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SIT changes not used during COLD or INTIAL startup of CICS

Question & Answer


Question

Why would CICS use system initialization table (SIT) values from the catalog during a COLD or INITIAL startup? I changed the following parameters in my active DFHSIT and reassembled the new SIT with suffix XX, but the old values are still being used by CICS.

STATRCD=ON from OFF
STATINT=010000 from 030000

When the CICS region starts up, I see that the recently assembled DFHSITXX is being used:

DFHPA1101 DFHSITXX IS BEING LOADED.
DFHPA1108 DFHSITXX HAS BEEN LOADED. (GENERATED AT: MM/DD= 01/01 HH:MM= 11:11).

My expectation for a COLD or INITIAL startup was for the values coded within the new DFHSITXX to be picked up as:

STATRCD=ON
STATINT=010000

I was surprised when I discovered the values picked up were the old values before any change:

STATRCD=OFF
STATINT=030000

I suspect these old values are being picked up from the catalog, but did not expect this behavior on a COLD or INITIAL startup.

Answer

There is an hierarchy as to what will be used by CICS. Here are the rules of guidance:

  1. JCL/SYSIN takes precedence over everything.

  2. If no JCL/SYSIN then the entries on the Catalog will take precedence if the startup is WARM or EMERGENCY.

  3. If no JCL/SYSIN and not WARM or EMERGENCY restart then the Assembled SIT being used will be used to set the values.

Although this customer was following the above rules and expectation was for the Assembled SIT to be used, it was discovered a PLT program was running at startup and setting the old values programmatically. In this case, removal of either the PLT program altogether or just the offending EXEC CICS SET STATISTICS OFF ENDOFDAY(011500) INTERVAL(030000) command resolved the problem.

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Product Synonym

CICS/TS CICSTS CICS TS CICS Transaction Server

Document Information

Modified date:
12 June 2017

UID

dwa1380733