一种层次式的事务工作流失效恢复算法  

A Hierarchical Failure Recovery Algorithm for Transactional Workflows

作　　者：任怡[1] 吴泉源[1] 贾焰[1] 

机构地区：[1]国防科技大学计算机学院博士生队,湖南长沙410073

出　　处：《电子学报》2005年第2期317-321,共5页Acta Electronica Sinica

基　　金：国家自然科学基金项目 (No.90 1 0 4 0 2 0 ) ;国家 863重点课题 (No .2 0 0 1AA1 1 30 2 0 )

摘　　要：部分补偿和完全补偿是事务工作流失效恢复的传统补偿方法 ,对于长期运行且结构复杂的事务工作流 ,失效时需要补偿至静态定义的某一活动甚至起始活动 ,因此代价较大 .给出了事务工作流的概念模型 ,提出了一种层次式的失效恢复算法 .与传统方法相比 ,允许事务性或者非事务性子过程同时存在 ;将工作流看作由嵌套结构的子过程组成 ,而不是一个平坦流图 ;基于执行历史而不是工作流定义进行补偿 ,可简化循环结构的恢复 .该算法针对活动的恢复策略进行层次式的向上规约处理 ,动态确定补偿终止点 ,可有效减小补偿域 .证明了算法的正确性 ,性能分析表明其性能通常优于非层次的失效恢复算法 ,讨论了算法的实现 .Partial compensation and complete compensation are two common failure recovery methods for transactional workflows.For complex structured long running transactional workflows,the compensation cost may be unacceptable since the workflow must be reversed to a previously defined activity or even to the start point to ensure semantic atomicity.We presented a conceptual model for transactional workflow.Based on the model,we proposed a hierarchical failure recovery algorithm.Different from traditional methods,it supports both transactional and non transactional sub processes,and sub processes of a workflow are nestedly structured.The algorithm determines the end compensation point dynamically in a hierarchical bottom up manner,so the compensation sphere is confined and compensation costs are reduced.We proved the correctness of the proposed algorithm.Performance analyses showed that it is more preferable than non hierarchical methods.The algorithm has been applied into InforFlow,a workflow management system prototype.The implementation issues were illustrated.

关 键 词：事务工作流 失效恢复 层次式 补偿 

分 类 号：TP311[自动化与计算机技术—计算机软件与理论]