About logical clocks for distributed systems

Abstract

Memory space and processor time are basic resources when executing a program. But beside this implementation aspect (this time resource is necessary but does not belong to the program semantics), the concept of time presents a more fundamental facet in distributed systems namely causality relation between events. Put forward by Lamport in 1978, the logical nature of time is of primary importance when designing or analyzing distributed systems. This paper reviews three ways (linear time, vector time and matrix time) which have been proposed to capture causality between events of a distributed computation and which consequently allow to define logical time.