On Mixed-Workload Multimedia Storage Servers with Guaranteed Performance and Service Quality

An important issue in multimedia information systems that has received considerable attention is to provide performance and service quality guarantees for "continuous" streams of video/audio data, especially bounding the rate of non-timely data fragments, so-called "glitches", under a given number of concurrently served streams. An equally important but much harder problem that has been neglected so far is to extend such guarantees to a mixed workload with both continuous-data streams and response-time-sensitive requests to conventional, "discrete" data. This paper develops an analytic performance model for such a mixed workload. The model is a hierarchical one, where the higher, macroscopic level addresses the mutual performance impacts of continuous-data and discrete-data requests by means of an abstract Markov process model, and the lower, microscopic level analyzes the glitch rate under a detailed disk model. A configuration method for mixed-workload multimedia storage servers on t...