This paper describes a continuation of an effort to study the relationship among performance, security, and availability in a Web-based electronic commerce system. In the first phase of the study, we examined the relationship between performance and security, and characterized the performance costs of various encryption approaches. In the second phase of the project, we built a three-tier testbed electronic commerce system, using a cluster of servers at each tier. We characterize the performance of the system under different configurations and under different workloads. We demonstrate the performance advantages of a clustered design, and also discuss the improvements in availability provided by clustering. The paper also discusses some implementation issues, and describes changes in implementation between the first and second phases of the project, and the effect of those changes on performance.