QoS Based Web Services Composition using Ant Colony Optimization: Mobile Agent Approach

Abstract: Web Services are based on distributed technology and provide standard means of interoperating between different software applications across and within organizational boundaries with the use of XML. Web Services technologies allow interaction between applications. Sometimes a single service given alone does not meet user’s needs. In this case, it is necessary to compose several services in order to achieve the user’s goal. In web service composition, a repository of services is given in which input and output parameters of each service are annotated with a concept from ontology. Given request is defined by a set of known input concepts and a set of wanted output concepts. Semantic composer should find a sequence of services, called composition that satisfies the wanted output concept. In this paper, a semantic composer based on ant colony optimization method is proposed. The proposed composer can find optimal composition length in each challenge set in a reasonable time. The result of the suggested composition can be compare with the best result reported in Web service consortium (WSC).
The novelty of this work lies with our multi-objective optimal-path selection modelling for QoS-based dynamic web service composition and a new version of ACO algorithm that is proposed to solve this multi-objective optimization problem.

Keywords: Web Service, Web Service Composition, Quality of Service, Multi-Agent System, Service-oriented architecture, Multi Objective Ant Colony Optimization