MEDIC: a memory and disk cache for multimedia clients

Abstract

We propose an integrated memory and disk cache for managing the resources of a multimedia client's computer or set-top box. The cache cushions the multimedia decoder from input rate fluctuations and mismatches, and because data can be cached to disk, the acceptable fluctuations can be very large. This lets the client operate efficiently at low cost when the network rate is much larger or smaller than the media display rate, and gives the media server much greater flexibility for balancing workload and supporting VCR-like functions. We analyze the memory requirements for this cache, and analytically derive safe values for its control parameters. Using a realistic case study, we examine the interaction between memory size, peak input rate, and disk performance, and show that a relatively modest amount of main memory can support a wide range of scenarios.