Maximizing the performance of Unix systems is a challenge that requires a specialized understanding of operating system behavior, knowledge of the design and tuning capabilities of the applications that run on the system, and an intimate acquaintance with system and application performance measuring tools that assist in tuning. Operating system behavior changes as improvements are made for scalability and significant new features are added. New hardware designs offer the potential for improved performance when the operating system and application takes advantage of the new designs. The behavior of applications can change not only with new versions of the application itself, but also with new versions of the underlying operating system.

Although application design and tuning is crucial to getting the best possible performance, the number of applications and application vendors are so numerous that it is impractical to discuss specific application tuning in detail. Therefore, this book focuses on Hewlett-Packard's HP-UX Operating System and the HP 9000 and Integrity Systems on which it runs. This edition adds significant content on networking, Java, new hardware designs, especially Itanium Processor Family (IPF) designs, and HP-UX 11i-specific performance issues. The authors are most familiar with HP-UX, and therefore, the specific operating system architecture and tuning suggestions presented in this book apply directly to HP-UX. The authors also have experience working with a variety of applications and provide guidance on tuning based on their knowledge of how applications and the system interact.