Title :
An algorithm for fault-tolerant clock state & rate synchronization
Author :
Schossmaier, Klaus ; Weiss, Bettina
Author_Institution :
Dept. of Autom., Tech. Univ. Wien, Austria
Abstract :
We propose a fault-tolerant algorithm for synchronizing both state and rate of clocks in a distributed system. This algorithm is based on rounds, uses our fault-tolerant optimal precision (OF) convergence function as the means of synchronization, and maintains a collection of intervals to keep track of real-time, internal global time, and clock rates. The analysis shows that the interlocking between state and rate synchronization can be easily solved, and that oscillator stabilities together with the transmission delay uncertainties of packets predominate the internal synchronization. In addition, average case results gathered from simulation experiments with our SimUTC toolkit prove to be about one order of magnitude better than the worst case ones from the analysis of our state & rate algorithm
Keywords :
clocks; delays; distributed processing; real-time systems; software fault tolerance; synchronisation; SimUTC toolkit; clock rate synchronization; clock rates; clock state synchronization; distributed system; fault-tolerant algorithm; internal global time; optimal precision convergence function; oscillator stabilities; real-time system; transmission delay uncertainties; Analytical models; Clocks; Convergence; Delay; Fault tolerance; Fault tolerant systems; Oscillators; Stability analysis; Synchronization; Uncertainty;
Conference_Titel :
Reliable Distributed Systems, 1999. Proceedings of the 18th IEEE Symposium on
Conference_Location :
Lausanne
Print_ISBN :
0-7695-0290-3
DOI :
10.1109/RELDIS.1999.805081