Replica striping for multi-resolution video servers

Multi-resolution video compression techniques are used for the efficient support of heterogeneous clients with different quality of service (QoS) parameters. However, data rates for high- and low-resolution video streams can vary Widely; so the number of admitted clients may be limited due to the unbalanced use of server resources (i.e., disk bandwidth and buffer). Thus, the server may not accommodate new users although there is sufficient buffer or disk bandwidth. To remedy this problem, we propose a new replication scheme called Splitting Striping units by Replication (SSR) for multi-resolution video servers. To increase the number of admitted clients, we define-two striping unit sizes of data which are stored on the primary and backup copies in different ways. In addition, we present a new admission control algorithm which adaptively decides whether to read data from the primary or the backup copy in order to make the best use of disk bandwidth and buffer of the video server. The effectiveness of the proposed scheme is evaluated through simulations.