Remote Direct Memory Access (RDMA) is becoming widely available in data
centers. This technology allows a process to directly read and write the memory
of a remote host, with a mechanism to control access permissions. In this
paper, we study the fundamental power of these capabilities. We consider the
well-known problem of achieving consensus despite failures, and find that RDMA
can improve the inherent trade-off in distributed computing between failure
resilience and performance. Specifically, we show that RDMA allows algorithms
that simultaneously achieve high resilience and high performance, while
traditional algorithms had to choose one or another. With Byzantine failures,
we give an algorithm that only requires $n \geq 2f_P + 1$ processes (where
$f_P$ is the maximum number of faulty processes) and decides in two (network)
delays in common executions. With crash failures, we give an algorithm that
only requires $n \geq f_P + 1$ processes and also decides in two delays. Both
algorithms tolerate a minority of memory failures inherent to RDMA, and they
provide safety in asynchronous systems and liveness with standard additional
assumptions.

通过研究远程直接内存访问技术在实现共识方面的应用，本文发现 RDMA 技术可以改善分布式计算中容错和性能之间的固有平衡问题，提出了一些只需要基本的网络延迟就可以实现高容错和高性能的算法。