An increasing number of shops are putting clustering and load-balancing technologies into place so as to provide high availability and an economic way to scale server capacity. The slender Server Load Balancing explains the state of the art in multiple-server technologies implemented at Layers 4 and 5 on the OSI network model. Though author Tony Bourke includes a fair bit of good information on configuring four commercial load-balancing solutions, the most valuable part of his work is his high-level discussions of how load balancing fits into a larger network environment, and his explanations of the relative merits of alternative approaches to the problem. A comparison of flat-based solutions with designs based on Network Address Translation (NAT) is part of this book's value; further appeal takes the form of dozens of network diagrams that document typical working solutions.

Bourke shows his familiarity with real-life design constraints by documenting various load-balancing solutions and pointing out what each can do for an organization — he points out that a host that implements a NAT-based balancing solution can double as a firewall, thereby saving some money that would have been required for a dedicated security device. He also provides introductory material on the competing solutions' administration interfaces, enabling implementers to get a head start on their work without wading into vendor documentation.