Lux vs Dragonfly
Dragonfly is a heavy-duty Redis replacement. Lux is the lightweight alternative.
| Feature | Lux | Dragonfly |
|---|---|---|
| Language | Rust | C++ |
| Vector search | Built-in (VSET/VSEARCH) | Not supported |
| Binary size | ~2MB | ~45MB |
| Memory overhead | Minimal | Significant (dash memory allocator) |
| Target use case | Lightweight, fast, simple | Large-scale, feature-rich |
| Threading | 128 shards | Shared-nothing per-thread |
| License | MIT | BSL 1.1 (source-available, not OSS) |
| Managed hosting | Lux Cloud ($10/mo per project) | Dragonfly Cloud ($$$$) |
| Minimum RAM | ~4MB | ~500MB |
Why Lux over Dragonfly?
Dragonfly is optimized for large-scale deployments with massive datasets. It's impressive technology but comes with a heavy footprint (500MB+ minimum RAM) and a BSL license that restricts commercial use. Lux is MIT licensed, starts in under 4MB of RAM, and covers the key-value use cases most applications actually need.
When to use Dragonfly instead
If you're managing 100GB+ datasets, need Lua scripting, or require Dragonfly's advanced memory management, it's the right choice. For most applications doing caching, sessions, queues, or real-time data with datasets under 10GB, Lux is dramatically simpler and cheaper.