MongoDB is a super flexible NoSQL database, and if you’re running it on Debian 12 (Bookworm), setting up Master-Slave (Primary-Secondary) replication can help with scaling and data redundancy.
This guide will take you through installing, running, and configuring MongoDB 8 for a master-slave setup.
Prerequisites
- 3 Debian 12 servers:
- Primary (Master):
10.11.33.111 - Secondary 1 (Slave):
10.11.33.121 - Secondary 2 (Slave):
10.11.33.122
- Primary (Master):
- Root or sudo access on all servers
- Basic terminal knowledge (copy-paste helps too!)
Step 1: Install MongoDB 8 on Debian 12
1.1. Update Your System
Run this to make sure everything is fresh:
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sudo apt update && sudo apt upgrade -y |
1.2. Add the MongoDB Repo
MongoDB isn’t included in the default Debian repo, so we gotta add it manually.
- Install gnupg and curl :
sudo apt-get install gnupg curl - Add MongoDB’s GPG key:
curl -fsSL https://pgp.mongodb.com/server-8.0.asc | sudo tee /usr/share/keyrings/mongodb-server-8.gpg - Add the official repo:
echo "deb [ signed-by=/usr/share/keyrings/mongodb-server-8.0.gpg ] http://repo.mongodb.org/apt/debian bookworm/mongodb-org/8.0 main" | sudo tee /etc/apt/sources.list.d/mongodb-org-8.0.list - Update package lists:
sudo apt update
1.3. Install MongoDB
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sudo apt install -y mongodb-org |
1.4. Start and Enable MongoDB
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sudo systemctl enable mongod sudo systemctl start mongod |
1.5. Check If It’s Running
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sudo systemctl status mongod |
If you see Active (running), MongoDB is alive!
Step 2: Configure Master-Slave Setup
2.1. Setup the Master (Primary) Server
- Open the MongoDB config:
sudo nano /etc/mongod.conf - Edit these lines:
net: bindIp: 0.0.0.0 port: 27017 replication: replSetName: "rs0" - Restart MongoDB:
sudo systemctl restart mongod
2.2. Setup the Slaves (Secondary Servers)
Do this on 10.11.33.121 and 10.11.33.122:
- Edit MongoDB config:
sudo nano /etc/mongod.conf - Same changes as above:
net: bindIp: 0.0.0.0 port: 27017 replication: replSetName: "rs0" - Restart MongoDB:
sudo systemctl restart mongod
Step 3: Initialize the Replica Set
On the Primary (Master) Server 10.11.33.111, run:
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mongosh |
Then, initiate the replica set:
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rs.initiate({ _id: "rs0", members: [ { _id: 0, host: "10.11.33.111:27017" }, { _id: 1, host: "10.11.33.121:27017" }, { _id: 2, host: "10.11.33.122:27017" } ] }); |
Check if it’s working:
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rs.status() |
If it shows one Primary and two Secondaries, congrats, it’s working!
Step 4: Secure MongoDB with Authentication
By default, MongoDB is wide open! Let’s lock it down.
4.1. Create an Admin User
Run this on the Primary Server:
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mongosh |
Then add an admin:
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use admin; db.createUser({ user: "admin", pwd: "SuperStrongPass123!", roles: [{ role: "root", db: "admin" }] }); |
4.2. Enable Authentication
Edit MongoDB config on all servers:
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sudo nano /etc/mongod.conf |
Add:
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security: authorization: enabled |
Restart MongoDB:
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sudo systemctl restart mongod |
4.3. Verify
Try logging in:
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mongosh -u admin -p SuperStrongPass123! --authenticationDatabase admin |
Step 5: Test the Replication
5.1. Insert Data on Primary
On the Primary Server (10.11.33.111):
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use testdb; db.products.insertOne({ name: "Laptop", price: 1200 }); |
5.2. Read Data from Secondary
On a Secondary Server (10.11.33.121):
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mongosh -u admin -p SuperStrongPass123! --authenticationDatabase admin |
Enable reading from the slave:
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rs.slaveOk(); use testdb; db.products.find(); |
If you see { "name": "Laptop", "price": 1200 }, replication is working!
Step 6: Auto-Start MongoDB on Boot
Ensure MongoDB starts automatically:
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sudo systemctl enable mongod |
Final Thoughts
Boom! 💥 You now have a MongoDB 8 Master-Slave (Primary-Secondary) setup running on Debian 12. It’s secured, replicated, and production-ready.
Next Steps
- Backups: Use
mongodumpandmongorestorefor safe data backups. - Monitoring: Run
mongostatandmongotopto track performance. - Sharding: If you need even more scale, look into MongoDB sharding.
For more cool guides, check out diditho.com! 🚀