The Research And Realization Of Web Services Transaction Middleware Support QoS

To ensure the credible of Web services, it need web service transaction. Some technology of convention transaction and experience is used for reference by academe and industry to propose specification of transaction for web services, so as to solve the problem of the transaction for web services .However, the specification is not so much perfect, for there is much difference between traditional transaction and web services transaction, and some new problems appear, it can' t solve the problems in application of web services transaction. So still lots of things should be studied .In this paper, the model and specification of transaction were discussed, based on the traditional transaction and web service transaction. We found that Tight Coupling existed in each participant of transaction, which is disobey the principle of Loose Coupling. So we presented architecture of decoupled web service transaction middleware, and realized it. Our work include several aspect bellows:1) Designed the architecture of the web service transaction middleware ; decoupled each part of web service transaction (such as application program ,coordination and service provider), so decoupled the application program and coordination, and improved the universality of coordination , made it appears independently as a third part software , to be a web services transaction middleware . Every module of transaction middleware were published to web service .So our system get better flexibility and expandability.2) On the basis of the transaction middleware model, we proposed the QoS manager . We have designed QoS attributes of web services definition. According to the service provider' s QoS preference to service invoker, we present a way to standard the value of QoS attribute and the computing model for the synthetic evaluation for QoS , embody autonomy of service provider and ensure its benifit. In this paper , we used layer analysis method, that can automate correcting the judge matrix which is not satisfy the consistency, to compute the weight of QoS attribute , so as to make the transaction process to ensure the automaticity and continuity .3) We have designed and implemented Web Services atomic transaction model and coordination protocol. Extended the coordination specification for web services business activity, study the compensation of the business activity, and choose the way of compensate action by config file.