A time-scale dependent disk scheduling scheme for multimedia-on-demand servers

Abstract

We present a producer-consumer model of multimediaon-demand servers, The producer retrieves media data from a disk and places it into a set of buffers while the consumer sends out the data in the buffers to the users. We develope for the producer a time-scale dependent buffer-inventory-hirsed dynamic scheduling scheme named o-BIDS which gunrunteesto meet the continuityrequiremcnt and no-lossof datn for each media stream. The scheme introduces a time-scale dependent peak consumption rate and a virtual cycle time to smooth out the impact of bursty data of variable-bit-raie streams, thus improving the maximum admissible load of requests. A straighlforward admission control mechanism with quality-of-service guarantees is then established based on two simple conditions respectively on loud and bufier size. Our scheduling scheme is very easy to implement, and experiments carried out with an actual disk system and rei11 video stream data verifr the effectiveness of the scheme.