MemcachedGPU: Scaling-up Scale-out Key-value Stores

This paper tackles the challenges of obtaining more efficient data center computing while maintaining low latency, low cost, programmability, and the potential for workload consolidation. We introduce GNoM, a software framework enabling energy-efficient, latency bandwidth optimized UDP network and application processing on GPUs. GNoM handles the data movement and task management to facilitate the development of high-throughput UDP network services on GPUs. We use GNoM to develop MemcachedGPU, an accelerated key-value store, and evaluate the full system on contemporary hardware. MemcachedGPU achieves ~10 GbE line-rate processing of ~13 million requests per second (MRPS) while delivering an efficiency of 62 thousand RPS per Watt (KRPS/W) on a high-performance GPU and 84.8 KRPS/W on a low-power GPU. This closely matches the throughput of an optimized FPGA implementation while providing up to 79% of the energy-efficiency on the low-power GPU. Additionally, the low-power GPU can potentially improve cost-efficiency (KRPS/$) up to 17% over a state-of-the-art CPU implementation. At 8 MRPS, MemcachedGPU achieves a 95-percentile RTT latency under 300μs on both GPUs. An offline limit study on the low-power GPU suggests that MemcachedGPU may continue scaling throughput and energy-efficiency up to 28.5 MRPS and 127 KRPS/W respectively.