Random Distributed Algorithms For Clock Synchronization

Abstract

This paper proposes clock synchronization algorithms based on the idea in which randomly chosen m out of the total N processors cooperate to perform the clock adjustment of all processors in a distributed system. Selection of m processors is performed in a fully distributed way. Two types of algorithm which include different random mechanisms of processor selection are described. In the first algorithm, all processors adjust their clocks to the average of received clock signals issued by randomly chosen m processors. In the second algorithm, each processor chooses m processors randomly at its own will and adjust its own clock to the average of the chosen processor clocks. Fault tolerance against processor or link failure is taken into account in both algorithms. These algorithms exhibit desirable features in practical sense like simplicity in implementation, a small number of message exchanged, etc., so that the algorithms can be applied to sufficiently large system. Transient and steady state performances of the proposed algorithms are verified through simulation.