多级存储结构视频点播系统中的接纳控制算法研究

Study of Acess Control Algorithm in Hierachical Storage VOD Systems

0引言 视频服务器作为视频点播(VOD)系统的核心,需要存储和管理大量经过压缩的视频节目.一方面,为了向用户提供实时、并发的视频流,需要使用高速的磁盘阵列来存放节目,但价格非常昂贵.另一方面,不同的节目受观众的喜爱程度不同,将点播频率极小的节目存放于价格昂贵的磁盘阵列中是不经济的.因此,有必要使用分级存储方案[1,2],即将不常被点播的节目存放到磁带库或光盘库等相对廉价的大容量存储设备中去,作为非在线节目,通常这部分存储称为二级库.

As the core of VOD system.video servers need a large storage copacity. Therefore.a hierachical storage structure is inevitable. As a result,it's an urgent problem to find a suitable access control algorithm for VOD system based on hierachical storage structure. In my thesis, an unfair access control algorithm based cost factor is discussed. The computer simulation of the performance of this algorithm is shown,and satisfied results are achieved.