Fast and general distributed transactions using RDMA and HTM.

Recent transaction processing systems attempt to leverage advanced hardware features like RDMA and HTM to significantly boost performance, which, however, pose several limitations like requiring priori knowledge of read/write sets of transactions and providing no availability support. In this paper, we present DrTM+R, a fast in-memory transaction processing system that retains the performance benefit from advanced hardware features, while supporting general transactional workloads and high availability through replication. DrTM+R addresses the generality issue by designing a hybrid OCC and locking scheme, which leverages the strong atomicity of HTM and the strong consistency of RDMA to preserve strict serializability with high performance. To resolve the race condition between the immediate visibility of records updated by HTM transactions and the unready replication of such records, DrTM+R leverages an optimistic replication scheme that uses seqlock-like versioning to distinguish the visibility of tuples and the readiness of record replication. Evaluation using typical OLTP workloads like TPC-C and SmallBank shows that DrTM+R scales well on a 6-node cluster and achieves over 5.69 and 94 million transactions per second without replication for TPC-C and SmallBank respectively. Enabling 3-way replication on DrTM+R only incurs at most 41% overhead before reaching network bottleneck, and is still an order-of-magnitude faster than a state-of-the-art distributed transaction system (Calvin).