On Making Generalized Paxos Practical

Generalized Paxos (GPaxos) is a recent solution to Generalized Consensus, a distributed problem to which several key agreement problems reduce. We envision that GPaxos may unify within a single and novel Agreement-as-a-Service infrastructure multiple distributed protocols. To date this potential is however not fully unleashed, due to the steep learning curve of the protocol and the high complexity of its implementation. Moreover, before GPaxos reaches a real world usage, several computationally expensive operations have to be optimized and simplified. This paper aims at closing this gap between theory and practice. To this end, we first provide a concise tour of Generalized Paxos, hardly found elsewhere. Then, we assess the versatility of the Generalized Consensus problem by presenting a variation of GPaxos that solves the lease coordination problem. Our last contribution consists in three optimizations that apply to the critical phases of the algorithm: (i) a method to quickly start a new round, (ii) a novel approach to execute a checkpoint, and (iii) a data structure that speeds-up the detection of an agreement.