Existing approaches to tolerate Byzantine faults in geo-replicated environments require systems to execute complex agreement protocols over wide-area links and consequently are often associated with high response times. In this paper we address this problem with Spider, a resilient replication architecture for geo-distributed systems that leverages the availability characteristics of today's public-cloud infrastructures to minimize complexity and reduce latency. Spider models a system as a collection of loosely coupled replica groups whose members are hosted in different cloud-provided fault domains (i.e., availability zones) of the same geographic region. This structural organization makes it possible to achieve low response times by placing replica groups in close proximity to clients while still enabling the replicas of a group to interact over short-distance links. To handle the inter-group communication necessary for strong consistency Spider uses a reliable group-to-group message channel with first-in-first-out semantics and built-in flow control that significantly simplifies system design.

中文翻译：

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具有低延迟的弹性基于云的复制

在地理复制环境中容忍拜占庭故障的现有方法需要系统在广域链接上执行复杂的协议协议，因此通常与高响应时间相关联。在本文中，我们使用 Spider 解决了这个问题，Spider 是一种用于地理分布式系统的弹性复制架构，它利用当今公共云基础架构的可用性特性来最小化复杂性并减少延迟。Spider 将系统建模为一组松散耦合的副本组，这些副本组的成员托管在同一地理区域的不同云提供的故障域（即，可用性区域）中。这种结构性组织可以通过将副本组放置在靠近客户端的位置，同时仍然使组的副本能够通过短距离链接进行交互来实现低响应时间。为了处理强一致性所需的组间通信，Spider 使用可靠的组到组消息通道，具有先进先出语义和内置流控制，可显着简化系统设计。