A prefetching method with Double-Buffer for multimedia streaming servers

The low throughput of storage devices is constraining the improvement of performance for multimedia streaming systems. After analyzing mechanical structure of disks, we found that massive and sequential reading/writing is an effective approach to increase the throughput. Meanwhile, most users are used to sequentially playing video according to the statistic from current systems. Based on the feature of disks and the behavior of users, this paper proposed a prefetching method, which will read ahead massive data sequentially and cache it in the structure of Double-Buffer, to improve the performance of disks for multimedia streaming servers. For Double-Buffer, Random Refilling Policy and Statement Concerned Policy are applied to balance the load of disks. This paper also studied the optimization of one buffer's size and the method's performance under the condition of high CPU utilization. The final simulation result indicates that the disk's throughput with prefetching method is greatly higher than that without prefetching.