Multilevel NoSQL Cache Combining In-NIC and In-Kernel Approaches

Key-value store accelerators based on field-programmable gate arrays (FPGAs) have been proposed to achieve higher performance per watt than software-based processing. However, because their cache capacity is strictly limited by DRAMs implemented on FPGA boards, their application domains are also limited. To address this issue, the authors propose a multilevel NoSQL cache architecture that utilizes both FPGA-based hardware cache and in-kernel software cache in a complementary style. This motivates them to explore various design options. Simulation results show that their design reduces the cache miss ratio and improves the throughput compared to the nonhierarchical design.