Design and evaluation of a generic software architecture for on-demand video servers

Introduces the design, implementation and evaluation of a generic software architecture for on-demand video servers. We describe different key components for controlling the storage and network devices within the server. The interactive collaborations between these software components are also illustrated. The experimental results indicate a very promising direction in exploring the right combinations of these software components. The server is thus able to increase the number of concurrent video accesses with the same hardware configuration. For instance, with the right combinations, the system achieved about 80% of the storage system bandwidth of four disks, about 70% of the storage system bandwidth of six disks, and generally reached the maximal achieved SCSI bandwidth when eight disks are used over two SCSI buses. Our research and experimental results are based on video servers currently under construction across a variety of hardware platforms, including SMP, DMP and clusters of PCs or workstations. The most advanced prototype server is based on an SGI shared-memory multiprocessor with a mass storage system consisting of RAID-3 disk arrays. With all the enabling/management schemes, we were able to further investigate interesting research issues by considering the user's access profiles for taking advantage of popular video titles. The results were significant, with a range of 60% improvement given a 512 kByte block size. In addition to the experimental results, theoretical performance models were also developed that closely match to our collected experimental results.