Detecting Causal Relationships in Distributed Computations: In Search of the 
Holy Grail 

Distributed Computing, Vol. 7 No. 3, pp. 149-174, 1994 

The paper shows that characterizing the causal relationship between 
significant events is an important but non-trivial aspect for understanding 
the behavior of distributed programs. An introduction to the notion of 
causality and its relation to logical time is given; some fundamental results 
concerning the characterization of causality are presented. Recent work on the 
detection of causal relationships in distributed computations is surveyed. The 
relative merits and limitations of the different approaches are discussed, and 
their general feasibility is analyzed.