A Debugging/Profiling Tool by ej-technologies GmbH

Memory profiling
JProfiler's memory view section offers dynamically updated views on memory usage and views that show information about allocations spots. All views have several aggregation levels and can show live and garbage collected objects.

All objects - Shows classes or packages of all objects on the heap with instance counts and size information. You can mark current values and show differences.

Recorded objects - Shows classes or packages of all recorded objects. You can mark current values and show differences.

Allocation call tree - Shows a call tree or methods, classes, packages or J2EE components with annotated allocations of selected classes.

Allocation hot spots - Shows a list of methods, classes, packages or J2EE components that allocate selected classes. You can mark current values and show differences. The tree of backtraces can be shown for each hot spot.

Heap walker
In JProfiler's heap walker you can take a snapshot of the heap and drill down to objects of interest by performing selection steps. The heap walker has five views:

Classes - Shows all classes and their instances.

Allocations - Shows allocation tree and allocation hot spots for recorded objects.

References - Shows a graph of references for individual objects and offers a "show path to garbage collector root" functionality. Also offers cumulated views for incoming and outgoing references.

Data - Shows instance and class data for individual objects.

Time - Shows a time-resolved histogram of recorded objects.

CPU profiling
JProfiler offers various ways to record the call tree to optimize for performance or detail. The thread or thread group as well as the thread status can be chosen for all views. All views can be aggregated on a method, class, package or J2EE component level. The CPU view section contains:

Call tree - Shows a cumulated top-down tree of all recorded call sequences in the JVM. JDBC, JMS and JNDI service calls are annotated into the call tree. The call tree can be split for different request URL to a servlet or JSP.

Hot spots - Shows the list of the most time consuming methods. The tree of backtraces can be shown for each hot spot. Hotspots can be calculated for method calls, JDBC, JMS and JNDI service calls, as well as for URL invocations.

Call graph - Shows a graph of call sequences starting from selected methods, classes, packages or J2EE components.

Thread profiling
For thread profiling, JProfiler offers the following views:

Thread history - Shows a timeline with thread activity and thread status.

Thread monitor - Shows a list of all live threads with their current activity.

Deadlock detection graph - Shows a graph of all deadlocks in the JVM.

Current monitor usage - Shows the currently used monitors and their associated threads.

Monitor usage history - Shows the history of significant waiting and blocking events.

Monitor usage statistics - Shows statistics for monitors grouped by monitors, threads and classes of monitors.

VM telemetry
To observe the internal state of your JVM, JProfiler offers various telemetry views:

Heap - Shows a timeline with a graph of the used heap and the heap size.

Objects - Shows a timeline with a graph of live objects and arrays.

Garbage collector - Shows a timeline with a graph of garbage collector activity.

Classes - Shows a timeline with a graph of loaded classes.

Threads - Shows a timeline with a graph of active threads.