Research On Key Techonlogies Of Policy-Driven Exception Handling For BPEL Processes

WS-BPEL-based service-oriented software development method has been becoming the mainstream of software development methodology.BPEL process,characterized of its dynamic and open-ending operating environment,the distributing and autonomy Web services,as well as loosely coupled structures,has to confront serious challenges to ensure the reliability of BPEL process.Exception handling,as the primary fault-tolerance mechanism,has been widely studied and applied to the various fields.Aiming to improving the exception-handling capacity of BPEL process,this paper explores a policy-driven exception handling method for BPEL processes.We propose a policy-based exception handling description language EHPDL-P,and introduce Colored Petri Net to express the semantic of EHPDL-P,which provides the formal method for the analysis of policy-based exception handling process models.Finally,we design a framework to support the implementation mechanism of exception handling process based on EHPDL-P.This major work includes the following four aspects:1)Proposed a policy-based exception handling description language EHPDL-P.EHPDL-P defines exception classification,exception handling actions,exception handling strategies and rules to model the exception handling strategy for BPEL processes.Based on this language,developers can design exception handling logic in a higher level of abstraction.2)Based on Colored Petri network theory,we establish the formal semantic model of EHPDL-P,which provides the formal method for the analysis of policy-based exception handling process.In this paper,we especially focus on the analysis and resolve of the conflicts among the multiple policies applied for the same type of exception.3)Designed a framework to support the implementation mechanism of exception handling process based on EHPDL-P.We present the key techniques for implement the conversion and execution of strategy.4)Through a case study from the domain of Manufacturing Execution System,this paper demonstrates how to model the exceptions occurring in the vehicle production assemble line.