Chapter 15. Profiling Java Applications

• Supported Platforms

• Downloading and Installing the NetBeans Profiler

• Profiling Primer

• Starting a Profiling Session

• The Profiler Control Panel

• Monitoring an Application

• Surviving Generations and Memory Leaks

• Analyzing Performance

• Analyzing Code Fragment Performance

• Analyzing Memory Usage

• Attaching the Profiler to a JVM

CREATING A ROBUST JAVA APPLICATION that is ready for production requires an implementation that will scale up as the load increases. In other words, your application should continue to perform well as users are added or additional data are processed, etc. Your application will not scale if it over con sumes resources such as memory and CPU time. A profiler is a tool that helps you detect whether your application is suffering from performance problems because it is consuming more resources than it should. Assumptions about Java application performance are frequently wrong, so it is important to use a profiling tool to help find and eliminate problems.

The NetBeans Profiler is a powerful tool that can help you identify performance problems in your application. Since it is integrated into the IDE, profiling becomes a simple task that does not require additional tools. The NetBeans Profiler allows you to monitor your application, determine the time used by specific methods, and examine how your application uses memory. The NetBeans Profiler uses advanced technology that reduces profiling overhead, making it easier for you to learn about the performance of your application. Following are some of the features of the NetBeans Profiler:

• Low Overhead Profiling. You control the profiler's performance impact on your application. Based on your selections, the performance impact will range from extensive to none.

• CPU Performance Profiling. Time spent in every method of your application or just in selected methods can be reported.

• Memory Profiling. You can check for excessive object allocations.

• Memory Leak Detection. The profiler's statistical reports make it easy to detect object instances that are leaking.