Adding thread history data sets

This topic discusses thread history datasets in OMEGAMON for Db2 on z/OS Performance Expert (OMPE) and explains how you can increase the number of datasets. The key is that you must restart the OMPE collector in order for new datasets to be recognized.

When you run OMPE with system substitution variables, a KCIPARSE step will run the next time OMPE starts. If you make changes to the permanent RKD2PAR file, the changes are not picked up until the next time KCIPARSE is run, which will happen when you start the OMPE collector.

The KCIPARSE step creates temporary files that are copies of the runtime files, but with substitutions made. The RKD2PAR file located where the COPT members are is copied to a temporary dataset. OMPE then runs from that temporary file; for example:

//KAND2PU DD DISP=SHR, 
//DSN=&USERD2PU 
//TMPD2PU DD DISP=(,PASS),DSN=&&TMPD2PU,DSNTYPE=(LIBRARY,1), 
//UNIT=SYSDA,SPACE=(CYL,(5,5,440)), 
//DCB=(RECFM=FB,LRECL=80,BLKSIZE=8880)

These startup messages show the RKD2PAR file as a temporary file:

KO2Z056I OM02 V540 01-RKANPAR VOL=WKP100 DSN=SYS18283.T192035.RA000.OMPEPK3S.TMPPARU.H04
KO2Z056I OM02 V540 02-RKANPAR VOL=WKP104 DSN=SYS18283.T192035.RA000.OMPEPK3S.TMPD2PU.H04

If you change the permanent RKD2PAR file, the change is not recognized until the next time KCIPARSE is run, when OMPE starts.

The only way to avoid this behavior is not to perform system variable substitution for the RKD2PAR dataset. In the OMPE Startup JCL, the following DSN names would have to be changed to the original names (not the temporary names):

//RKANPAR DD DISP=(OLD,PASS),
//DSN=*.KCIPARSE.TMPPARU
//DD DISP=(OLD,PASS), 
//DSN=*.KCIPARSE.TMPD2PU