Verification And Reduction Of Web Service Composition Based On Petri-Net

Web Services offer a new paradigm for distributed computing on the World Wide Web. Web services composition allows us to combine a number of existing Web services into a new, value-added Web service. Mission critical Web services have little tolerance for run time errors, as repairing them at service operation time is usually costly. The development of such Web services requires thorough verification at the design stage in order to detect and correct errors as early as possible.Moreover,lots of web services compositions may have redundant flow designs which can lead to low performance.Then reduction is needed.This thesis proposes a Petri-Net-based verification and redunction approach for Web services composition. The approach consists of three steps involve modeling,verification and reduction. At first, utilizing Petri-Net to model Web services composition with workflow patterns. Then, combining safeness,reachability and liveness to define a Web services composition structure correctness validation model for validate Web services composition. Finally, utilizing flow simplified rules to reduce Web services composition.About the implementation of this approach, the thesis achieves Petri-Net modeling of Web services composition by a series transforms between BPEL document and PNML document. Then, verify three Petri Net properties of PNML document showed above by Coverability Tree,Incidence Matrix and State Equation,Transitive Matrix analysis method respectively. Finally, utilizing Web services composition algebraic...