Timed Colored Petri Net-Based Event Generators for Web Systems Simulation

Simulation is a powerful process for perfectly planning and dimensioning web systems. However, a successful analysis using a simulation model usually requires variable load intensities. Furthermore, as the client’s behavior is subject to frequent changes in modern web systems, such models need to be adapted as well. Based on web systems observation, we come across the need for tools that allow flexible definitions of web systems load profiles. We propose Timed Colored Petri Nets (TCPN) event generators for web environments that could be used to drive simulations for performance evaluation. The article proposes the systematization of the generators for future development. The theoretical part focuses on a classification with a division into deterministic/stochastic and untimed/timed generators. Next, in this study, we investigate representative models of generators from different classes based on the formalism of TCPN. We perform model design and simulation processes using CPN Tools software. Finally, we present a case study involving workload analysis of a web system that processes requests from the designed generator.