Online applications now routinely replicate their data at multiple sites around the world. In this paper we present Atlas, the first state-machine replication protocol tailored for such planet-scale systems. Atlas does not rely on a distinguished leader, so clients enjoy the same quality of service independently of their geographical locations. Furthermore, client-perceived latency improves as we add sites closer to clients. To achieve this, Atlas minimizes the size of its quorums using an observation that concurrent data center failures are rare. It also processes a high percentage of accesses in a single round trip, even when these conflict. We experimentally demonstrate that Atlas consistently outperforms state-of-the-art protocols in planet-scale scenarios. In particular, Atlas is up to two times faster than Flexible Paxos with identical failure assumptions, and more than doubles the performance of Egalitarian Paxos in the YCSB benchmark.

中文翻译：

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行星规模系统的状态机复制（扩展版）

在线应用程序现在经常在世界各地的多个站点复制其数据。在本文中，我们介绍了 Atlas，这是第一个为此类行星规模系统量身定制的状态机复制协议。Atlas 不依赖于杰出的领导者，因此客户可以不受地理位置的影响而享受相同的服务质量。此外，随着我​​们添加离客户端更近的站点，客户端感知的延迟会得到改善。为了实现这一目标，Atlas 使用并发数据中心故障很少见的观察来最小化其仲裁的大小。它还在单次往返中处理高百分比的访问，即使这些访问发生冲突。我们通过实验证明，Atlas 在全球范围内始终优于最先进的协议。特别是，