BIB-VERSION:: CS-TR-v2.0
          ID:: STAN//CS-TN-98-79
       ENTRY:: July 22, 1998
ORGANIZATION:: Stanford University, Department of Computer Science
       TITLE:: 2D BubbleUp: Managing Parallel Disks for Media Servers
        TYPE:: Technical Note
      AUTHOR:: Chang, Edward
      AUTHOR:: Garcia-Molina, Hector
      AUTHOR:: Li, Chen
        DATE:: July 1998
       PAGES:: 24
    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.
       NOTES:: [Adminitrivia V1/Prg/19980722]
         END:: STAN//CS-TN-98-79