Time, Clocks, and the Ordering of Events in a Distributed System The concept of one event happening before another in a distributed system is examined, and is shown to define a partial ordering of the events. A distributed algorithm is given for synchronizing a system of logical clocks which can be used to totally order the events. The use of the total ordering is illustrated with a method for solving synchronization problems. The algorithm is then specialized for synchronizing physical clocks, and a bound is derived on how far out of synchrony the clocks can become. CACM July, 1978 Lamport, L. Distributed systems, computer networks, clock synchronization, multiprocess systems 4.32 5.29 CA780706 DH February 7, 1979 4:30 PM 3082 5 3082 3082 5 3082 3082 5 3082 3128 5 3082 2150 6 3082 2376 6 3082 2436 6 3082 2597 6 3082 2865 6 3082 2866 6 3082 2870 6 3082 2912 6 3082 3082 6 3082