Research And Implementation On Web Service Composition-based Transactional Reliability Framework

Web Services technologies bring new network computing mode.Usually application integration in enterprise, because application platform and programming language among enterprises was different, was complex and difficult.It is suitable for Web Services. We can package kinds of applications as Web Services, and then deploy them into intranet/internet, where they can be dynamicly found and integrated,so as to implement the interoperability between platforms and operation systems.As one of the key technologies in the area of web services,transactions determine whether web services can be introduced to enterprises broadly.This paper begins with the tranditional ACID transactions,then analysis the development history of transaction models,and deep into description of the main models of transaction,from flat transaction to extened transactions including nested transaction,open nested trasaction,sagas and so on.We select WS-TX as the base of the framework by analysising and comparing ralative protocols of web services transaction.Based on the analysis of existing protocols,we first advocate that we can put the protocol of web service transaction into business process transaction,so that the business process not only support business transaction,but also support atomic tranction and cross-process transaction.Then we set forth the Web Services Composition-Transaction Reliability Framework.The reseach for transactional reliability comes down to two aspects,the first is the failure recovery of web service composition which is used to maintain the consistensy of transaction.We emphasize particularly on the machanism of failure recovery in atomic transaction,the failure recovery in business transaction is explained simply when needed.At the same time,we put forward the algorithm of coordinator-initiated failure recovery,so as to accommodate web service environment.Then,we point out that some kind of complete dependency and compensate pass can exist because of the lack of isolation in business transaction.And we do deep research by extending coordinator services and participant services in existing protocol so as to provide effective examing means to maintain the consistensy of business transactions.At last,we discuss the realisation of the frame work and evaluate the framework with some examples.