Statistics intervals can occur simultaneously across many CICS® regions in the same MVS™ image, and this can degrade performance. To prevent this, you should vary the statistics interval occurrence time for each CICS region. You can use the sample utility program, DFH$STED, to vary automatically the end-of-day time of each CICS region it is installed in, and therefore vary the interval occurrence time of these CICS regions.
The source code for DFH$STED is supplied in the hlq.SDFHSAMP samples library, and the pregenerated version is supplied in hlq.SDFHLOAD. It uses standard EXEC CICS calls to set the times and frequencies to produce SMF statistics. The program source contains extensive comments that explain how the program functions, and also includes the documented variables. You can use the sample program asis from SDFHLOAD, or:
You should run the DFH$STED program in the third phase of CICS initialization (that is, during the second phase of PLT processing).
You can use the following three parameters to control how the end-of-day time is amended. These parameters are part of the source of DFH$STED. To change them you will have to modify the source of DFH$STED, which is located in SDFHSAMP.
This enables you to stagger the end-of-day time of each of your CICS regions by a pseudo-random amount (based upon the time of day at which the program is executing), up to a user-specified maximum value. Since intervals are calculated using the end-of-day as a base time, the occurrence of intervals are staggered by this pseudo-random drift time. The default is ten minutes.
You should set this field to CURRENT if you need the current end-of-day time, or FIXED if you need a new end-of-day time. If you specify FIXED, you should specify the new time on the EODFIXED parameter. The default value of the EODTIME parameter is FIXED.