Performance Monitor Meta-Data Definitions
The Performance Monitor uses the following meta-data definitions:
Performance Monitor agents send PMUs and events to the monitor. Each PMU and event contains one or more metrics. Each metric has a unique identifier. Metric definitions are the building blocks for creating PMUs and events. PMUs and events comprise up to six numeric values and one string metric value. One metric definition can appear in multiple event and PMU definitions.
Events are notifications containing performance metrics that are different from PMUs in that they are not hierarchical, and they do not have durations. PeopleTools has defined a set of event types, and each type of event is reported at a specific location in the instrumented code.
Each event has:
Instance identifier (a unique identifier for a specific event instance).
Metrics (such as CPU usage and memory allocation).
Event definitions group as many as seven metrics to measure the intended performance data. Some events do not have metrics.
A context definition applies only to PMU definitions. Contexts provide additional information so that PMU performance data can be displayed and searched more effectively. For example, a context definition enables you to group and sort numeric values, such as an execute count, by page name. Contexts enable the system to assign the data to various elements such as pages, components, service calls, and so on. Without contexts, you have only numeric data in no understandable grouping.
PMU metrics contain data that is specific to that PMU. Context values, on the other hand, are common to the entire user request or a specific tier. The system uses contexts to "flatten" a PMU tree. For example, you do not have to navigate up from a SQL PMU to an ICPanel PMU to see what component generated that SQL statement.
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:
Instance identifier (a unique identifier for a specific PMU instance).
Metrics (such as number of SQL fetches or buffer size that is used in a Jolt response).
A PMU represents a section of code that is bracketed by calls to an internal instrumentation API that signal the start and stop of that logical unit of code.
PMU definitions group as many as seven metrics to measure the intended performance data. Some PMUs do not have metrics.