Single Pair of Buffers: Reducing memory requirements in VBR media servers
Most Video-on-Demand scheduling models are focused on the optimization of disk and network utilization, paying less attention to memory management. In this paper we present, analyze and evaluate a new buffering policy, namely Single Pair of Buffers, which greatly reduces Video-on-Demand server memory requirements when used in combination with any cycle-based scheduling algorithm. This technique is based on the synchronization of a single pair of buffers per storage device, as opposed to existing solutions based on per-stream buffering allocation. The influence of factors such as Variable Bit Rate streams, zoned disks, network speed and cycle length has been considered in detail. Extensive simulation results show that Single Pair of Buffers leads to more than one order of magnitude memory reduction when compared to the popular double-buffering approach, at a cost of a minor (less than 2% in the worst case) performance degradation.
Unable to display preview. Download preview PDF.
- 1.Bolosky. W. J. et al. The Tiger Video Fileserver. Proc. NOSSDAV. Zushi, Japan (1995).Google Scholar
- 2.Bernhardt, C, Biersack, E. The Server Array: A Scalable Video Server Architecture. Chapter 5 in “High-Speed Networking for Multimedia Applications. Eds. Kluwer. (1996).Google Scholar
- 3.Berson, S., Muntz, R. R. Just-in-time Scheduling for Video-on-Demand Storage Servers. Technical Report, UCLA Computer Science Department. (1995).Google Scholar
- 5.Chen, M.-S., Kandlur, D. D., Yu, P. S. Optimization of the Grouped Sweeping Scheduling (GSS) with Heterogeneous Multimedia Streams. Proceedings of the ACM Multimedia Conference, Anaheim, CA (1993) 235–242.Google Scholar
- 6.Ghandeharizadeh, S., Stone, J., Zimmermann, R. Techniques to Quantify SCSI-2 Disk Subsystem Specifications for Multimedia. Technical Report TR 95-610. University of Southern California (1995).Google Scholar
- 7.García-Martínez, A., Fernández-Conde, J., Viña, A. Efficient Memory Management in VOD Disk Array Servers Using Per-Storage-Device Buffering. To appear in Proc. of the IEEE Euromicro Workshop on Multimedia and Telecommunications (1998).Google Scholar
- 8.Garrett, M. and Willinger, W. Analysis, Modeling and Generation of Self-Similar VBR Video Traffic. Proc. ACM SIGCOMM (1994) 269–280.Google Scholar
- 9.Gemmell, J., Vin, H. M., Kandlur, D. D., Rangan, P. V. Multimedia Storage Servers: A Tutorial. IEEE Computer Magazine, Vol. 28, n‡ 5 (1995) 40–49.Google Scholar
- l0.Johnston, W. et al. Distributed Large Data-Object Environments: End-to-End Performance Analysis of High Speed Distributed Storage Systems in Wide Area ATM Networks. Proc. NASA/Goddard Conference on Mass Storage Systems and Technologies (1996).Google Scholar
- 11.Neufeld, G., Makaroff, D., Hutchinson, N. Design of a Variable Bit Rate Continuous Media File Server for an ATM Network. Proc. Multimedia Computing and Networking Conference, San Jose, CA (1996).Google Scholar
- 12.Ng, R. T., Yang, J. An Analysis of Buffer Sharing and Prefetching Techniques for Multimedia Systems. Multimedia Systems 4 (2). Springer-Verlag (1996) 55–69.Google Scholar
- 13.Rose, O. Statistical Properties of MPEG Video Traffic and Their Impact on Traffic Modelling in ATM Systems. Technical Report TR-101, Institute of Computer Science, University of Wuerzburg (1995).Google Scholar
- 14.Tobagi, F., Pang, J., Baird, R., Gang, M. Streaming RAID — A Disk Array Management System for Video Files. Proc. ACM International Conference on Multimedia. Anaheim, CA (1993) 393–400.Google Scholar