基于Saga模型的事务工作流实现机制

基于Saga的事务工作流实现机制结合了扩展事务模型和Saga事务模型的特点.当任务执行出现异常时,需清除已执行任务产生的影响后才能终止任务的执行,其前向恢复通过异常控制机制实现,后向恢复则通过事务补偿实现.在事务全部处于初始化状态时启动工作流流程,每个活动被依次选择执行并返回其代码,若全部成功执行则结束,若执行发生异常则后向恢复模块有效,进入事务控制模式.并构造了采用该事务工作流实现机制的工作流引擎.

Implementing Mechanism of Transaction Workflow Based on Saga Model

Implementation mechanism of transaction workflow based on Saga has both the features of the extended transaction model and Saga transaction model. If exception occurs when executing task, it is required to clear influence of executed task and terminate the execution of task. Its forward recovery is realized with exception control mechanism, and backward recovery is realized with transaction compensation. Start workflow process when transactions are at the initial state, and each activity is selected to execute in turn and return a code, then all activities were executed successfully and terminated. If occurred exception, backward recovery module is valid and execute in transaction control model. And workflow engine was built up with transaction workflow implementation mechanism.