ProxySQL Master-Slave MySQL Cluster

This repository provides a ready-to-use Docker Compose setup for a MySQL master-slave replication cluster managed by ProxySQL. It is ideal for testing, development, and learning about MySQL replication and ProxySQL load balancing.

Project Structure

• master/: MySQL master configuration and initialization.
• slave/: MySQL slave configurations and initialization.
• proxysql/: ProxySQL configuration and persistent data files.
• docker-compose.yml: Service definitions for master, slaves, and ProxySQL.

Services

1. mysql-master: MySQL master node (port 3306)
2. mysql-slave1: MySQL slave node 1 (port 3307)
3. mysql-slave2: MySQL slave node 2 (port 3308)
4. proxysql: ProxySQL instance (ports 6032 for admin, 6033 for MySQL traffic)

How to Run

1. Install Docker and Docker Compose

   • Make sure Docker is running on your system.

2. Clone this repository

   git clone https://github.com/sakibbuddy/proxysql_master_slave.git
   cd proxysql_master_slave

3. Start the cluster

   docker-compose up -d

4. Check service status

   docker-compose ps

5. Access MySQL and ProxySQL

   • MySQL Master: localhost:3306
   • MySQL Slave1: localhost:3307
   • MySQL Slave2: localhost:3308
   • ProxySQL Admin: localhost:6032
   • ProxySQL MySQL: localhost:6033

Notes

• Default MySQL root password is password (change in docker-compose.yml for production).
• Initialization SQL and custom configs are loaded from the respective folders.
• ProxySQL configuration is in proxysql/proxysql.cnf.

Stopping the Cluster

To stop and remove all containers:

docker-compose down

Troubleshooting

Problem	Possible Fix
❌ Replication lag or slaves not syncing	Check GTID settings and slave status (SHOW SLAVE STATUS\G)
❌ ProxySQL health check fails	Confirm monitor user credentials and hostgroups
❌ Can't connect to master/slave	Verify container ports, firewall, and network
🐳 Containers restart / crash	Inspect logs & check volume mounts
❗ ProxySQL not routing reads	Confirm query rules and hostgroup IDs

---

Feel free to modify configs for your own replication or ProxySQL experiments!