Enabling PMI data collection
Enable PMI data collection to diagnose problems and tune application performance.
Before you begin
About this task
When PMI service is enabled, the monitoring of individual components can be enabled or disabled dynamically. PMI provides four predefined statistic sets that can be used to enable a set of statistics. The following table provides details about the statistic sets. If the predefined statistic sets does not meet your monitoring requirement, the Custom option can be used to selectively enable or disable individual statistics.
Statistic set | Description |
---|---|
None | All statistics are disabled. |
Basic | Statistics specified in J2EE 1.4, as well as popular statistics like CPU usage and live HTTP sessions are enabled. This set is enabled out-of-the-box and provides basic performance data about runtime and application components. |
Extended | Basic set plus key statistics from various WebSphere® Application Server components like WLM, and dynamic caching are enabled. This set provides detailed performance data about various runtime and application components. |
All | All statistics are enabled. |
Custom | Enable or disable statistics selectively. |
Custom setting
WebSphere Application Server Version 6.0 introduces fine-grained control to enable/disable statistics individually. The fine-grained control is available under the custom statistic set.
Sequential Update
In order to minimize the monitoring overhead, the updates to CountStatistic, AverageStatistic, and TimeStatistic are not synchronized. Since these statistic types track total and average, the extra accuracy is generally not worth the performance cost. The RangeStatistic and BoundedRangeStatistic are very sensitive; therefore, they are always are synchronized. If needed, updates to all the statistic types can be synchronized by checking the Use sequential update check box.
Locking locations | Module | Module counters locked |
---|---|---|
Nodeagent, server or on-demand router | xdProcessModule | All |
Nodeagent, server or on-demand router | jvmRuntimeModule | All |
Nodeagent, server or on-demand router | systemModule | All |
Nodeagent, server or on-demand router | threadPoolModule | 6, 7, 8 |
Nodeagent, server or on-demand router | xdHeapModule | All |
Nodeagent, server or on-demand router | odrStatModule | All |
Nodeagent | xdSystemModule | All |
Server or on-demand router | DeploymentTargets | All |
Server or on-demand router | xdOdrSessionModule | All |
Server or on-demand router | servletSessionsModule | 6, 7 |
Server or on-demand router | beanModule | 11, 12 |
Server or on-demand router | webAppModule | 11, 13 |