The Research on Dynamic Replication and Placement of File Using Dual-Threshold Dynamic File Migration Algorithm

The replication and deployment of media file is one of the key issues in video-on-demand system, the replication algorithm and deployment strategy will directly affect the performance of storage balance and load balance in the system. In order to enhance the capacity of streaming media servers and handle the problem that migrating files will affect acceptance rate of user requests, in this paper we present a practical strategy to deploy and transfer files in real video-on-demand system. According to this strategy, we compute the migration probability when a file migration request comes, then we decide whether transfer files by the probability. Through analysis of experimental results and theoretical proof, the dual-threshold dynamic file migration algorithm described in this paper can improve acceptance rate of user requests and the capacity of streaming media servers.