HaCache: A Hybrid Adaptive Cache for Persistent Memory Based Key-Value Systems

Lixiao Cui, Gang Wang, Yusen Li, Xiaoguang Liu

Abstract: Many previous studies have proposed high-performance key-value systems based on Persistent memory (PM). However, these work ignores the fact that the read performance of PM is also lower than DRAM. In this paper, we propose HaCache, a well-designed hybrid cache for PM-based KV systems to improve read performance. HaCache combines key-value (KV) cache, key-pointer (KP) cache, and Block cache to retain the advantages of the three types of cache schemes. It can adaptively adjust the partition of cache space among the three cache schemes to adapt to workload changing. The evaluation results show that HaCache outperforms pure KV cache, pure KP cache, and pure Block cache by 2.7x, 2x, and 18% respectively.