2D BubbleUp: Managing Parallel Disks for Media Servers

Abstract

2D BubbleUp: Managing Parallel Disks for Media Servers Edward Chang, Hector Garcia-Molina, and Chen Li Department of Computer Science, Stanford University echang,hector,chenlig@cs.stanford.edu Abstract In this study we present a scheme called two-dimensional BubbleUp (2DB) for managing parallel disks in a multimedia server. Its goal is to reduce initial latency for interactive multimedia applications, while balancing disk loads to maintain high throughput. The 2DB scheme consists of a data placement and a request scheduling policy. The data placement policy replicates frequently accessed data and places them cyclically throughout the disks. The request scheduling policy attempts to maintain free "service slots" in the immediate future. These slots can then be used to quickly service newly arrived requests. Through examples and simulation, we show that our scheme significantly reduces initial latency and maintains throughput comparable to that of the traditional schemes. Keywords: multimedia, data replication, initial latency, disk array.