基于萤火虫优化的副本放置方法

在云计算环境下分布式存储系统中，通常采用副本技术保证存储系统的可用性和可靠性，放置策略是副本技术的一个关键问题。针对现有副本放置策略中存在的副本访问开销大的问题，提出一种基于离散型萤火虫优化的副本放置算法。考虑副本放置对用户访问性能的影响，对其建立数学模型，计算萤火虫位置的适应度函数，并朝着荧光素值最大即最优值移动，进而得到合适的副本放置节点。通过仿真实验评估提出的方法，并与基于蚁群算法的副本放置策略进行比较。实验结果证明该算法能够选择合适的副本放置节点，具有较好的收敛性，并有效地降低存储系统的副本访问开销。

Replica placement strategy based on glowworm swarm optimization

Cloud storage system often adopts replica technique to guarantee availability and reliability, and replica placement is a key issue. In order to solve the problem of high access overhead to replicas, this paper proposed a replica placement algorithm based on discrete glowworm swarm optimization. Through mathematical mode establishment for user access overhead, this algorithm computed the fitness function of glowworm position, updated individual position and then obtained appropriate nodes for replica placement. It conducted several simulations and compared with the replica placement strategy based on ant algorithm. The results show that the proposed algorithm can select appropriate nodes for replica placement, have a better convergence and reduce the replica access overhead.