Stabilizing Consensus with the Power of Two Choices
Consensus problems occur in many contexts and have therefore been intensively studied in the past. In the standard consensus problem there are n processes with possibly different input values and the goal is to eventually reach a point at which all processes commit to exactly one of these values. We are studying a slight variant of the consensus problem called the stabilizing consensus problem. In this problem, we do not require that each process commits to a final value at some point, but that eventually they arrive at a common value without necessarily being aware of that. This should work irrespective of the states in which the processes are starting. Coming up with a self-stabilizing rule is easy without adversarial involvement, but we allow some T-bounded adversary to manipulate any T processes at any time. In this situation, a perfect consensus is impossible to reach, so we only require that there is a time point t and value v so that at any point after t, all but up to O(T) processes agree on v, which we call an almost stable consensus. As we will demonstrate, there is a surprisingly simple rule for the standard message passing model that just needs O(log n loglog n) time for any sqrt{n}-bounded adversary and just O(log n) time without adversarial involvement, with high probability, to reach an (almost) stable consensus from any initial state. A stable consensus is reached, with high probability, in the absence of adversarial involvement.
Distributed consensus
1-21
Regular Paper
Benjamin
Doerr
Benjamin Doerr
Leslie Ann
Goldberg
Leslie Ann Goldberg
Lorenz
Minder
Lorenz Minder
Thomas
Sauerwald
Thomas Sauerwald
Christian
Scheideler
Christian Scheideler
10.4230/DagSemProc.09371.6
Creative Commons Attribution 4.0 International license
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