WAS v8.5 > Monitoring > Monitoring overall system health > PMI
PMI architecture
The PMI uses a client-server architecture.
The server collects performance data from various WebSphere Application Server components. A client retrieves performance data from one or more servers and processes the data. WAS, v6 supports the Java EE Management Reference Implementation (JSR-77).
In WAS, v6 and later, PMI counters are enabled, based on a monitoring or instrumentation level. The levels are None, Basic, Extended, All, and Custom. These levels are specified in the PMI module XML file. Enabling the module at a given level includes all the counters at the given level plus counters from levels following the given level. So, enabling the module at the extended level enables all the counters at that level plus all the basic level counters as well.
JSR-077 defines a set of statistics for Java EE components as part of the StatisticProvider interface. The PMI monitoring level of Basic includes all of the JSR-077 specified statistics. PMI is set to monitor at a Basic level by default.
As shown in the following figure, the server collects PMI data in memory. This data consists of counters such as servlet response time and data connection pool usage. The data points are then retrieved using a web client, a Java client, or a JMX client. WAS contains Tivoli Performance Viewer, a Java client which displays and monitors performance data. See the Monitoring performance with Tivoli Performance Viewer, Third-party performance monitoring and management solutions, and Develop custom PMI monitoring applications topics for more information on monitoring tools.
The figure shows
the overall PMI architecture. On the right side, the server updates
and keeps PMI data in memory. The left side displays a web client, a Java client, and a JMX client retrieving the performance data.
Related concepts:
Custom PMI API
Related
Enable PMI data page
Monitoring performance with Tivoli Performance Viewer
Develop custom PMI monitoring applications
Reference:
Third-party performance monitoring and management solutions