Refresh processing for the Usage Monitor

The Usage Monitor includes commands that you can issue dynamically to alter processing but that are active only for the duration of the current Usage Monitor session. To implement a change to both the running Usage Monitor and to the initialization commands for starting subsequent Usage Monitor sessions, you can use the refresh facility.

Refresh processing involves the execution of the command stream placed in the HZAZIN file, without the requirement of stopping and restarting the Usage Monitor. As a result, refresh processing can verify the validity of the initialization command stream so that changes are made and tested dynamically. This ensures that future Usage Monitor sessions do not encounter initialization command stream errors.

Some commands set a switch for logic control, or set a numeric value to be used during processing. These commands specify the values to be used in the future. Other commands pertaining to inclusion and exclusion masking add a mask to, or remove a mask from, the active mask list, so are part of an accumulation of commands which specify future processing.

Consider the example where several exclusion masks are active, and a change to deactivate one of the masks is required. A command to deactivate the mask might be issued dynamically, but if this change is to be made permanent, then the HZAZIN file needs to be updated. The alternative is to remove the command setting the exclusion from the HZAZIN file, and to then issue the Usage Monitor REF command to initiate a refresh.

Before the first HZAZIN command is run during refresh processing, the program mask exclusion list is set to the default list. Further, all data set name exclusion masks are deactivated, and all data set name inclusion masks are deactivated. This order of deactivation ensures that there is no loss of data that would otherwise be collected. However, there is the possibility that data which would have been excluded is collected during the short window between the reset of the mask lists and the processing of the HZAZIN commands.

The response to each command in the HZAZIN file is written to the HZAZMSG file. A summary WTO message, indicating whether any errors are found or not, is issued after refresh processing has finished.

Stopping the Usage Monitor and restarting it, produces the same active exclusion masks as a refresh. It also produces a data collection outage. For more information, see the REF command in the next topic for a list of the processes performed during a refresh operation.