Modern data centers are becoming increasingly equipped with RDMA-capable NICs. These devices enable distributed systems to rely on algorithms designed for shared memory. RDMA allows consensus to terminate within a few microsecond in failure-free scenarios, yet, RDMA-optimized algorithms still use expensive two-sided operations in case of failure. In this work, we present a new leader-based consensus algorithm that relies solely on one-sided RDMA verbs. Our algorithm is based on Paxos, it decides in a single one-sided RDMA operation in the common case, and changes leader also in a single one-sided RDMA operation in case of failure. We implement our algorithm in the form of an SMR system named Velos, and we evaluated our system against the state-of-the-art competitor Mu. Compared to Mu, our solution adds a small overhead of approximately 0.6 microseconds in failure-free executions and shines during failover periods during which it is 13 times faster in changing leader.

中文翻译：

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Velos：用于 RDMA 应用程序的单面 Paxos

现代数据中心越来越多地配备支持 RDMA 的 NIC。这些设备使分布式系统能够依赖为共享内存设计的算法。RDMA 允许在无故障情况下在几微秒内终止共识，然而，RDMA 优化算法在发生故障时仍然使用昂贵的双边操作。在这项工作中，我们提出了一种新的基于领导者的共识算法，该算法完全依赖于单方面的 RDMA 动词。我们的算法基于 Paxos，它在常见情况下在单个单侧 RDMA 操作中决定，并在失败的情况下在单个单侧 RDMA 操作中更改领导者。我们以名为 Velos 的 SMR 系统的形式实现我们的算法，并针对最先进的竞争对手 Mu 评估了我们的系统。与 Mu 相比，我们的解决方案增加了大约 0 的小开销。