Replica placement study in large-scale cloud storage system

Abstract

In the large-scale cloud storage system based on copy redundancy,previous layout algorithm can only partially meet the requirements of high reliability,high scalability and high efficiency in the replica layout.To solve this problem,this paper proposed a Replica Placement algorithm based on Grouping and Consistent Hashing(RPGCH).The storage nodes were classified into different groups by their correlativity,then the replicas of one object were assigned in different groups by consistent hashing algorithm,after that each replica was placed into corresponding storage node in the group by consistent Hashing algorithm.The theoretical analysis proves that the reliability of data is improved.The simulation results show that RPGCH can assign data evenly among storage nodes and adapt well with the changing scale of cloud storage system.Moreover,RPGCH is time efficient with little memory overhead.