Algorithms for Designing Large-Scale Multimedia Servers

In this paper, we propose a novel adaptive admission control algorithm, in which a client is admitted for service by a multimediaserver only if the extrapolation from the past measurements of the storage server performance characteristics indicate that the service requirements of all the clients can be met satisfactorily. Each client may request the retrieval of a variable bit rate (VBR) encoded media stream and may require a different quality of service. We also present a disk scheduling algorithm that minimizes both seek time and rotational latency incurred while accessing a sequence of media blocks from disk. We examine the effects of a finite read-ahead on the quality of service provided to each admitted client. The effectiveness of the admission control and disk scheduling algorithms is demonstrated through extensive simulations.