A Stochastic Timed Performance Model for Web Service Composition

In recently years, the web service composition becomes a new approach of distributed application integration. The time cost of the composed web service is one of the most concerned characters by users. Due to the long delay and uncertainty of the Internet, the performance prediction becomes a difficult problem for the web service composition. A novel performance simulation model, called STPM, is presented in this paper. Based on the stochastic timed Petri net, the STPM model can simulate and predict multiple performance characters, such as the average delay time of the service request, the average length of the service request queue and average response time of the service request etc. To examine the validation of the STMP model for performance simulation of WSC, some simulation experiments have been fulfilled based on the CPN Tools, a modeling and simulation tools based on the hieratical CPN. The experiment results demonstrate the feasibility and efficiency of the STPM model.