Research On Dynamic Optimization Mechanism Of BPEL-Based Service Composition

The research subject of this thesis comes from the topic "The Architecture Systemof Application Software for the Survey&Design Enterprise Based on SOATechnology", which is one sub-topic of the topic "Research and Application for KeyTechnology of the Survey&Design Enterprise Infomationization", which is one of theKey Projects in the National Science&Technology Pillar Program during the EleventhFive-Year Plan Period.With the growth of the global enterprise collaboration, service composition isbecoming more and more important. For BPEL, because of its simple implementationand powerful function, has been accepted by more and more corporate users. However,with the increasing number of Web service with similar functions in the Internet, serviceselection has become increasingly difficult. Meanwhile, the existing Web serviceprocess is complicated, some business process is difficult to be finalized in the step ofthe definition. Therefore, BPEL-based service composition should have abilities of gooddynamic service selection and deciding the execution order of business processaccording to the actual environment.In the research on BPEL-based service composition optimization, the businessprocess was based on the service’s QoS during the service selection, moreover, thebusiness process considered the intrinsic relationship between the service during theservice execution order optimization. Therefore, during the service selection, the paperimproved the traditional branch and bound method, designed the algorithm of QoSglobal optimization, and realized the dynamic service selection based on QoS globaloptimization under meeting the constraints, meanwhile, in the process of the serviceexecution order optimization, the paper was based on the cost between Web service andimproved the existing IPGA algorithm based on the partheno-genetic algorithm, andminimised the execution cost.This paper mainly accomplished the following tasks:①Analyzed a variety of service composition, focusing on service compositionbased on BPEL, and proposed the paper’s research direction and meaning.②Combined with the research background, analyzed the existing optimizationmethods of BPEL-based service composition, and summarized their weak points, thenproposed two optimization aspects: service selection and service execution order of the process.③Proposed the service selection algorithm with QoS global optimization based onthe improved branch and bound method, reduced the complexity of building thesolution space tree and improved the efficiency of the traditional branch and boundmethod through using the advantages of the matrix.④Translated the service execution order optimization into the TSP problem,proposed the optimization algorithm of service execution order and overcame theIPGA’s weak points of the bad global convergence and low efficiency.⑤A dynamic optimization mechanism for service composition in BPEL based onoptimization algorithm was proposed. On the basis of the existing agent-based BPELservice composition model, two optimization modules based on the optimizationalgorithm were added to the service agent, and finally the mechanism was designed.⑥The simulation and experimental analysis showed the feasibility of themechanism and the performance of the algorithm.