RocksDB

Overview

RocksDB is a log-structured merge (LSM) key-value store that the 2025 OCP Global Summit FDP panel repeatedly used as the canonical benchmark for demonstrating Flexible Data Placement (FDP) write-amplification benefits. Its log-structured merge design makes data-placement benefits show clearly, so speakers "hammered" it for nearly every test. With FDP, RocksDB drive write amplification factor (WAF) was brought very close to one; Kioxia's U-Frog RocksDB plugin (using io_uring to bypass the file system) drove drive WAF to ~1.0 and lifted query throughput from ~8,000 to ~15,000 queries per second, while total WAF — including RocksDB's own compaction and file-system metadata — fell dramatically but remained above 1.0.