The Research On Web Service Composition Technology Based On Functional Programming

Service Oriented Computing (SOC) is an emerging distributed computing paradigm which emphasizes on building application with well-defined business services and describing the system behaviors with service composition and collaboration. Such applications have the characteristics of loose-couple, agility and dynamic adaptability. How to form the coarse-granularity business service from the fine-granularity elemental services is one of the vital problems that need to be solved in SOC.This paper focuses on the topic of designing and implementing a functional service composition model. According to the multiple-phases, dynamic and distributed properties of service composition, a functional programming style and Monad based service composition model and language are proposed and designed. Besides, a critical path based service composition optimization algorithm for distributed execution is also provided. All the model, language and algorithm have been implemented in XDWSC (XiDian Web Service Composition). In order to verify the correctness, validity and related performance of this solution, systematic experiment is conducted in this paper.(1) Service oriented computing environment and service composition reference model.Based on the study of enterprise computing framework, a service oriented computing environment independent to the applications is defined. We investigate the the characteristics of service-oriented computing environment and the developing process of composite service. With the common supporting functions for composite service application resolved, the Service Composition Reference Model (SCRM) is proposed. SCRM provides a reference framework for analyzing, modeling, deploying and running of service composition.(2) A functional programming style and Monad based service composition model named Functional Service Composition Model (FSCM).Modern enterprise applications have proposed much higher demand on agility and running concurrency of constructing service compostion system. Based on the comparision results among present service composition methods and SCRM, we propose a functional programming style and Monad based service composition method. Its essence is to describe the composite service by building corresponding FSCM. Composite services based on FSCM are prone to deploy and execute in distributed environment.(3) Functional Service Composition Language (FSCL) and its C++ implementation.We propose a framework of functional service composition based on code generation. In our framework, a FSCL program describing the composition logic is mapped and translated into C++ implementation programs. These programs are compiled and packed to executable modules with the support of service composition class libraries, which can be deployed and executed in our XDComposer system.(4) A critical path based service composition optimization algorithm for distributed execution.Guided by the opinion"Centralized Model, Distributed Execution", we design the restricted Recursive Critical Path (rRCP) algorithm, which splits the centralized composite service model into small pieces executed concurrently in a given distributed execution environment. The distributed execution patterns generated by rRCP shows performance superiority compared to centralized execution fashion.(5) Based on the above studies, we design and implement a service composition platform named XDWSC, which is an important infrastructure of our"Integration Environment for System Design Tools"and"Domain Specific Enterprise Service Bus".