Java virtual machine profiling
Starting with JVM v1.5 and WAS v6.1, the Java Virtual Machine Tool Interface (JVMTI) replaces the Java Virtual Machine Profiling Interface (JVMPI).
The JVMTI is a native programming interface that provides tools the ability to inspect the state of the JVM.
Both interfaces provide the ability to collect information about the JVM that runs the appserver. The Tivoli Performance Viewer leverages these interfaces to enable more comprehensive performance analysis.
JVMTI is a two-way function call interface between the JVM and an in-process profiler agent. The JVM notifies the profiler agent of various events, for example, garbage collection and thread starts. The profiler agent activates or deactivates specific event notifications that are based on the needs of the profiler. The allocate, move, and free object counters that are provided through the JVMPI interface are not available through the JVMTI implementation in WAS V6.1.
JVMTI supports partial profiling, by enabling you to choose which types of profiling information to collect and to select certain subsets of the time during which the JVM API is active. JVMTI moderately increases the performance impact. Therefore, it is recommended that you use JVMTI monitoring to help diagnose application problems only.
Related tasks
Enabling the Java virtual machine profiler data