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Alex Spinov
Alex Spinov

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Dragonfly Has a Free API: The Redis-Compatible Cache That's 25x Faster

Redis is single-threaded. In 2026, your server has 64 cores. Dragonfly uses all of them.

What Is Dragonfly?

Dragonfly is a Redis/Memcached-compatible in-memory datastore that's multi-threaded by design. Same API, same commands, 25x more throughput on modern hardware.

# Drop-in Redis replacement
docker run --ulimit memlock=-1 -p 6379:6379 docker.dragonflydb.io/dragonflydb/dragonfly

# Use your existing Redis client — no changes needed
redis-cli -p 6379
> SET hello world
> GET hello
"world"
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Why Dragonfly Over Redis

1. Multi-threaded — Redis uses 1 core. Dragonfly uses all cores. On a 64-core machine, that's 25x more throughput.

2. Memory efficient — Dragonfly uses up to 40% less memory for the same dataset. Its novel data structure (dash table) is more compact than Redis's hash tables.

3. Snapshots without forks — Redis forks the process for RDB snapshots, temporarily doubling memory usage. Dragonfly snapshots without forking.

Metric Redis Dragonfly
Throughput (64 cores) 400K ops/s 4M ops/s
Memory for 10M keys 1.5GB 900MB
Snapshot memory spike 2x None
Max connections ~10K 1M+

Compatibility

# Python — same redis-py library
import redis
r = redis.Redis(host='localhost', port=6379)
r.set('key', 'value')
r.get('key')  # b'value'
r.lpush('list', 'a', 'b', 'c')
r.hset('hash', mapping={'field1': 'val1', 'field2': 'val2'})
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All Redis commands work: strings, lists, sets, sorted sets, hashes, streams, pub/sub, Lua scripts, transactions.

When to Switch

  • You're scaling Redis with clusters → try single Dragonfly instance first
  • Your Redis forks cause memory spikes → Dragonfly doesn't fork
  • You need >500K ops/s → Dragonfly scales with CPU cores
  • Your Redis memory costs are high → Dragonfly uses 40% less

Building high-performance caching? Check out my developer tools or email spinov001@gmail.com.

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