LinKV: An RDMA-Enabled KVS for High Performance and Strict Consistency Under Skew

We present LinKV, a novel distributed key-value store that can leverage RDMA network to simultaneously provide high performance and strict consistency (i.e., per-key linearizability) for skewed workloads. To avoid the potential performance loss caused by load imbalance under skew, existing solutions will replicate popular items into different nodes’ caches to support quick and even accesses. But for those writes hitting cache, there will be multiple consistency actions to guarantee linearizability, which degrade the overall performance. In this paper, we present a batch method to make multiple writes amortize those overheads caused by a round of consistency actions. While for reads, we introduce a lease-based scheme to make them quickly return the most recently completed batches of writes. Comparing to the state-of-the-art solutions, LinKV with above strategies can improve the throughput by 1.5 - 3 × and reduce the latency to about 10 % with different write ratios under skew.