Remove Multimedia Server Bottleneck by Network Attached Disk Array with Heterogeneous Dual Channels

Multimedia service is pervasive on the Internet now and continues to grow rapidly. Most multimedia service provider systems have adopted a typical system architecture in which the storage devices are attached privately to the server. When a client browses some multimedia data from the server, data should be fetched from the storage devices and then forwarded to the client by the server. Unfortunately, with the steady growth of Internet subscribers, the multimedia server quickly becomes a system bottleneck. Network attached Disk Array is proposed to solve the bottleneck problem. There are two different channels in the disk array. One is a traditional peripheral bus to make the disk array work as a normal storage system. And the other is network interface to transfer data between clients and the disk array directly. The architecture avoids expensive store-and-forward data copying between the multimedia server and storage devices when clients download/upload data from/to the server. The latency is less than that with the traditional architecture and the average data transfer rate is higher. The system performance of the proposed architecture is evaluated through a prototype implementation based on the logical separation in the File Transfer Protocol. In multi-user environment, its data transfer rate is 2~3 times higher than that with a traditional disk array, and service time is about 3 times shorter. The most salient feature of the architecture is that it eliminates the server bottleneck, while dynamically increasing system bandwidth with the expansion of storage system capacity.