Distributed Predicate Detection in a Faulty Environment

There has been very little research in distributed predicate detection for faulty, asynchronous environments. In this paper we deene a class of predicates called set decreasing predicates which can be detected in such an environment. We introduce a set of failure detectors called innnitely often accurate detectors which are implementable in asynchronous systems. Based on these failure detectors we present an algorithm to detect conjunction of local predicates and send-monotonic channel predicates. Since perfect failure detection is impossible in an asynchronous system, we cannot guarantee that our detection algorithm will not have false detections. However, if the predicate ever holds then it is guaranteed to be detected.