Petri-nets Based Availability Model of Fault-Tolerant Server System

Fault-Tolerant capacity of the key server will effect integrality and restorability of the data in network system, so in order to increase system´s availability, cluster technique has been adopted widely. In despite of achieving high system availability with cluster technique, it makes system very complexly and availability analysis very difficult. By analyzing redundant server system´s structure and work process, stochastic Petri net method is adopted to model processing cell availability, data memory disc availability and server availability. Integrating above models, cluster system availability model can be obtained.