Report Number: CS-TN-97-41
Institution: Stanford University, Department of Computer Science
Title: Reducing Initial Latency in a Multimedia Storage System
Author: Chang, Edward
Author: Garcia-Molina, Hector
Date: February 1997
Abstract: A multimedia server delivers presentations (e.g., videos, movies, games), providing high bandwidth and continuous real-time delivery. In this paper we present techniques for reducing the initial latency of presentations, i.e., for reducing the time between the arrival of a request and the start of the presentation. Traditionally, initial latency has not received much attention. This is because one major application of multimedia servers is ``movies on demand'' where a delay of a few minutes before a new multi-hour movie starts is acceptable. However, latency reduction is important in interactive applications such as playing of video games and browsing of multimedia documents. Latency reduction is also crucial to improve access performance to media data in a multimedia database system. Various latency reduction schemes are proposed and analyzed, and their performance compared. We show that our techniques can significantly reduce (almost eliminate in some cases) initial latency without adversely affecting throughput. Moreover, a novel on-disk partial data replication scheme that we propose proves to be far more cost effective than any other previous attempts in reducing initial latency.