Analysis of Interval-Based Global State Detection

Abstract

The problem of global state observation is fundamental to distributed systems. All interactions in distributed systems can be analyzed in terms of the building block formed by the pairwise interactions of intervals between two processes. Considering causality-based pairwise interactions by which two intervals at different processes may interact with each other, there are 40 possible orthogonal interactions. This paper examines the problem: “If a global state of interest to an application is specified in terms of the pairwise interaction types between each pair of processes, how can such a global state be detected?” A solution identifies a global state in which the relation specified for each process pair is satisfied. This paper formulates the specific conditions on the exact communication structures to determine which of the intervals being examined at any time may never satisfy the stipulated relation for that pair of processes, and therefore that interval must be deleted.