HPjmeter 4.3 User's Guide

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.

Figure 42 Monitoring Metric: Allocated Object Statistics by Class

Related Topics

• Identifying Excessive Object Allocation (page 54)

• JVM Agent Options (page 27)

• “Data Sampling Considerations” (page 213)

• Mark an Item for Search (page 203)

• Find a Search Pattern (page 204)

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