AN EXPERIMENT IN RUST

Small by choice.
Built to learn.

An in-memory database inspired by Redis. Explore networking, concurrency and persistence in a codebase you can actually understand.

Read the docs Explore the code

Rust + TokioOpen sourceMIT / Apache-2.0

memorust — redis-cli

# A conversation with Memorust

$ redis-cli -p 6379

127.0.0.1:6379 > SET name Roberto

127.0.0.1:6379 > GET name

"Roberto"

127.0.0.1:6379 > PING

PONG

01 / SET. GET. Understand.

In-memory key-valueRESP protocolTTLAOF persistence

THE FUNDAMENTALS, HANDS ON

What it does

A focused subset of Redis, implemented from scratch with readability as the goal.

RESP protocol

Speaks the Redis Serialization Protocol, so redis-cli and existing Redis clients connect with no changes.

Async TCP server

Built on Tokio with concurrent client support and concurrent reads under a shared lock.

TTL & expiration

SETEX, EXPIRE and TTL with a background cleaner that reclaims expired keys.

AOF persistence

Append Only File with a buffered writer, periodic fsync (~1s) and replay on startup.

AOF rewrite

Compacts the log with AOFREWRITE so the on-disk history stays small.

Single binary, one dependency

Rust edition 2024 with Tokio as the only dependency. Easy to build, read and hack on.

QUICK START

Start at the terminal

Clone, build and connect with any Redis client.

Rust 1.85+ · redis-cli to connect

Read the docs

Terminal

git clone https://github.com/robertolima-dev/memorust.git
cd memorust
cargo run

# In another terminal

redis-cli -p 6379

MEASURING IS LEARNING

Fast where it counts

redis-benchmark on a release build, Apple M-series development machine.

GET · PIPELINE 16~1.27M

operations per second

Operation	No pipeline (-P 1)	Pipelined (-P 16)
SET	~142k ops/sec	~264k ops/sec
GET	~163k ops/sec	~1.27M ops/sec

Reference results; performance varies by environment.

Without pipelining the benchmark is dominated by network round-trips. Under pipelining the server ceiling shows: reads scale far past writes because GET runs concurrently under a shared lock.

COMMAND REFERENCE

Supported commands

A growing subset of the Redis command set.

Connection

PING

Key / Value

SET
GET
DEL
EXISTS

Expiration

SETEX
EXPIRE
TTL

Administration

INFO
FLUSHALL
AOFREWRITE

WORK IN PROGRESS

Roadmap

Where Memorust is heading next.

Open an issue

Implemented

TCP server & RESP protocol
redis-cli compatibility
TTL & background cleaner
AOF, replay & rewrite
Buffered AOF writer (appendfsync everysec)

Up next

Async AOF writer
Value types (Integer, JSON, List)
Config.toml
Memory eviction policies
Binary snapshot (.db)
Replication
Cluster mode

BUILT IN THE OPEN

Join the project

Memorust is open source and contributions are very welcome, from typo fixes to new commands.

Contribute

Read the development workflow, required checks and how to open a pull request.

Contributing guide

Issues & ideas

Found a bug or want to discuss a feature? Open an issue on GitHub.