一种边缘计算环境下降低副本一致性难度的副本放置方法  

A Replica Placement Method to Reduce the Difficulty of Replica Consistency by Replica Placement in Edge Computing

作　　者：高倩[1] 孙胜耀 乔保军 左宪禹[3,4] GAO Qian;SUN Shengyao;QIAO Baojun;ZUO Xianyu(Henan Police College,Zhengzhou 450046,China;Zhengzhou Normal University,Zhengzhou 450044,China;Henan Key Laboratory of Big Data Analysis and Processing,Henan University,Henan Kaifeng 475004,China;School of Computer and Information Engineering,Henan University,Henan Kaifeng 475004,China)

机构地区：[1]河南警察学院,郑州450046 [2]郑州师范学院,郑州450044 [3]河南省大数据分析与处理重点实验室,河南开封475004 [4]河南大学计算机与信息工程学院,河南开封475004

出　　处：《河南大学学报（自然科学版）》2022年第6期681-689,共9页Journal of Henan University:Natural Science

基　　金：国家重点研发计划-国际科技创新合作专项(2019YFE0126600);河南省重大科技专项(201400210300);河南省重点研发与推广专项(科技攻关)项目(212102210393)。

摘　　要：在边缘计算中,副本放置可以有效地均衡边缘服务器的负载,降低终端用户的访问延迟.传统的副本放置方法多侧重于改善系统的性能,较少关注在副本放置时降低副本一致性的难度,导致放置过多的副本增加了副本一致性的难度.为应对该问题,本文提出了一种边缘计算环境下缓解副本一致性难度的副本放置方法(简称RPCD),实现均衡边缘云节点负载、降低终端访问延迟并降低副本一致性难度的目标.RPCD由边缘云服务器采用分散自适应的方式动态创建和放置副本.该方法选择高流行度、低更新率的数据对象创建副本,并根据边缘云服务器的负载、边缘云的拓扑结构以及数据的反应延迟,绘制了更新风险图来对边缘服务器进行评估,最后根据评估结果选择合适的边缘云服务器放置副本.实验证明,与同类方法相比,RPCD能够较好地均衡系统负载并降低数据访问延迟,同时还可以有效地降低副本一致性的难度.In edge computing, replicas placement can effectively balance the load of edge servers and reduce the access delay of end users, but more replicas increase the difficulty of replica consistency. Traditional replica placement methods pay more attention to improve the performance of the system and no focus on reducing the difficulty of replica consistency during replica placement. To deal with this problem, this paper proposes a replica placement method to reduce the difficulty of replica consistency by replica placement in edge computing, named RPCD, aiming to balance the load of edge cloud nodes, reduce the terminal access delay and reduce the difficulty of replica consistency. RPCD can dynamically create and place replicas in a decentralized adaptive manner. It selects data with high popularity and low update rate to create replicas, and plots the update risk map according to node load, node degree and access delay to select optimal nodes to place replicas according to the update risk level. Extensive experiments show that RPCD can better balance the system load and reduce the data access delay, and can effectively reduce the difficulty of replica consistency than other similar methods.

关 键 词：边缘计算 边缘云 副本策略 副本一致性 访问延迟 

分 类 号：TP311[自动化与计算机技术—计算机软件与理论]