Research And Practice Of Enterprise Asynchronous Transaction

Transaction is a key service for developing stable application. It's an advanced specification in coding. Key tasks are able to run in a stable enterprise environment with transactions. Transactions have four attributes: atomicity, consistency, isolation and durability. There are two ways to terminate a transaction: commit and rollback.Enterprise transactions sometimes may come down to subsystems of different departments in the current enterprise information systems. Additionally, the transactions need to be completed by coordination of subsystems in a long time. In traditional transactions, the atomicity attribute requires that if a transaction is not finished, all its corresponding tasks that have been done should be aborted, whereas the serial feature of transaction requires that if one transaction is incomplete, all other corresponding transactions should wait. These two traditional parallel transaction control methods can not meet the requirement of enterprise asynchronous transaction management. Asynchronous transactions come into being to meet such requirements. Different from synchronous transactions, asynchronous transactions use unblock mechanism in which caller procedures do not need to wait the caller procedures' results as they do in synchronous environment. Transaction maker starts a transaction and informs all participants. A transaction completes itself only if all the participants finish their tasks. When a transaction needs to rollback if something goes wrong, it can rollback to the initial point according to the enterprise requirements or just rollback some sub-transactions to their initial points in order to restart the transaction.Synchronous transactions often use remote procedure call, RPC to deal with distributed applications. When calling remote methods, transaction maker is in the blocked status before the calling procedure returns. The transaction proceeds after the caller procedure returns successfully. Messaging mechanism can be used instead of RPC. Message Oriented Middleware (MOM) refers to an arbitrary basic architecture that supports message mechanism. In the past few years, MOM has already become a special technique. Each kind of products has its own application interface and their source code can not be transferred to other message mechanisms. Thus, it makes customers to focus on one specific kind of products and can not change in future. Additionally, it can bring bad effects to developers because they have to learn the special interface when using a new messaging product.Java Message Service, JMS provides us with a clear way to deal with enterprise message. It connects an application's different components by using asynchronous message transmitting in process communication. Message system helps to decompose asynchronous transaction into several sub-transactions. It enhances the asynchronous transactions' validity. To this end, when a client starts a transaction and sends the transaction process request message to the message server, the client does not need to wait the responding results to process its proceeding tasks. The messaging system returns the result after it processes the requested message. JMS provides good support for enterprise asynchronous transactions.By using asynchronous transactions, all existing enterprise resources can be integrated. Additionally, it reduces inter-application coupling and realizes loose coupling. Finally, it produces...