基于Sagas模型的改进事务工作流模型  

AN IMPROVED TRANSACTIONAL WORKFLOW MODEL BASED ON Sagas

作　　者：严刚[1] 陈英[1] 

机构地区：[1]上海交通大学计算机科学与工程系,上海200240

出　　处：《计算机应用与软件》2010年第3期149-151,190,共4页Computer Applications and Software

摘　　要：Sagas模型要求所有子事务都要有对应的补偿子事务,任何子事务失败必须强制其它所有子事务失败,不能很好支持多事务多实例的并发执行。这三个缺陷使得Sagas模型至今不能运用到商业工作流系统中。针对Sagas模型的缺陷,提出一种改进的Sagas事务工作流模型,对子事务属性进行了分类并通过构造子事务间的关联关系使得可补偿子事务失败时无需强制所有子事务失败;引入补偿服务完善了工作流模型的语义;给出了基于事务实例锁集和后继子事务类型集的多事务多实例并发运行算法。该模型解决了Sagas模型存在的问题。There are three limitations in Sagas model： all sub-transactions must have the corresponding compensable transactions; any subtransaction failure will make all other sub-transactions fail mandatory; cannot support concurrency execution of multiple transactions and instances well. Due to these reasons the Sagas model didn＇ t be applied to business workflow system up to now. We propose an improved Sagas transactional workflow model against these limitations, in it the transaction properties are classified and the correlative relationship between sub-transactions is constructed to make it possible that the compensable sub-transaction failure won＇ t cause all other sub-transactions fail mandatory. By introducing a compensation service the semantic of workflow is enriched ; the concurrency operation algorithm of multiple transactions and instances based on transaction instance lock set and posterior sub-transaction type set is introduced as well. The model solves the existing problems of Sagas model.

关 键 词：工作流 Sagas事务模型 事务属性 可补偿事务 并发控制 

分 类 号：TP399[自动化与计算机技术—计算机应用技术]