A replication strategy for reducing wait time in video-on-demand systems

Abstract

User wait time-the amount of time a user spends in waiting for a video to commence-is an important service parameter in many video-on-demand (VOD) systems. In a companion paper (T.S. Chua, J. Li, B.C. Ooi, and K.L. Tan, in Proceedings of the ACM Multimedia '96, Boston, 1996, pp. 297-306), we have proposed a Phase-based Striping Method in which a video can be placed on multiple disks to take advantage of their combined bandwidth. In this paper, we extend the Phase-based Striping Method with a replication strategy aimed at reducing the average user wait time. To provide evidence for the effectiveness of the proposed strategy, we conducted extensive simulations of a video server under different loading and hardware configurations. Our results demonstrate that replication can lead to substantial reduction in average wait time.