dragonflydb/dragonfly

Analysis updated 2026-06-20

★ 30,444C++Audience · ops devopsComplexity · 4/5Setup · moderate

Mindmap

mindmap
  root((dragonfly))
    What It Does
      In-memory data store
      Redis replacement
      Multi-core scaling
    Key Advantages
      Up to 25x throughput
      Less memory usage
      No code changes needed
    Compatibility
      Redis commands
      Memcached commands
    Use Cases
      High-traffic caching
      Smaller server costs
      Redis bottleneck fix

mindmap root((dragonfly)) What It Does In-memory data store Redis replacement Multi-core scaling Key Advantages Up to 25x throughput Less memory usage No code changes needed Compatibility Redis commands Memcached commands Use Cases High-traffic caching Smaller server costs Redis bottleneck fix

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What do people build with it?

USE CASE 1

Replace Redis with Dragonfly on a multi-core server to handle far more requests without changing any application code

USE CASE 2

Run the same caching workload on smaller, cheaper server instances by using Dragonfly's multi-threaded design

USE CASE 3

Scale an application's in-memory cache throughput without migrating to a Redis Cluster

USE CASE 4

Replace Memcached with Dragonfly while keeping all existing client code and connection strings unchanged

What is it built with?

C++

How does it compare?

	dragonflydb/dragonfly	facebook/folly	freecad/freecad
Stars	30,444	30,362	30,774
Language	C++	C++	C++
Setup difficulty	moderate	hard	easy
Complexity	4/5	4/5	3/5
Audience	ops devops	developer	general

Figures from each repo's GitHub metadata at analysis time.

How do you get it running?

Difficulty · moderate Time to first run · 30min

Runs via Docker with a single command, requires updating your app's Redis connection string to point at Dragonfly instead.

In plain English

Dragonfly is an in-memory data store, a database that keeps all its data in RAM rather than on disk, which makes reads and writes extremely fast. It is designed as a drop-in replacement for Redis and Memcached, two widely-used in-memory stores. Because Dragonfly implements the same commands and connection protocol as Redis and Memcached, existing applications can switch to it without changing any of their code. The core problem Dragonfly addresses is that Redis is fundamentally single-threaded: it can only use one CPU core at a time. On modern servers with many cores, this becomes a ceiling on performance. Dragonfly is built from the ground up to use all available CPU cores simultaneously using a technique called fibers (lightweight threads managed within the program rather than by the operating system). According to the README's benchmarks, this allows Dragonfly to deliver up to 25 times more request throughput than Redis on high-core-count machines, while also using significantly less memory, the README reports 30% better memory efficiency in idle state and far less memory spike during data snapshots. An operations team or backend developer would switch to Dragonfly when Redis is becoming the performance bottleneck in their system, when they want the same caching behavior but on smaller, cheaper server instances, or when they need to handle higher throughput without horizontally scaling to a Redis cluster. It is written in C++ and is fully compatible with Redis API commands and Memcached commands.

Copy-paste prompts

Prompt 1

How do I switch from Redis to Dragonfly, what do I change in my application config and connection string?

Prompt 2

What docker run command starts a Dragonfly instance that accepts connections on the default Redis port 6379?

Prompt 3

How do I benchmark Dragonfly versus Redis on my server using redis-benchmark to measure the throughput difference?

Prompt 4

Which Redis commands or features are not yet supported in Dragonfly and what are the workarounds?

Prompt 5

How do I configure Dragonfly to limit which CPU cores it uses on a shared server?

Frequently asked questions

What is dragonfly?

Dragonfly is a drop-in replacement for Redis that uses all CPU cores simultaneously, delivering up to 25x more throughput on modern servers while using less memory, with zero application code changes.

What language is dragonfly written in?

Mainly C++. The stack also includes C++.

How hard is dragonfly to set up?

Setup difficulty is rated moderate, with roughly 30min to a first successful run.

Who is dragonfly for?

Mainly ops devops.

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