Flexible Paxos: Quorum Intersection Revisited
Flexible Paxos: Quorum Intersection Revisited
复制标题
灵活的 Paxos：重新审视 Quorum 交叉点
DOI：
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发表时间：
2016
期刊：
影响因子：
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通讯作者：
A. Spiegelman
中科院分区：
文献类型：
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作者：
H. Howard;D. Malkhi;A. Spiegelman
分布式共识是现代分布式系统不可或缺的组成部分。被广泛采用的Paxos算法使用两个阶段，每个阶段都需要获得多数人的同意，以可靠地达成共识。在这篇文章中，我们证明了Paxos是保守的，它是许多生产系统的基础。具体地说，我们观察到Paxos的每个阶段可以使用不相交的法定人数。多数法定人数不是必需的，因为相交只需要跨阶段。
利用对原始公式中要求的这种弱化，我们提出了灵活的Paxos，它在Paxos算法的基础上进行了推广，以提供灵活的仲裁。我们证明了灵活的Paxos是安全、高效和易于在现有的分布式系统中使用的。最后，我们讨论了这一结果的广泛影响。例如，通过在接受者数量为偶数时将第二阶段法定人数的大小减少一以及利用小的不相交的第二阶段法定人数来加速稳定状态来提高可用性。
Distributed consensus is integral to modern distributed systems. The widely adopted Paxos algorithm uses two phases, each requiring majority agreement, to reliably reach consensus. In this paper, we demonstrate that Paxos, which lies at the foundation of many production systems, is conservative. Specifically, we observe that each of the phases of Paxos may use non-intersecting quorums. Majority quorums are not necessary as intersection is required only across phases.
Using this weakening of the requirements made in the original formulation, we propose Flexible Paxos, which generalizes over the Paxos algorithm to provide flexible quorums. We show that Flexible Paxos is safe, efficient and easy to utilize in existing distributed systems. We conclude by discussing the wide reaching implications of this result. Examples include improved availability from reducing the size of second phase quorums by one when the number of acceptors is even and utilizing small disjoint phase-2 quorums to speed up the steady-state.