MaelstromDB

MaelstromDB is a toy implementation of a distributed SQL database using the Raft protocol.

Raft Features

• Leader election
• Log replication
• Cluster membership changes, dynamically add/remove servers to cluster
• Linearizable semantics for clients
• Group commits, to improve write throughput
• Leader leases, to serve reads from Leader without consulting Followers to reduce read latency
• Snapshots, to prevent unbounded growth of log

Prerequisites

The database was tested with the following versions of docker and docker-compose,

• docker >= 20.10.5
• docker-compose >= 1.29.0

Usage

To create a 3 node cluster run,

docker-compose build
docker-compose up -d node1 node2 node3
docker-compose run admin

This should open a shell from which the cluster can be connected with,

./maelstromcli reconfigure --cluster=node1:3000 node1:3000,node2:3000,node3:3000

To write key-value pairs run,

./maelstromcli write --cluster=node1:3000,node2:3000,node3:3000 $key:$value

substituting $key and $value with the key value pair. To read data run,

./maelstromcli query --cluster=node1:3000,node2:3000,node3:3000 $key

substituting $key with the known key.