摘要： 在参与者服务发生异常时，如何有效保证组合服务的服务质量(QoS)是一个亟待解决的问题。该文讨论组合服务在执行过程中动态QoS的计算，建立一个组合服务嵌套事务模型，提出一个组合服务事务恢复算法。该算法能将补偿的范围控制在低层的域内，以减少补偿代价，保证QoS接近最优，同时保证组合服务事务的语义原子性。

关键词: Web服务, 组合服务, 事务, 服务质量

Abstract: It is an urgent problem that how to insure QoS of composite service effectively when exception happens in participant service. This paper discusses the dynamic calculation of QoS when composite service is running, builds an embedded transaction model of composite service and presents a transaction recovery algorithm of composite service. The algorithm can keep the area of compensation in a lower scope, reduce the cost of compensation, and insure QoS approach to the best when transaction recovering and relaxed atomic of transaction-semantic atomic.

Key words: Web service, composite service, transaction, QoS

中图分类号: 

• TP301.6