Achieving higher performance of memcached by caching at network interface

Abstract

As the volume of data that web services handle is becoming larger, many web service providers are utilizing memcached, an in-memory key-value store to improve their web server's performance. While memcached usually runs on a server with a high performance processor, various hardware platforms has been evaluated for running memcached in order to achieve higher performance. Recently, several works that use FPGAs have successfully achieved higher performance than Xeon. These works, however, struggles to utilize a large memory with FPGAs. In this paper, we propose a system that enables us to overcome this problem and enhances memcached by caching a part of software memcached's commands and data to the network interface card equipped with an FPGA and a DRAM. Our evaluation showed that the NIC cache has less than 30% of hit rate for workload with Latest key selection distribution, and 30% to 60% for Zipf distribution workloads.