RDMP-KV: Designing Remote Direct Memory Persistence based Key-Value Stores with PMEM

Byte-addressable persistent memory (PMEM) can be directly manipulated by Remote Direct Memory Access (RDMA) capable networks. However, existing studies to combine RDMA and PMEM can not deliver the desired performance due to their PMEM-oblivious communication protocols. In this paper, we propose novel PMEM-aware RDMA-based communication protocols for persistent key-value stores, referred to as Remote Direct Memory Persistence based Key-Value stores (RDMPKV). RDMP-KV employs a hybrid `server-reply/server-bypass' approach to `durably' store individual key-value objects on PMEM-equipped servers. RDMP-KV's runtime can easily adapt to existing (server-assisted durability) and emerging (appliance durability) RDMA-capable interconnects, while ensuring server scalability through a lightweight consistency scheme. Performance evaluations show that RDMP-KV can improve the server-side performance with different persistent key-value storage architectures by up to 22x, as compared with PMEM-oblivious RDMA-`Server-Reply' protocols. Our evaluations also show that RDMP-KV outperforms a distributed PMEM-based filesystem by up to 65% and a recent RDMA-to-PMEM framework by up to 71%.