Designing a Server Array System for Multimedia World-Wide-Web Services

In [1] we reported the design and implementation of a video-on-demand (VOD) system using a server array architecture. In this paper, we extend the work into a full multimedia server array system for world-wide-web services. The system allows stream-type services such as video and audio guaranteed continuous service irrespective of the background data traffic. The server array approach has the benefits of (1) more system capacity, as individual server has individual CPU, disk, and network channels, (2) scalable, as the system capacity increases with the number of servers without the need for data duplication, and (3) fault tolerant, as server-level fault-tolerant schemes can be devised for sustaining service even if a server fails. We describe the design and implementation of our WebArray system a server array software system developed for multimedia world-wide-web services. Our implementation employs integrated scheduling at the disk and network subsystems to ensure the continuous delivery of video and audio.