MACROMEDIA COLDFUSION MX-CLUSTERCATS Use Manual page 31

hitting your web server. By using the software in conjunction with your defined
benchmarks and formal test plans, you can confidently determine whether your web
application is ready for deployment.
Another reason to load test is to verify your failover capabilities. Failover ensures that if a
primary server within a cluster of servers stops functioning, subsequent user requests are
directed to another server within the cluster. Failover is addressed in more depth in
"What is website availability?" on page 23. Using load-testing software, you can
essentially force a server redirection by designating a computer as "unavailable" or by
shutting it down.
Note: ClusterCATS uses the HTTP protocol to redirect packets of data from a failed server
to an available server. Therefore, it is important to verify that your load-testing tool can
handle HTTP redirections properly before you initiate load testing.
How to load test your web applications
Before you can load test, you must purchase a load-testing software tool and learn how to
use it.
There is a variety of good load-testing software tools on the market, including Segue's
SilkPerformer, Mercury Interactive's LoadRunner, and RSW's e-LOAD. Each of these
packages provides substantial Web-enabled software-testing solutions that help you
effectively simulate and test load.
After you purchase, install, and learn to use load-testing software, you determine
benchmarks that you want to—or must—achieve for your website, to ensure a good user
experience. Following that, you formalize your testing strategy by designing and
developing written test plans against which you execute your tests.
When the test plans are written and approved, you run the tests. After you do so, you
capture and analyze the load-testing results and report the statistics to the development
team. From there, you'll need to reach consensus about the most serious problems you
discovered, the necessary changes to make, and the best way to implement the fixes. After
the changes are made and a new build of the application is available, you rerun the tests
to look for performance improvements. Again, you analyze the testing results, and
continue this cycle until the site is operating within the established parameters that you've
set. When your team agrees that the site scales well and is operating at peak performance
under heavy stress, you're ready to deploy the application into a production environment.
Successful scalability implementations 21