Differential fault-tolerant average for internally synchronising clocks within distributed environments

摘要

An algorithm which is a modification of the well known fault tolerant average algorithm is proposed. The algorithm, called the differential fault tolerant average (DFTA), bounds the maximum drift rate of correct clocks by the maximum drift rate of correct hardware clocks. In order to limit the maximum error in clock readings, the interval of correct clocks are extended so that the maximum and minimum of the interval are limited by the uncertainties in time message reception. For testing and evaluation purposes, a simulation called SimUTC and its user interface, EvalSys were used. The simulation can be monitored using the user interface developed specifically to be used with the simulation, called EvalSys. The results were compared with that of fault tolerant average algorithm and it is proven that this algorithm performed better.