Research On Some Key Issues In The Lifecycle Of BPEL Processes

Internet has been the infrastructure more and more important in modern age. Web Services based on SOA(Service Oriented Architecture) arise at the historic moment, and they are the best choices implementing SOA. BPEL (Business Process Execution Language) is the de-facto standard among all the web services’ composition languages currently. Correct and effective design, compilation, running and encapsulation of BPEL processes will directly affect the execution efficiency of a corporation’s business processes, thus will indirectly affect the production efficiency of the corporation.This dissertation studies some key issues during five stages in the lifecycle of BPEL processes. These five stages are requirement description stage, compilation stage, static stage, execution stage and encapsulation stage. The solutions to these issues will promote the accuracy and efficiency of BPEL processes. The main research contents are as follows:We research about in BPEL’s requirement description stage, how to automatically generate BPEL processes from natural language described functional requirements. Firstly, requirements description is restricted and formalized; then, those Web Services with the highest semantic compatibility are found in the database of WSDLs; finally, the whole BPEL process is assembled level by level upwards. BPEL’s automatic generation can help users and developers reach a consensus on the requirements as soon as possible, thereby speeding up BPEL processes’development.We research about BPEL activities’recommendation problem in compilation stage. When the developer creates a lot of BPEL processes in a specific domain, the number of atomic Web Services is finite, and there always exists some causality between these services. Mining out the relationships between the atomic services using association rules mining, we can make some recommendation of BPEL activities to developers to improve the accuracy and efficiency of processes’compilation.We research about the problem of control dependency deadlocks in compilation stage. In the procedure of BPEL’s compilation, BPEL activities’ execution sequence and element "link" may introduce in some control dependency deadlocks. By online discovering simple cycles in graph theory, deadlocks are detected real-time during the design of BPEL, thus avoiding the difficulty and complexity of detection after huge design work completes.We research about the problem of process templates’generation in BPEL’s static stage. From the set of BPEL processes in a specific domain or application, we make use of rooted unordered trees’frequent patterns mining to find out all the frequent sub-processes, which can be used as templates recommended to developers to achieve the reuse of BPEL processes.We research about the problem of BPEL’s compatibility in execution stage. When BPEL process is being executed, process and invoked services may be incompatible, including interfaces’incompatibility and behaviors’ deadlocks. We use a method based on UML and typed Pi calculus to detect the compatibility and give a method creating adapters while incompatible.We research about the problem of Web Services’ compatibility when BPEL process is encapsulated as a Web Service. We consider multiple factors altogether, including services interfaces’syntax and semantics, services’ behavior, QoS and users’preference, and use Analytic Hierarchy Process(AHP) in operational research to analyze Web Services’compatibility quantitatively.