is just my idea. I am not sure. I might me wrong.

Re: How to know the Application size in CICS region

PostPosted: Thu Mar 04, 2010 11:30 pm
by Robert Sample
When you sign onto a CICS region and type in a transaction name, CICS looks up the associated program for the transaction. It then looks to see if the program is in memory; if not, it loads the program from DFHRPL. So if a program is only used by one transaction and that transaction is not active, then the program memory usage in CICS is zero bytes. If you are not doing so, you can set up the STAT transaction to execute at CICS shutdown and review the program usage statistics for the region. If none of the programs in the application are listed as active, then none of the application programs are using CICS memory.

CICS doesn't really work in terms of applications -- it works with transactions, programs, TD queues, TS queues, files, and so forth. Even if there are no applications running in the CICS region, there is some memory used by system tables, CICS itself, system programs (such as the signon program or CEDA or CEDF), buffers for files that are opened when the region comes up, and so forth.

Re: How to know the Application size in CICS region

PostPosted: Fri Mar 05, 2010 1:05 am
by dick scherrer
Hello,

I am working on the cost saving initiatives and trying to find the each appllication consumming how much memory in the region
How might knowing program/application size contribute to "cost saving"?

I believe doing some research on how much i/o (database, vsam, etc) and how many cpu cycles are used will give more useful info than knowing the "size" of the executables. Also, in many cics systems, a handful of programs/transactions account for most of the usage. This handful may have hundreds or thousands of concurrent users.

Re: How to know the Application size in CICS region

PostPosted: Fri Mar 05, 2010 11:36 am
by adurthisridhar
Thank you so much for the responses. I understood some concepts due to this conversations. Thanks to IBM mainframe forums

Thanks,
Sridhar A

Re: How to know the Application size in CICS region

PostPosted: Sat Mar 06, 2010 12:41 am
by dick scherrer
You're welcome - good luck :)

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