This paper presents a timed coloured Petri nets based programming tool that supports modeling and performance analysis of distributed World Wide Web environments. A distributed Internet system model, initially described in compliance with queueing theory (QT) rules, is mapped onto the Timed coloured petri net (TCPN) structure by means of queueing system templates. Then, it is executed and analyzed using design/CPN toolset. The proposed distributed Internet systems modeling and design methodology has been applied for evaluation of several system architectures under different external loads.

An extension of HTCPNs-based software tool for Internet systems modelling and evaluation has been proposed in the paper. After the extension the tool provides new possibilities for modelling and analysis of dynamic cluster reconfiguration algorithm. Some implementation details of the algorithm has been presented. The algorithm has been preliminary assessed by simulation.