Aggregated Harmonic Data Placement for Scalable Streaming

Abstract

Internet network bandwidth between Video-on-Demand (VoD) servers and clients may change over time since VoD traffic is mixed with other traffic such as WWW or FTP. If a client grants the variability of Quality-of-Service (QoS) level and a server exploits scalable encoding techniques, the client can be served with a low level of QoS under low network bandwidth circumstances and can be served with a high level of QoS under high network bandwidth circumstances. Since changes of client network bandwidth can incur unexpected disk I/O load, and disk I/O bandwidth is one of the most demanding resources on video servers, these servers need a mechanism for storage management to support heterogeneity in client network bandwidth. This paper presents a video layout scheme for clients with varying network bandwidths called, Aggregated Harmonic Placement. This scheme exploits both parallelism and concurrency offered by distribution of data across disks. Through extensive experiments, we verified the efficiency of the proposed scheme.