A Research On Some Key Technologies Of Exception Handling For Smart Process

With the rapid development of Information Technology and Internet, information application mode changed extensively while most large scale network system are based on the massive cooperative process of services to achieve business goals, namely business process is everywhere. This paper analyses the characteristics of complex applications in dynamic and open Internet environment and names Internet-based process-oriented complex applications as Smart Process-based Applications, which meet the diverse and personalized requirements of large scale users in Internet environment and provide flexible and open environment for constructing business process to realize business goals based on dynamic service composition through network and software service. Due to the dynamic and open characteristic of Internet itself, exception handing in Smart Process-based Applications becomes more important and hampers the generalization and evolution of smart process-based applications. As the key common backstop technology of many novel applications in future, research on exception handing got a lot of eyes on it and could provide theoretical principle and technical support for the modern application with characteristics of networking and informationization.This paper carried research on the exception handing in Smart Process-based Applications on characteristics of unpredictability, geographical distribution, asynchronism of temporal coordination and self-adapting, presented multi-level exception handing mechanism of smart process, provided business service layer-oriented and business layer-oriented exception handing methods, and constructed the exception handing system with high agility and self-adapting to make Smart Process agile and adaptable to the variational user requirements and complex, diversiform execution environments. The main works include:(1) Study the multilayer exception handing mechanism in smart process execution model. Exceptions may appear with certain dependency across many layers while smart process running in the distributed environment. In business service layer, we study the temporal-restriction management and service execution state transformation and explore the business service layer-oriented exception handing methods; in business layer, we study the relationship between tasks and withdrawal business spanning graph and then explore the business layer-oriented exception handing methods. In addition, we show the principle of the exception handing mechanism of multilayer smart process through the study and design of exception handing architecture for Smart Process-based Applications.(2) Study the user satisfaction evaluation and semantics constraint validation after exception handing of smart process. We present the evaluation of user satisfaction through cost, temporal, functionality and reliability facets of exception handing results. In addition, we make a research on the semantics constraints of smart process and verify the semantics validation of smart process after exception handing to avoid the semantics errors and rule violation.(3) Study the exception handing pattern and operations in Smart Process-based Applications. Pattern is used to solve the repeated similar problems, which could be used in exception handing though the exceptions occurs unpredictable. We classified the exception handing methods through pattern and studied the basic operations of pattern management as an automatic technique method for exception handing.(4) Do the emulation experiments of exception handing in Smart Process-based Applications. Verify the validation and rationality of exception handing methods through emulation and make the user satisfaction evaluation in the exception handing results.The main contributions are as follows:(1) We propose a multilayer exception handing mechanism of Smart Process-based Applications.We study the exception handing of Smart Process-based Applications through many layers, which study the exception handing methods in an individual layer and furthermore consider the impacts of exception handing to other layers, and construct a multilayer exception handing mechanism through coordination between different layers. The extended smart process execution model based on exception handing mechanism not only designs the intact exception handing methods to business service layer, business layer and other layers, but also provides coordinations between different exception handing methods. Furthermore, we evaluate the user satisfaction and verify the semantics validation after exception handing. Then we could build exception handing system with agility and self-adaptability, and achieve goals such as meeting user requirements swiftly, self-adaptability to diverse execution environments and so on.(2) We present an exception handling method with business service execution state transition based on temporal constraint management.We explore the impact of temporal constraints with relaxation on smart process execution based on temporal constraints management of business service, and introduce some concepts such as goal to describe the execution state of business service in smart process. Based on the service execution state transformation graph, we present an exception handing method with relaxing temporal constraints. With this method, business service could select the rational execution state for transformation in order to the temporal constraints related problem while smart process is running.(3) We presented an exception handling method based on service withdrawal orienting business layer.We explore the many states of tasks and withdrawal dependencies among tasks in business layer, define the withdrawal dependency based on logical model of smart process execution, and build the withdrawal business spanning graph according to the withdrawal dependency between tasks of smart process. This method could satisfy the demand of dynamic adaptation and re-construction using withdrawal business service when exception occurs. In addition, we propose a service transfer model to achieve the same result of withdrawal service through encapsulating, publishing and transferring business service. Then we could solve the problems like business service withdrawal methods don't exist or withdrawal cost is too high, and improve the ability of automation and self-adaptability in exception handing in smart process.Through the study of multi-level exception handing in Smart Process-based Applications, state transformation of service execution, business withdrawal spanning graph, user satisfaction of exception handing results and validation of semantics constraints, we build the smart process exception handling architecture, and present some key technologies and algorithms for exception handing. The research enriches and consummates the theoretical foundations, and promotes Smart Process-based Applications.