Timestamping messages in synchronous computations

Abstract

We present a method of timestamping messages and events in synchronous computations that capture the order relationship with vectors of size less than or equal to the size of the vertex cover of the communication topology of the system. Our method is fundamentally different from the techniques of Fidge (1989) and Mattern (1989). The timestamps in our method do not use one component per process but still guarantee that the order relationship is captured accurately. Our algorithm is online and only requires piggybacking of timestamps on program messages. It is applicable to all programs that either use programming languages based on synchronous communication such as CSP or use synchronous remote procedure calls.