ShiftLock: Mitigate One-sided RDMA Lock Contention via Handover

Explore a 15-minute conference talk from FAST '25 that presents ShiftLock, an innovative solution for mitigating one-sided RDMA lock contention through handover mechanisms. This Distinguished Artifact Award-winning presentation by researchers from Tsinghua University addresses a critical challenge in distributed storage systems that use Remote Direct Memory Access (RDMA) networks. Learn how existing RDMA locks suffer under high contention due to failed lock acquisition attempts and excessive retries, which increase latency and decrease overall system performance. Discover how ShiftLock implements a non-blocking direct client-to-client coordination mechanism inspired by MCS locks, allowing clients to hand over locks directly rather than competing for them. The talk details how this approach achieves CPU efficiency, scalability, and fault tolerance through careful software design and strategic use of RDMA features. The presented protocol supports reader-writer semantics and starvation-freedom while delivering impressive performance improvements—up to 3.62× better goodput, 76.6% reduction in tail latencies in microbenchmarks, and up to 2.85× improvement in transaction goodput compared to existing solutions.