The Performance Analysis Of The Web Services Composition Based On Colored Time Petri Net

Along with the wide application of Web services composition, the performance ismore and more being focused. Through the analysis of the Web services compositionperformance, we can find out the performance defects and satisfy user’s Qosrequirements. so it is necessary to analyze the performance of the servicecomposition.Due to the state space explosion, the performance model proposed recently ishard to analyze the performance of complex Web services composition. In this thesis,the paper proposes a colored timed Petri net(CTPN) to model and anayze the Webservices composition which descricbed by BPEL. CTPN is a kind of graphicalmodeling tool which have an advantage in the description of the system parallel,branch, synchronization, etc; it also introduces the concepts of time and color, whichcan effectively control the problem of the state space explosive.The work of this paper mainly focus on the transformation of BPEL to CPTNmodel and the performance analysis of the Web services composition used byCPN-Tools. The following is the main contributions.1. The paper give a mapping method from the atomic activity and structuredactivity to CTPN model, which realize the transformation from BPEL to CTPNmodel.2. According to the transition rules we convert the Web services compositionwhich described by BPEL to the CPTN model, and use the simulationtools(CPN-Tools) analysing the performance. Firstly，it use the state space Tools toanalyse the CTPN model, and produce the standard state space report, the reportproves the CTPN model is activated and boundedness.Secondly, we use the minitor tocollecte experimental data of queuing time and response time, and analyze the changetrend with the performance indexes in changing to the customer service time intervalsand service time. Thus, we give the performance optimization method.