File caching in video-on-demand servers

This paper studies the file caching issue in video-on-demand(VOD) servers. Because the characteristics of video files are very different from those of conventional files, different type of caching algorithms must be developed. For VOD servers, the goal is to optimize resource allocation and tradeoff between memory and disk bandwidth. This paper first proves that resource allocation and tradeoff between memory and disk bandwidth is an NP-complete problem. Then, a heuristic algorithm, called the generalized relay mechanism, is introduced and a simulation-based optimization procedure is conducted to evaluate the effects of applying the generalized relay mechanism.