区块链共识窗口下Web服务兼容性评价方法  

Method for evaluation of web services compatibility based on the blockchain’s consensus algorithm

作　　者：马诗洋 董学文[1] 权义宁[1] 佟威 杨凌霄 MA Shiyang;DONG Xuewen;QUAN Yining;TONG Wei;YANG Lingxiao(School of Computer Science and Technology,Xidian University,Xi’an 710071,China)

机构地区：[1]西安电子科技大学计算机科学与技术学院,陕西西安710071

出　　处：《西安电子科技大学学报》2020年第5期63-69,共7页Journal of Xidian University

基　　金：国家重点研发计划(2017YFB1400700);陕西省重点研发计划(2019ZDLGY13-01,2019ZDLGY12-03);国家自然科学基金(61972310)。

摘　　要：针对传统的服务计算框架下,web服务的性能评价缺乏时效性且缺乏服务兼容性能评价方法的问题,提出了一种基于马尔科夫链和共识时间窗口的兼容性能评价方法。首先,提出增强型面向服务架构计算框架,利用区块链共识算法产生时间较为固定的特点,将时间分隔成长度固定的时间窗口,从而产生服务性能的“时效性”。其次,提出服务兼容性能评价方法,利用当前时段服务池调用记录,计算出能够预测服务下一时段服务兼容性的参数“连接值”。最后,选取4种共识算法BitCoin PoW、PPCoin DPoS、Fabric PBFT以及PBFT+DPoS,对这4种共识算法产生的时间窗口下服务池的离散程度、连接值的分布、兼容性能评价效果进行了对比。结果表明,笔者提出的计算模型,可以准确地区分服务池内服务的兼容属性,区分度随区块链共识算法改变,效果排名依次是PoW,PBFT,DPoS,PBFT+DPoS。In the traditional Service Oriented Architecture(SOA),evaluations of services are results from accumulated remarks,which means that they lack real-time feedbacks.In this paper,we propose an advanced architecture combined by SOA and block-chain.We take the advantage of the stable time-slot generated by the consensus algorithm to clock the service pool,making it possible to evaluate the real-time states of services.Moreover,we propose a mathematical model based on the Markov Chain to assess and predict the compatibility of a service in a time-slot.And we assess and evaluate the distribution of compatibility by bringing in four well-known consensus algorithms(Bitcoin’s PoW,PPCoin’s DPoS,Fabric PBFT,PBFT+DPoS)which generate different lengths of time-slots.The result shows that our compatibility assessment model works well and that the distribution varies with different consensus algorithms with the rankings of effects as follows:PoW,PBFT,DPoS,and PBFT+DPoS.

关 键 词：区块链 共识算法 服务组合 兼容性能 马尔科夫过程 

分 类 号：TP393[自动化与计算机技术—计算机应用技术]