The WebSphere® Real
Time perspective (WRTP) helps you trace specific WebSphere Real Time (WRT) events over time.
The perspective helps you identify unusual or exceptional events
that might occur when you run a WRT application. The trace information
can be presented in various ways, including linear or logarithmic
scales, and histograms. WRTP provides some pre-defined trace point
views that are especially helpful.
Example traces include:
- Data about class loading, which lets you identify factors that
have a significant impact on application performance.
- Java™ method execution.
Each view in WRTP represents a specific JVM or application operation.
A view includes the following information:
- The component to which the specific target operation belongs.
- An entry trace point, representing the start of a specific target
operation and a parameter within that operation.
- One or more exit trace points, representing the end of a specific
target operation and a parameter within that operation.
- One or more information trace points, enabling you to filter specific
detail from among the data collected during the trace.
The predefined trace point views are supplied as a resource bundle,
and are automatically provided within the Health Center GUI. You can
create and customize more views, and make them available to Health
Center by adding them to a custom view store.
Data about trace points is recorded to help with the analysis.
For example, each time the application reaches an entry trace point,
the operation start time is recorded. Similarly, when the corresponding
exit point is reached, the time is recorded and the total time to
perform the operation is calculated. This data is used for graphical
displays of information, and also for determinism calculations.
Within the WRTP, you can choose from predefined or customized views.
Predefined views include:
- Class loading, showing the time spent in class loading.
- Incremental garbage collection, showing the time taken by the
global garbage collection cycle.
- JIT compilation, showing the time spent in various compilation
phases.
- Synchronous garbage collection, showing the time spent in synchronous
garbage collection.
- User driven garbage collection, showing the time taken in garbage
collection cycles invoked by the application.
Customized views are described
in
Customizing the WebSphere Real Time perspective.