Use Java virtual machine profiling to gather data about your system for performance analysis.
The Java virtual machine Tool Interface (JVMTI) is a native programming interface that provides tools the ability to inspect the state of the JVM. This interface is new for the JVM, V1.5. JVMTI replaces the Java virtual machine Profiling Interface (JVMPI), which is supported in WebSphere Application Server, V6.0.2 and earlier. The JVMPI interface is deprecated as of WebSphere Application Server V6.1.
Both interfaces (JVMTI and JVMPI) provide the ability to collect information about the JVM that runs the application server. 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 WebSphere Application Server 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 greatly increases the performance impact. Therefore, IBM recommends
that you use JVMTI monitoring to help diagnose application problems only.