Impact of Buffer Sharing in Multiple Disk Video Server Architectures

A video server allows to deliver multiple video streams to different clients. To provide the required amount of storage and bandwidth, a video server must contain a large number of disks. Since the retrieval rate of the disk and the consumption rate of the clients differ, the data retrieved from disk need to be temporarily stored in main memory, which is an important cost factor in a video server. Video data must be retrieved from disks in such a way that neither buffer starvation nor overflow occurs for all concurrent video streams. In this paper we calculate the required buffer for the GSS scheduling algorithm for multiple streams retrieved from multiple disk server nodes. We prove analytically that shared buffer management reduces, in comparison with the dedicated buffer management, the required buffer by up to 50%.