Persistent key-value stores (pKVS) such as RocksDB are critical to many internet-scale services. Recent works leveraged persistent memory (PM) to improve pKVS throughput. However, they are typically limited to CPUs. We develop H-Rocks to judiciously leverage both the CPU and the Graphics Processing Unit (GPU) for accelerating a wide range of RocksDB operations. H-Rocks selectively accelerates performance-critical parts of RocksDB on the GPU. It uses operation sub-batching and key-value versioning to leverage GPU's parallelism while maintaining compatibility with RocksDB. It harnesses GPU's high-bandwidth memory while limiting data movement between the CPU and GPU. In YCSB workloads, H-Rocks outperforms CPU-based pKVSs like Viper, Plush, and pmem-RocksDB by 3-18×.

While the implications of persistent memory (PM) on CPU hardware and software are well-explored, the same is not true for GPUs (Graphics Processing Units). A recent work, GPM, demonstrated how GPU programs can benefit from the fine-grain persistence of PM. However, in the absence of a persistency model, one cannot reason about the correctness of PM-aware GPU programs. Persistency models define the order in which writes to PM are persisted. We explore persistency models for GPUs.

The GPU is a key computing platform for many application domains. While the new non-volatile memory technology has brought the promise of byte-addressable persistence (a.k.a., persistent memory, or PM) to CPU applications, the same, unfortunately, is beyond the reach of GPU programs.