Controlling CICS monitoring

You can switch CICS® monitoring on or off, and select the classes of monitoring data you want to be collected, either dynamically or at CICS initialization.

About this task

When you are starting CICS, you switch the monitoring facility on by specifying the system initialization parameter MN=ON. MN=OFF is the default setting.

You can select the classes of monitoring data you want to be collected using the MNPER, MNRES, MNIDN and MNEXC system initialization parameters. You can request the collection of any combination of performance class data, transaction resource class data, and exception class data. You can change the class settings whether the CICS monitoring facility is on or off.

When CICS is running, you can control the monitoring facility dynamically. Just as at CICS initialization, you can switch monitoring on or off, and you can change the classes of monitoring data that are being collected. You can also change other settings, such as whether or not data compression is carried out for monitoring records, and the interval at which CICS produces performance class records for long-running tasks. There are two ways of controlling the monitoring facility dynamically:
  1. You can use the CICS Explorer® Regions view by selecting Operations > Regions from the CICS Explorer main menu.
  2. You can use the EXEC CICS INQUIRE MONITOR and SET MONITOR commands.
  3. You can use the CICS monitoring facility transaction CEMN.

If you activate a class of monitoring data while CICS is running, the data for that class becomes available only for transactions that are started after that point in time. You cannot add to the classes of monitoring data collected for a transaction after it has started. It is often preferable, particularly for long-running transactions, to start all classes of monitoring data at CICS initialization.

If you deactivate a class of monitoring data while CICS is running, or make other changes to the settings for the monitoring facility, this affects the monitoring data which is recorded for transactions that are running at the time you make the change. Data for these transactions might be incomplete or not recorded at all, depending on the class of monitoring data involved. The documentation for the monitoring control methods listed here explains the impact of your dynamic changes.