Accelerating Redis with RDMA Over InfiniBand

Abstract

Redis is an open source high-performance in-memory key-value database supporting data persistence. Redis maintains all of the data sets and intermediate results in the main memory, using periodical persistence operations to write data onto the hard disk and guarantee the persistence of data. InfiniBand is usually used in high-performance computing domains because of its very high throughput and very low latency. Using RDMA technology over InfiniBand can efficiently improve network-communication’s performance, increasing throughput and reducing network latency while reducing CPU utilization. In this paper, we propose a novel RDMA based design of Redis, using RDMA technology to accelerate Redis, helping Redis show a superior performance. The optimized Redis not only supports the socket based conventional network communication but also supports RDMA based high-performance network communication. In the high-performance network communication module of optimized Redis, Redis clients write their requests to the Redis server by using RDMA writes over an Unreliable Connection and the Redis server uses RDMA SEND over an Unreliable Datagram to send responses to Redis clients. The performance evaluation of our novel design reveals that when the size of key is fixed at 16 bytes and the size of value is 3 KB, the average latency of SET operations of RDMA based Redis is between 53 µs and 56 µs. This is about two times faster than IPoIB based Redis. And we also present a dynamic Registered Memory Region allocation method to avoid memory waste.