Global Predicate Detection under Fine-Grained Modalities

Predicate detection is an important problem in distributed systems. Based on the temporal interactions of intervals, there exists a rich class of modalities under which global predicates can be specified. For a conjunctive predicate φ, we show how to detect the traditional Possibly(φ) and Definitely(φ) modalities along with the added information of the exact interaction type between each pair of intervals (one interval at each process). The polynomial time, space, and message complexities of the proposed on-line detection algorithms to detect Possibly and Definitely in terms of the fine-grained interaction types per pair of processes, are the same as those of the earlier on-line algorithms that can detect only whether the Possibly and Definitely modalities hold.