支持组合事务的失败恢复验证

Verification of failure recovery for composition transaction

组合事务中任务间的协作通常以点对点的方式而不是中心控制,当系统崩溃时,事务流中的任务可能部分执行而其后续任务则未被调度执行。在这种情况下,选择合适的失败恢复验证策略是必要的。提出一种支持向前、向后和替代恢复策略的失败恢复验证方法。当失败发生时,借助组合事务的执行日志和可接受状态集,选择合适的恢复策略,验证带状态空间的事务恢复所产生的一组动作序列,是否包含一组良好行为。追踪执行进展,检测恢复后组合事务是否存在不一致状态。通过对旅行预订流程的实例分析,表明该失败恢复验证方法是可行的。

Since tasks collaborate progresses in a point-to-point way instead of the central control in composition transaction,some tasks of the transaction flow may be committed and their successors unscheduled when a composition transaction system carsh occurs.In this situation,selecting an appropriate verification strategy for failure recovery is critical.Then a failure recovery verification strategy for forward recovery,backward recovery and alternative recovery is proposed.When failure occurs,according to the execution log and acceptable state set of composition transaction,the appropriate recovery stategy is selected,which verifies whether action sequences generated during execution of failure recovery with state space contains a set of good behaviors and whether consistency states after recovery can be checked by keeping track of the execution progress.Finally,the classical travel reservation process（TRP） is analyzed.The results show the feasibility of the proposed verification strategy.