关键词: 树形网络, 副本放置, 多访问策略, 更新

Abstract: Replica technology is widely applied in cloud computing and distributed systems, the reasonable data replica placement is an important means to reduce the operation cost of network, and is also the key issue of replica technology. Replica update is that the replicas are added and deleted when data access requirements dynamically change. Based on multiple policy, this paper proposes a dynamic updating algorithm named MPFSF (min_placement far servers first) to solve the update problem. According to the need to implement the necessary replica update, this paper reuses as much as possible the pre-existing replicas and maximizes the capacity of each replica to reduce the date access latency and improve the efficiency of data access, by adding the constraint of communication distance. The experimental results show that, for the proposed algorithm with update policy, the running cost of the network gets a considerable reduction under the different distance limits, and the best improvement is up to 84.6% in comparison to the state-of-the-art.

Key words: tree network, replica placement, multiple policy, update