Abstract
This paper firstly proposes the architecture for a distributed environment scanning system, which is based upon Multi-Agent. According to the theory of Hierarchical Timed Colored Petri Nets (HTCP-net), a system scheduling model is built with modeling and simulation tools CPN Tools for the priority-based task scheduling algorithm and shortest waiting queue dynamic load balance scheduling algorithm. Finally, the model executes for simulation, and demonstrates average waiting time of tasks and average length of each agent waiting queue. Compared with the results from simulation of cyclic scheduling algorithm, it meets the system demands of periodically repeated web page visit.