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. 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. 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 organisation--he points out that a host that implements 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. --David Wall

Topics covered: The problems presented by requirements for high availability and failover, and the solutions that server load balancing can provide. In addition to general information on flat--and NAT-based load balancing solutions--this book documents strategies for implementing Alteon WebSystems, Cisco CSS, F5 BIG-IP, and Foundry ServerIron.