Research On Service Composition In SaaS Application

With the development of the Internet and WEB2.0 technology, SaaS (Software as a Service) has generally been accepted as main way of the software service delivery. With the development of enterprise business level as well as the expanding of business scope, the demands of SaaS offerings have been rapidly raised. However, the SaaS applications are isolated, which could not follow the rapid change of the business logic.In this paper, we propose an approach to solve this problem by integrating SaaS service together. Based on the architecture for integration we proposed, developers can easily combine the SaaS offerings together based on the dynamic business process in order to meet the user's requirements.To carry out the SaaS service integration, we first analyze the business flow and IT resource available based on two general cases, SBM and APO. Then we give the SaaS service integration architecture and solve several critical problems in the presentation layers, function layer and data layer. First, a new mash-up model is proposed to carry out integration in the presentation layer. Second, we extend the SCA (Service COMPONENT Architecture) to deal with the problems in the service connection and service flow composition. Third, based on the analysis of the service coordination and transaction management mechanism in the Apache Kandula Project, we propose a service coordination model in this paper based on message notification mechanism. Fourth, in order a technology about service authentication and authorization was put forward to tackle the authentication and authorization issues. Last, we adopt the WEB 2.0 techniques, which improve the system efficiency and make the integration loose coupled. We also give a detailed introduction to the integrated SaaS service deployment environment and publication method.Based on our method, we implemented the supporting system and put it into real practice in a large-scale car manufacturing factory in china. The factory demonstrated improvement in both social benefit and economic benefit after the application of our system.