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Load Testing

Posted by daniel on October 30, 2003 at 7:15 AM PST

The Virginia Tech supercomputer is ramping up for its official launch after the first of the year. We imagine an effective switcher ad for a project that was originally slated to deploy on Dells and moved over to more than a thousand PowerMac G5s.

I was in the market for a new machine. I was hoping to get ten teraflops by the end of the year. I'd never used a Mac and had been looking at Dells and IBMs. Then Apple released the G5 on June 23. A week later I bought 1,100 duals online at the Apple Store. I'm Srinidhi Varadarajan and I build Supercomputers at Virginia Tech.

Of course Dr. Varadarajan didn't really say this. But in Confessions of the World's Largest Switcher we report on his presentation at O'Reilly's Mac OS X Con. The project went from an idea to funding to construction and initial tests in about six months.

In Also in Java Today we feature the latest in Jack Shirazi and Kirk Pepperdine's developerWorks series on performance tuning. In A load of stress , they explain "Stress testing is aimed at discovering under what conditions your application's performance becomes unacceptable. You do this by changing the application inputs to place a heavier and heavier load on the application, measuring how performance changes with the variation in those inputs. This activity is also called load testing, though load testing usually describes a specific type of stress testing -- increasing the number of users to stress test your application."

They explain the requirements of a stress testing tool by first presenting a naive approach and then examining further requirements such as "handling extended interactions, where one request depends on the results of the previous one? What about handling cookies? Cookies are essential for many session-oriented J2EE systems. How about varying data input? What if your J2EE application client needs to process some JavaScript in order to proceed with the next communication? After you've collected the response time data, how are you going to analyze it? What about other types of monitoring, such as CPU time, network utilization, heap size, paging activity, or database activity."

For our other featured article we point to an ONJava article on Developing with Maven . Rob Herbst explains why he thinks you will be replacing Ant as your build tool of choice with Maven. He shows you how to get going with Maven, how to customize it, and how to run your Ant tasks in Maven.

In today's featured Weblogs , Chris Adamson checks in from the Mac OS X conference with a discussion about the differences between using a GUI builder that generates code and one that generates some sort of property list that determines how the objects should be reconstituted and wired to code. In Defrosting Java GUIs, Chris discusses how this might be achieved in Java.

In Projects and Communities , join the discussion in the JavaPedia on Access modifiers . One of the first things students learn when coding in Java is the meaning of public, private, and protected, but they often do not learn when it is appropriate to use each one. Help shape the definitions above the line and provide your comments below the line. The Java Games community updates their home page with the latest in Java gaming news. Currently they are featuring stories on BT promoting online gaming and broadband and Half-Life 2 game release is uncertain.

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