Introduction

As the demand for faster and more scalable web service increases, computer system designers have discovered ways to improve web server performance and scalability by integrating web server functionality into operating systems. This trend began with system designers adding system interfaces specifically designed for web servers. Hewlett Packard's Network Server Accelerator HTTP (NSA HTTP) is an architecture that provides an in-kernel cache of web pages in HP-UX 11i. This paper describes the performance improvements achievable with NSA HTTP, and the system tuning needed to achieve these performance improvements.