The combined power of conditions and failure detectors to solve asynchronous set agreement
Achour Mostéfaoui, Sergio Rajsbaum, Michel Raynal · 2005
An approach to cope with the impossibility of solving agreement problems in asynchronous systems made up of n processes and prone to t process crashes is to use failure detectors. An orthogonal approach that has been used is to consider conditions that restrict the possible inputs to such a problem. This paper considers a system with both failure detectors and conditions. The aim is to identify the failure detector class that abstracts away the synchrony needed to solve k-set agreement for a given condition.Three main contributions are presented. The first is a new class of failure detectors denoted Φty, 0≤ y≤ t. The processes can invoke a primitive queryy(S) with a set of process ids S. Roughly speaking, queryy(S) returns true only when all processes in S have crashed, provided t-y