BiHOP: a bidirectional highly optimized pipelining technique for large-scale multimedia servers

We present a technique, called bidirectional highly optimized pipelining (BiHOP), for managing disks as a buffer for the tertiary storage of a multimedia server. We implement a simulator to compare its performance to that of a recently proposed scheme called SEP. The results show that BiHOP performs significantly better. Its superior performance is attributed to a novel caching approach, which caches every other data fragment of the multimedia file, rather than caches consecutive fragments as in traditional practice. This new approach allows us to use tiny staging buffers for pipelining, which can be implemented in the memory to conserve disk bandwidth. Furthermore, the whole disk space can be dedicated for caching purposes to improve hit ratio. Another important advantage of BiHOP is its ability to pipeline in either forward or reverse direction with the same efficiency. This unique feature, not possible with existing schemes, makes it natural for implementing VCR functions.