Balancing the Web Server Load

Hardware- and software-based systems compete on much more than raw performance numbers.

Server load balancers have become a critical infrastructure component for ensuring optimal performance of large Internet or intranet sites. Raw performance numbers are a useful comparison metric, but load balancing and management features and the ability of a system to integrate with different Web infrastructure components should play a more important role when choosing the best solution for the job.

eWeek Labs tested two server load balancers that illustrate some of these differences and how hardware- and software-based systems compare: Radware Inc.s hardware-based Web Server Director Pro 7.10 and the software-based Zeus Load Balancer 1.3 from Zeus Technology Inc.

Hardware-based products usually come in the form of a ready-to-deploy appliance, switch or router and are optimized for the task of load balancing.

An advantage to software-based systems is that IT administrators can install them on any system that will deliver the desired performance. The disadvantage is that these systems arent born to the task and thus may saddle the software with some performance overhead.

To test the performance of Web Server Director Pro and the Zeus Load Balancer, we used Antara.nets Flame-Thrower II Web-stressing tool configured with four server and four client ports to emulate client/server transactions in an HTTP environment.