The Research And Design Of Workflow Exception Based On Transaction

The workflow system has become more and more important in people’s day-to-day business, introduce in the workflow the transactional characteristics makes workflow system has the ability to recover quickly after the failure of the task execution. Based on the workflow in practical application process complexity, long operating cycle, may be provided with a variety of peripheral procedures and human interaction, the possibility of abnormality appears becomes large, increasing workflow exception handling capability becomes crucial.Based on research of workflow transaction this paper aims to optimize workflow exception handling. The main work includes:(1)Proposed an improved Sagas transaction pattern, so when a task is wrong it can do the compensate transactions to roll back to a balance point, and continue the workflow process. Instead of do all the compensate transactions and get back to the start state, so it saves the resource and the time.(2) Based on the research of the workflow transaction, proposed a strategy of exception handling optimization. This paper describes how to design and implement the transactional workflow explicitly, proposingthe basic framework of transaction-processor and give the design ideas and methods of the core function of transaction-processor.(3) Design and implement the roll back function of the workflow. Give the logic framework and process of the roll back function, extend the XPDL process design language, change the workflow engine to deal with the roll back. Describe the use of the packages and classes, and the data base. Finally design a workflow process and run it, it shows the roll back function runs well.