Fully Transparent Client-Side Caching for Key-Value Store Applications Using FPGAs

Key-value stores (KVS) are a critical component of current data center infrastructure. They help address the extreme demand on data centers for high bandwidth, low latency access to large amounts of data. Due to their importance, many efforts have been made to improve their performance, which includes using FPGAs to offload some functionality. These efforts have been focused on improving the performance of the key-value store itself and reducing the load on the server running the KVS. However, with more FPGAs being deployed in the data centers by many cloud service providers, some use models that were not previously practical are becoming more realistic. In this work, we explore one such use case where we attempt to cache key-value entries at the network interface of the client server. We propose an FPGA design that is capable of caching the KVS data transparently to the KVS client application. The proposed solution is able to improve the application throughput while also reducing the network traffic generated by the KVS client. Also, as the proposed solution targets client servers that are typically shared by multiple clients, we discuss the importance of, and present our vision for, an FPGA design supporting multiple tenants.