HPjmeter 4.2 User's Guide

Figure 8-8 Monitoring Metric: Allocated Object Statistics by Class
Related Topics
• Identifying Excessive Object Allocation (page 44)
• JVM Agent Options (page 17)
• “Data Sampling Considerations”
• Mark an Item for Search (page 178)
• Find a Search Pattern (page 179)
Allocating Method Statistics
Shows the methods that allocate the most objects.
This metric is useful when you choose to decrease heap pressure by modifying the application
code.
Guidelines
Methods listed at the top should become the primary candidates for optimization.
Details
For those classes that are instrumented (visible through the JVM agent verbose flag), every object
allocation in every method is instrumented to report allocations. However, sampling is used to
minimize overhead, so the metric reports allocation percentages, not total allocation counts.
These percentages are not absolute across the entire application, but are computed with respect
to allocations in instrumented classes.
Sampling minimizes overhead and focuses attention on user code. To discover allocation statistics
about application server classes, use the include and exclude filtering flags in the JVM agent
options.
The reported data is cumulative over the lifetime of the session, and accuracy will improve as
the session length increases.
128 Using Visualizer Functions