DragonflyDB — Modern In-Memory Datastore Replacing Redis

What DragonflyDB Does

• Redis compatible — RESP protocol, most Redis commands
• Memcached compatible — text and binary protocols
• Multi-threaded — shared-nothing, scales across all cores
• Memory efficient — novel data structures use ~40% less RAM
• Snapshots — RDB-compatible persistence
• Replication — Redis-compatible replication protocol
• Pub/Sub — full pub/sub support
• Lua scripting — Redis Lua scripts work unchanged
• Cluster mode — emulated cluster for Redis cluster clients
• ACL — Redis-compatible ACL system

Architecture

Shared-nothing multi-threaded design: each thread owns a slice of the keyspace. No global locks. Novel dashtable data structure replaces Redis dict for lower memory overhead and better cache locality. IO is handled via io_uring (Linux) for minimal syscall overhead.

Self-Hosting

version: "3"
services:
  dragonfly:
    image: docker.dragonflydb.io/dragonflydb/dragonfly
    ports: ["6379:6379"]
    volumes:
      - dragonfly-data:/data
    ulimits:
      memlock: -1
volumes:
  dragonfly-data:

Key Features

• Redis + Memcached wire compatibility
• 25x throughput vs Redis (single instance)
• 40% less memory usage
• Multi-threaded (shared-nothing)
• RDB snapshot persistence
• Replication
• Lua scripting
• ACL security
• io_uring (Linux)
• Drop-in replacement

Comparison

FAQ

Q: Can it directly replace Redis? A: Yes in most scenarios. The RESP protocol is compatible, and most Redis commands are supported. A few advanced Redis features (Redis Modules, some cluster edge behaviors) are not.

Q: BSL restrictions? A: Automatically converts to Apache 2.0 after 4 years. In the meantime, self-use is completely fine; you just can't run a managed Dragonfly service competing with the official one.

Q: Why is it so fast? A: Multithreading + lock-free shared-nothing + io_uring + compact data structures (dashtable). A single machine can saturate a 96-core server.

Sources

• Docs: https://www.dragonflydb.io/docs
• GitHub: https://github.com/dragonflydb/dragonfly
• License: BSL 1.1