Caché Monitoring Guide - InterSystems Documentation

5
Monitoring System Performance Using
^PERFMON
Caché provides a utility called ^PERFMON, which provides functions and a rudimentary menu to call these functions it
uses to control the MONITOR facility.
Note:
The MONITOR facility is an internal system feature that was accessible through the ^MONITOR routine in
previous versions of Caché. The ^PERFMON functions were available in previous versions in the ^VPMON
routine.
The MONITOR facility provides performance data for the Caché system by collecting counts of events at the system level
and sorting the metrics by process, routine, global, and network nodes. Since there is some overhead involved in collecting
this data, you must specifically enable the collection of counters and collect data for a specific number of processes, globals,
routines, and network nodes. Caché allocates memory at MONITOR startup to create slots for the number of processes,
routines, globals, and nodes specified. The first process to trigger an event counter allocates the first slot and continues to
add to that set of counters. Once the facility allocates all the available slots to processes, it includes any subsequent process
counts in the Other slot. It follows the same procedure for globals, routines, and nodes.
You can review reports of the data while collection is in progress. When you stop collection, memory is de-allocated and
the counter slots are gone. So, any retention of the numbers needs to be handled by writing the reports to a file (or a global).
Data is given as rates per second by default, although there is also an option for gathering the raw totals. There are also
functions which allow you to pause/resume the collection, and zero the counters.
The menu items available by running ^PERFMON correspond directly to functions available in the ^PERFMON routine,
and the input collected is used to directly supply the parameters of these functions.
Similar functions that control the same MONITOR facility are available through the classes in the %Monitor.System
package. For more information see the following chapters in this guide:
• “Using the Caché Monitor”
• “Examining Routine Performance Using ^%SYS.MONLBL”
5.1 Using ^PERFMON
You can use the ^PERFMON routine in two ways: running it interactively or calling its functions from your own routines.
The menu items available from running ^PERFMON correspond directly to callable functions in the ^PERFMON routine;
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