Real-time Scheduling Algorithm of Hybrid with Fault-tolerant in Heterogeneous Distributed Systems
Deng Hui-min · 2011
The primary/backup process is commonly used in heterogeneous distributed systems with fault-tolerance.This paper proposed a heterogeneous distributed hybrid model with fault-tolerance.Compared with the traditional hetero-geneous distributed scheduling models,this model can simultaneously schedule both periodical and aperiodical tasks.Three fault-tolerant scheduling algorithms based on this model were presented:SSA(Schedulability Scheduling Algorithm) algorithm aimed at schedulability,RSA(Reliability Scheduling Algorithm) algorithm aimed at reliability and BSA(Balanced Scheduling Algorithm) algorithm aimed at load equalization.These algorithms can simultaneously process real-time tasks in demand of periodical or aperiodical fault-tolerance in heterogeneous systems.And they can guarantee that real-time tasks could complete befor the cut-off time even if some node of the system fails.Finally,this paper analyseds the algorithms in five ways:schedulability,reliability cost,load equalization,number of periodical and aperiodical tasks,cycle and granularity.Experiment results show that the algorithms have advantages and disadvantages respectively,so they should be chosen according to the characteristics of a specail heterogeneous system.