Research Of Long-Lived Transaction Management Based On Automatically Generated Compensation Under The Web Services Environment

The development of Web Services makes it possible to integrate applications of different enterprises. People can build an inter-enterprise application system by integrating web services provided by different enterprises. The resulting application system is composed of loosely coupled, autonomous systems and normally involves long running business process lasting for several hours or several days. To ensure consistent outcome generated by such business process, transactional support is needed.To ensure consistency when concurrent transactions are executed, traditional transaction model requires resources accessed are locked until transaction is committed. This is unsuitable to long-lived transaction because locking resources for a long time leads to an unacceptable system performance. Existing long-lived transaction model reduces the time needed to lock resources by decompose global transaction into a series of sub-transactions, which can commit independently. Compensating transaction is used to undo the effects made by committed sub-transactions when global transaction is partially executed. But in web services world, existing transaction management protocol does not provide the implementation of compensating transaction. It requires application developer to implement compensating transaction.In this paper, we proposed a general long-lived transaction management service based on automatically compensating transaction generation according to existing long-lived transaction model. This long-lived transaction management service proposed a coordination algorithm, which permits user to select wanted results from committed sub-transactions. This service uses compensating transaction to undo committed sub-transaction which user does not want. Compensating transaction is generated by this service when sub-transaction is being executed. This service is deployed independently as a web service and does not require existing web services to change their implementation.In this paper, we discuss the requirement of the long-lived transaction management service and the implementation way of coordination algorithm and automatically compensating transaction generation by using trigger. Then we design and implement this service. At last we design test cases by discussing the requirement of test long-lived transaction management service and validates the correctness of implementation of this service by executing those test cases.