基于隔离域的事务工作流并发控制

事务工作流系统中存在多个流程的多个实例同时并发执行的情况,所以多个活动同时访问共享资源时出现访问冲突.为保证流程的正确执行和提高活动的并发度,基于事务的隔离性特征,提出了隔离域的概念和相关属性,并在建模阶段采用业务流程和事务需求分开定制的方式,通过设置隔离域的隔离属性来控制各流程实例并发活动的执行,并且给出了基于隔离域的并发控制算法,从而有效地提高了流程和活动的并发度,并避免丢失修改等现象的发生.

Transactional workflow concurrency control based on isolation spheres

In transactional workflow systems there are many workflow instances(belonged to the same workflow schema or the different ones) could be running simultaneously,so many activities would be conflict to access the shared resources.In order to insure the cor-rectness of the workflow execution and increase the concurrency,the conception of isolation and the interrelated attributes based on the isolation of transactional workflow is presented.The way we choose to tackle this problem consists in separating concern between the process definition and its transactional requirements,control the concurrent execution of the activities by define the isolation level,and present the concurrency arithmetic,so improve the concurrency of processes and activities,and avoid the lost update phenomenon.