Optimization and Ranking in Web Service Composition using Performance Index

Selection of the best service from the existing composite services is an emerging technology that aims at attaining a better performance. The steps involved include selection of relevant web services from the composite service, followed by optimization and ranking that ultimately leads to the execution of the best service. This paper concentrates on combining optimization and ranking based on non-functional QoS parameters to evaluate its quality. The concept of optimization is carried out by ACO (Ant Colony Optimization) algorithm. The optimization principle uses the concept of pheromone deposition and evaporation on the services. Ranking is done using performance index which is calculated dynamically from the non-functional QoS parameters. This ensures that the application based on this approach is efficient and fault tolerant. The result is obtained by measuring the performance of the services for multiple requests. Keyword- Web service, Optimization and Ranking, Performance Index, Quality of service/composition