Dragonfly SSD Data Tiering: Caching All the Way Down

Dragonfly v1.21 introduces an alpha feature called SSD Data Tiering, which allows offloading of String data type values from memory to fast SSD storage. This intelligent management optimizes memory usage by keeping frequently accessed hot data in memory while moving less-used data to disk. Despite a slight decrease in throughput and increase in latency, the performance remains highly competitive with median and average latencies staying in the sub-millisecond range. The benefits of SSD tiering include optimized memory usage, cost-effective scaling, and support for large datasets. However, it is not suitable for applications requiring ultra-low latency or as a backup solution.