We just released the Hailstorm code publicly! The license is Apache 2, so feel free to head over to Github and take it out for a spin!
Hailstorm is a system designed to improve load balance and resource utilization in existing LSM-based distributed databases. Hailstorm is deployed as a filesystem underneath LSM storage engines such as RocksDB and spreads all data uniformly across all storage devices within a rack in fine-grained blocks. We leverage this storage design to enable database instances with a high load to offload compaction tasks to other less utilized machines in the system.