An experimental analysis of digital video library servers

Much work on video servers has concentrated on movies on demand, in which a relatively small number of titles are viewed and users are given basic VCR -style controls. This paper concentrates on analyzing video server performa nce for non-linear access applications. In particular, we study two non-lin ear video applications: video libraries, in which users select from a large collection of videos and may be interested in viewing only a small part of the title; and video walk-throughs, in which users can move through an ima ge-mapped representation of a space. We present a characterization of the w orkloads of these applications. Our simulation studies show that video serv er architectures developed for movies on demand can be adapted to video lib rary usage, though caching is less effective and the server can support a s maller user population for non-linear video applications. We also show that video walk-throughs require extremely large amounts of RAM buffering to pr ovide adequate performance for even a small number of users.