Synchronizing clocks in the presence of faults
Journal of the ACM (JACM)
Synchronization of Fault-Tolerant Clocks in the Presence of Malicious Failures
IEEE Transactions on Computers - Fault-Tolerant Computing
Hardware-Assisted Software Clock Synchronization for Homogeneous Distributed Systems
IEEE Transactions on Computers
Practical uses of synchronized clocks in distributed systems
PODC '91 Proceedings of the tenth annual ACM symposium on Principles of distributed computing
The Byzantine Generals Problem
ACM Transactions on Programming Languages and Systems (TOPLAS)
A new fault-tolerant algorithm for clock synchronization
PODC '84 Proceedings of the third annual ACM symposium on Principles of distributed computing
Understanding Protocols for Byzantine Clock Synchronization
Understanding Protocols for Byzantine Clock Synchronization
Formal Verification of a Fault Tolerant Clock Synchronization Algorithm
Formal Verification of a Fault Tolerant Clock Synchronization Algorithm
On the definition of "on-line" in job scheduling problems
ACM SIGACT News
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The objective of this work is to validate mathematically derived clock synchronization theories and their associated algorithms through experiment. Two theories are considered, the Interactive Convergence Clock Synchronization Algorithm and the Mid-Point Algorithm. Special clock circuitry was designed and built so that several operating conditions and failure modes (including malicious failures) could be tested. Both theories are shown to predict conservative upper bounds (i.e., measured values of clock skew were always less than the theory prediction). Insight gained during experimentation led to alternative derivations of the theories. These new theories accurately predict the clock system's behavior. It is found that a 100% penalty is paid to tolerate worst case failures. It is also shown that under optimal conditions (with minimum error and no failures) the clock skew can be as much as 3 clock ticks. Clock skew grows to 6 clock ticks when failures are present. Finally, it is concluded that one cannot rely solely on test procedures or theoretical analysis to predict worst case conditions.