Web service composition using markov decision processes

Abstract

This paper discusses a method for dynamic web service composition, which is based on Markov Decision Processes (MDP). It is defined on the base of QoS description and addresses the issue of selecting web services for the purpose of their composition. Web service composition patterns including sequential, conditional, parallel and iterative are modeled in MDP. Two computation algorithms for MDP are introduced and implemented. One is backward recursive iteration and the other is forward iteration, both called Value Iteration. Experiments are conducted to evaluate the performance of MDP methods for service composition. Experimental results show that the methods are efficient. The effect of average failure probability of service invocation on performance is also examined in this paper. © Springer-Verlag Berlin Heidelberg 2005.