Research And Implementation Of Workflow Transaction Processing Based On BPEL

Workflow technology is an effective means of automating business processes. The research and development of workflow technology has great significance to promote business process to be more practical. Traditional workflow models are lack of support for transaction. It can't meet the requirement of modern business process management any more. How can we unify the workflow technology and transaction processes, to enhance the stability and reliability of workflow management system is a question to be solved urgently.This thesis makes a detailed study on the characteristics of advanced transaction model and transaction handling technology. Then it provides an idea of introducing transaction to existing workflow model. This thesis brings forward a workflow transaction processing model named WMBT (Workflow Model Based on Transaction) which based on the Transaction-Oriented Workflow Activity Model and BPEL (Business Process Execution Language). WMBT is the workflow model with transactional characteristics that we propose. To support transaction processes well, in WMBT, we propose a conception of transaction semantics. WMBT classifies the transactions more according to their semantics characters. In this way, users can deal with different transactions more flexibly. Besides that, we propose a two-level model based on transaction, which is a recovery-and-execution model. Its goal is to let transactions have relaxed atomicity in a suitable transaction sphere. In the transaction sphere we provide the rules for transaction recovery to guarantee the workflow process to be correct and consistent. And we propose a group of modes to deal with failed transactions more effectively, in order to meet the needs of different situations.After a study on exception handling technology in workflow, we introduce a systematic method to handle expectable and unexpectable exception. After analyzing the causes of the failures in workflow system, we compartmentalize these failures according to their types. We extend ECA (Event-Condition-Action) rules, based on the extential ECA rules, we present transaction recovery algorithm which is more flexible. This algorithm based on not only the extential ECA rules, but also the business processes, so it confines the compensation sphere and reduces the compensation costs.After that, we have implemented WMBT. WMBT has the abilities of handling long-running transaction and exception. In the end, we present the results of experiments on the effect and efficiency of transactions in WMBT. The experimental results show that WMBT can deal with transactions, as well as exceptional transactions, effectively and favorably.