An efficient data retrieval scheme to improve service capacity of a VBR video server

The variable bit rate (VBR) nature of a video stream makes it difficult to build up a video server since that the amount of system resources supporting a VBR stream is time-variant. This property results in poor utilization of system resources due to the fact that a VBR video server may be overloaded at some critical times but under-utilized frequently. An efficient data retrieval scheme for VBR video servers is presented in this paper. The basic concept behind the scheme is that we can efficiently utilize the disk bandwidth by using read-ahead and buffering techniques. Then, irregular resource usage of a VBR video server can be alleviated and the service capacity can thus be promoted. According to experimental results, we find that the proposed scheme can improve by 8%-20% the number of served users of a VBR VOD system compared to the original method with less than 6% additional buffers.