Dictionary records for CMF Performance Class data

A dictionary record holds definitional information about each data field in a performance class data record. It contains information for predefined CICSĀ® fields, and from any user fields in the Monitoring Control Table (MCT) specified for the CICS run.

When CICS monitoring is switched on, and you activate the monitoring performance class (MNPER=ON), CICS first writes a performance class dictionary record to the current SMF data set, and then begins to write the monitoring performance class data records. A new dictionary record, which always precedes the monitoring performance class data it relates to, is written whenever the user:
  • Starts CICS with the performance class active, and CICS monitoring on.
  • Changes the status of the monitoring performance class from inactive to active, with CICS monitoring on. If monitoring is off and the monitoring performance class is switched from inactive to active, a dictionary record is scheduled to be written the next time monitoring is activated.

However, if SMF switches data sets during the period when CICS monitoring is writing performance class data, CICS does not write a new dictionary record, and therefore a CICS performance dictionary record is not the first monitoring performance record on the new SMF data set.