分布式多媒体存储系统中的全局缓存管理

多媒体存储系统必须同时支持连续媒体和非连续媒体的访问.由于连续媒体的实时要求,系统必须为访问连续媒体保留大量的磁盘带宽,并且持续很长的时间,这使其他类型文件的访问性能严重下降.本文根据连续媒体的访问特性,提出了一个分布式多媒体存储系统的协同缓存策略GLNU,充分利用系统中其他结点上可用的内存资源,提高缓存的利用率,以减少连续媒体的磁盘I/O,从而提高其他媒体的访问性能.仿真试验表明GLNU在各种不同的参数下,均优于现有的缓存策略,是一种适合分布式多媒体存储系统的缓存策略.

Global Memory Management in Distributed Multimedia Storage Systems

Multimedia storage systems need to handle continuous media data and conventional types of data. Continuous media data access requires high I/O rates and tends to last for a relatively long period of time. However this can drasticaly degrade the performance of accesses to other data types. A new cooperative caching policy called GLNU suitable for the access to continuous media is proposed in the distributed multimedia storage systems. Simulation results indicate our new policy outperforms other cache management policies and greatly improves the cache hit rate and thus reduces the disk I/O for continuous media data.