XDFT: An Extensible Dynamic Fault Tolerance Mechanism For Cooperative Plotting System

For the working characteristics of information society such as interoperability, distributing, collaboration, computer supported cooperative work becomes more and more important and cooperative plotting system is its application in plotting field.According to the requirement of high-availability, real-time and high performance in cooperative system, an extensible dynamic fault tolerance mechanism (xDFT) is proposed in the paper. The mechanism combines fault tolerance supporting architecture and fault tolerance method: Firstly, an extensible dynamic fault tolerance supporting architecture is defined; then a fault tolerance algorithm, based on the fault tolerance supporting architecture, is proposed. xDFT mechanism dynamically can set load quality of server node with variability of system load to change server redundancy. Service nodes and fault tolerance nodes are allowed to scale dynamically according to the current setting and status of system. It not only improves the service efficiency, but also implements load balancing in a more efficient and simply way.The Cooperative Geographic Information plotting System (CoGIS), developed by Cluster and Grid Computing Lab (CGCL) of Huazhong University of Science and Technology (HUST), adopts xDFT mechanism. CoGIS not only avoids the possibility that the server becomes bottleneck and the problem of single point failure, but also saves the system resource and avoids the waste of the resource of redundant nodes, and provides computer supported cooperative work environment a reliable, high performance service.Finally, the testing results shows the extensible dynamic fault tolerance mechanism xDFT, which makes users acquire continuous,"non-stop"service, can promote reliability and performance for cooperative system and has good practicability.