Product ReviewJava Performance Gets a BoostOptimize It! 4.0

• By Lea Walker
• January 17, 2001

All software developers want to achieve optimum application performance. Java developers in particular need to wring the last drop of performance from their applications. But to tune up an app, you have to know a few things, such as where it's spending most of its compute cycles and how efficiently it uses system resources. You have to be able to pinpoint and eliminate bottlenecks, plug memory leaks, ferret out inefficient algorithms, and unearth inefficient processor usage.

Shipped in September 2000, Optimize It! 4.0 from Intuitive Systems is a Java-code profiling tool designed to do all of the above. According to the vendor, it helps Java developers improve the performance of servlets, JavaBeans, Java Server Pages, and complex server-based Java applications. This latest version has lots of new features, including universal JVM support, offline profiling for testing programs in production environments, and the ability to integrate with a wide range of application servers.

In December, Java Report's writers chose Optimize It! to receive a Writers' Choice Award as the year's top testing tool. This one was a big vote-getter (no hand recount requests, please!), and so we asked San Francisco-based software developer Lea Walker to download the trial version and find out what made it so popular.

—John K. Waters
Product Review Editor

	Version Reviewed: 4.0 Current Version: 4.0
	CUP RATING SYSTEM: 5 Outstanding 4 Very Good 3 Acceptable 2 Has Potential 1 Poor

INTUITIVE SYSTEMS DESCRIBES Optimize It! 4.0 as a comprehensive language-profiling tool for Java that enables developers to improve the performance of Java programs, including servlets, EJBs, and JSPs. A modest claim, and one that was borne out by my experience with the product. I found Optimize It! to be a comprehensive suite of tools that made it surprisingly easy to quickly locate code inefficiencies and memory leaks. And with full support for Sun's JDK 1.1, and versions 1.2 and 1.3 for J2SE, it offers users a real range of choices for profiling and optimizing Java code.

Written in Java, Optimize It! lets users track the CPU and memory usage of any Java component, whether or not source code is available. There's full support for viewing Java threads and the details of Java's garbage-collection mechanism. A variety of graphs and reports, including HTML, are available to show users exactly what's happening in their Java code.

I downloaded the trial version of the product, which anyone can try for 15 days, and installed it on a Windows NT workstation. I had no problems with the installation—in fact, it was a breeze. The configuration process was simple and straightforward, guided by a set of comprehensive wizards. You do have to configure a default JVM during the install, but you can change it anytime afterward. Optimize It! stores the locations of all JVMs discovered, so switching between them is simple.

To put the product through its paces, I profiled a Java 2-based applet and a servlet based on the Java SDK 2.0, both of which I wrote with lots of lousy code: temporary objects, methods used as the terminating state for control blocks, the String class overused when StringBuffer would have been more efficient.

Profiling applets and servlets proved to be an easy task in Optimize It!. Once the JVM was configured, I selected "Applet" from the startup tab in the settings dialog box, and then entered the path to the HTML containing my applet in the "Applet HTML or URL" field. Then I simply hit the "Start Now" button.

Profiling servlets, JSPs, and remote applications—in my experience, a frustrating and often fruitless exercise—wasn't much more complicated, and the process yielded a wealth of useful information. I simply entered the path to the servlet class, and a browser popped up and executed the servlet while Optimize It! displayed its profiling results.

Optimize It!'s memory profiler counts the number of instances allocated by class, and lets users see which method instantiated which instance. I used it quite effectively to track down the many temporary object allocations I had coded into my applet and servlet. The memory profiler can also help to ensure that all instances of objects are garbage collected, removing any memory leaks in the code.

Optimize It!'s CPU profiler shows users which methods are "sucking" computing cycles. This is where the rubber really hits the road, as far as application performance is concerned. Identify which methods require the most CPU cycles, and you've got a place to start looking for performance problems in the code. The CPU profiler can be set up to start automatically, but Optimize It! doesn't offer suggestions on what may be causing the performance problems. Still, it gives users an X-marks-the-spot heads up so they know where to start digging. During my test, the CPU profiler pointed out the piggiest methods in both applets and servlets, allowing me to spend my optimization efforts, well, optimally.

Optimize It! provides useful views of the resources being used by a profiled application. You can view information about the VM that's running, including details about the heap, number of threads, loaded classes, and garbage collection. This feature is quite useful for defining an application's minimum system requirements before distribution. Also, I was able to select a method I noticed was gobbling CPU cycles, click on the "View Source" button, and have the CPU profiler display the source of the method.

Once I found the performance problems in my test applet and servlet, replacing the clunky code was a simple matter. With the changes in place, I used Optimize It! to reprofile the software, which showed much improvement.

Among the new features in the 4.0 version, I particularly liked the product's offline profiling capability. As the vendor says, it provides users with the ability to record performance data with such limited overhead that it becomes possible to monitor the performance of applications in production. This feature allows you to save performance data and load it into Optimize It! later for analysis or comparison.

The product's ability to detect performance problems in application server environments is another new feature. Although I didn't have a chance to do much with it, I suspect it will prove to be an important capability for many developers. The product integrates with a bunch of app servers and servlet engines, including:

• Allaire JRun
• Apache JServ and Tomcat
• Apple WebObjects
• ATG Dynamo
• BEA WebLogic
• IBM WebSphere
• iPlanet Web Server Enterprise Edition
• Sun ServletRunner and JavaWeb-Server
• Unify eWave ServletExec

Optimize It! provides detailed help on configuration for several application servers and servlet engines. It provides detailed instructions for integrating some other products not directly supported.

And the universal Java VM support is great. It enables developers to profile their Java applications running on any Sun-standards-compliant JVM.

Most features of Optimize It! are available for all versions of Java, but some—e.g., filtering to remove fast methods and display of invocation counts—are available only for Java 2. Filters for both memory and CPU profiling (see Figure 1), saving snapshots of profiling sessions, and integration with application servers and IDEs are available for all versions.

Figure 1. Optimize It! memory profiler.

I found Optimize It! to be a great tool, easily a "must try" for any developer looking to reduce cycle times and improve the overall performance of his/her Java applications. At the end of the day, it's all about making your Java code run faster and more efficiently. This product really does make it easy to spot the code responsible for excessive memory allocations and inefficient CPU usage. I'm not sure what more I would want from a performance profiler.

Editor's Note
Readers have told us that testing has become a real priority in most software development organizations. Yet debugging and troubleshooting by its very nature can be tedious and time consuming. It can be an especially irksome task when everyone in the company is howling about reducing time-to-market out of one side of their mouths, while yodeling about maintaining high-performance standards out of the other side.

If there are other testing and performance profiling tools you'd like us to review, let us know. Send e-mail to Product Review Editor John K. Waters at [email protected].