Generalized Paxos Made Byzantine (and Less Complex)

TL;DR

This paper simplifies the understanding of Generalized Paxos and extends it to tolerate Byzantine faults, addressing implementation complexity and enhancing fault tolerance in distributed consensus.

Contribution

It provides a clearer description of Generalized Paxos and introduces a Byzantine fault-tolerant version, making the protocol more accessible and robust.

Findings

Simplified description and pseudocode for Generalized Paxos

Extended protocol to Byzantine fault model

Enhanced understanding and implementation feasibility

Abstract

One of the most recent members of the Paxos family of protocols is Generalized Paxos. This variant of Paxos has the characteristic that it departs from the original specification of consensus, allowing for a weaker safety condition where different processes can have a different views on a sequence being agreed upon. However, much like the original Paxos counterpart, Generalized Paxos does not have a simple implementation. Furthermore, with the recent practical adoption of Byzantine fault tolerant protocols, it is timely and important to understand how Generalized Paxos can be implemented in the Byzantine model. In this paper, we make two main contributions. First, we provide a description of Generalized Paxos that is easier to understand, based on a simpler specification and the pseudocode for a solution that can be readily implemented. Second, we extend the protocol to the Byzantine fault model.