Understanding PMUs

A PMU is a unit of measure that reflects the execution of a section of code. The system starts and stops a PMU at specific code locations, and the system may update a PMU anytime between the start and stop times. PeopleTools has defined a set of PMU types, and each type of PMU corresponds to the instrumentation at a specific code location, such as a SQL Execute in PSAPPSRV or a Jolt Request in the web server.

Each PMU includes:

• PMU Type.

• Instance identifier (a unique identifier for a specific PMU instance).

• Start time.

• Stop time.

• Status.

• Metrics (such as number of SQL fetches or buffer size used in a Jolt response).

See PMU Definitions.

Open PMUs are those that are currently being processed. These are PMUs for which a "stop" has not yet been received. Completed PMUs are those for which a "stop" has been received.

PMUs can assume a parent-child relationship. Child-PMUs start within a parent-PMU. Child-PMUs are linked to their parent by the parent instance ID. You can view PMUs within a tree structure that reveals the hierarchy of parent-child PMUs and indicates the processing times at each level.