Asynchronous group membership with oracles

Kal Lin and Vassos Hadzilacos

We present a model of distributed systems intended for the description of group membership services. The model incorporates a generalization of failure detectors~\cite{CT96}, which we call oracles. Oracles provide information about processes that may be included into or excluded from the group. Based on this model, we provide a specification of a group membership service in asynchronous systems augmented with oracles. We also present an algorithm that implements such a service provided that the information supplied by the oracles is of sufficient quality.