垂直原子广播与被动复制（扩展版）
Vertical Atomic Broadcast and Passive Replication (Extended Version)
AI总结：
本文研究可重构原子广播的实现问题，给出其完整安全与活性规范，提出借助辅助服务的Vertical Atomic Broadcast协议，可在重构时继续处理消息以减少停机时间，且该优势在适配被动复制的更强原子广播版本时仍能保持。
摘要：
原子广播是一种可靠的通信抽象，确保所有进程以统一的全局顺序传递相同的消息集合。它是使用主动复制（又称状态机复制）或被动复制（又称主备复制）实现容错服务的基础构件。我们研究可重构原子广播的实现问题，该抽象进一步允许用户动态调整参与进程的集合，例如应对故障或负载变化。我们给出了该通信抽象的完整安全性与活性规范，并提出了一种实现它的新协议——Vertical Atomic Broadcast（垂直原子广播），该协议借助一个辅助服务来推进重构。与已有方案不同，我们的协议在从正常运行的配置进行重构时，允许系统在就下一个配置达成共识的过程中继续处理消息，从而大幅缩短了系统停机时间。此外我们证明，即便修改协议以支持被动复制所需的更强版本原子广播，这一优势依然能够保持。
英文摘要：
Atomic broadcast is a reliable communication abstraction ensuring that all processes deliver the same set of messages in a common global order. It is a fundamental building block for implementing fault-tolerant services using either active (aka state-machine) or passive (aka primary-backup) replication. We consider the problem of implementing reconfigurable atomic broadcast, which further allows users to dynamically alter the set of participating processes, e.g., in response to failures or changes in the load. We give a complete safety and liveness specification of this communication abstraction and propose a new protocol implementing it, called Vertical Atomic Broadcast, which uses an auxiliary service to facilitate reconfiguration. In contrast to prior proposals, our protocol significantly reduces system downtime when reconfiguring from a functional configuration by allowing it to continue processing messages while agreement on the next configuration is in progress. Furthermore, we show that this advantage can be maintained even when our protocol is modified to support a stronger variant of atomic broadcast required for passive replication.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
