Summary

Load testing is an important but often overlooked activity of the system administrator. It can help you to make initial architectural decisions as well as to validate the decisions you’ve previously made. In this chapter, you examined the following topics:

• Scalability, the ability of a system to handle increased load without experiencing performance problems or reliability issues, is driven by many factors. In a Tomcat installation, some of those factors are server hardware, software configuration, and deployment architecture.

• JMeter is an open-source load tester, which is part of the Jakarta project. I covered JMeter load testing techniques from the simple to the advanced.

• Server load testing and application load testing require different approaches. They’re tightly coupled, and it’s up to the server administrator to gauge how application code affects server performance and to understand which factors contribute to performance issues.

The open-source world also has more to offer in terms of load testing tools. For example, the Grinder (http://grinder.sourceforge.net) is a well-established Java tool. A great resource for finding the latest in open-source load testing tools is the FreshMeat.net open-source software archive site, which includes a category specifically for these kinds of tools at http://freshmeat.net/browse/863/.

Additionally, many testing resources are available on the Web. A great place to look for a list of sites is the Open Directory Software Testing list (http://www.dmoz.org/Computers/Programming/Software_Testing/), which is a directory of sites that focus on testing topics.