MongoDB

Administer MongoDB NoSQL databases.

Installation & Setup

# Install
apt install mongodb-org

# Start service
systemctl start mongod

# Connect
mongosh

# Create user
use admin
db.createUser({
  user: "admin",
  pwd: "secret",
  roles: ["root"]
})

Basic Operations

// Create database and collection
use mydb
db.users.insertOne({ name: "John", email: "john@example.com" })

// Query
db.users.find({ name: "John" })
db.users.find().sort({ name: 1 }).limit(10)

// Index
db.users.createIndex({ email: 1 }, { unique: true })

Replica Set

// Initialize replica set
rs.initiate({
  _id: "myReplicaSet",
  members: [
    { _id: 0, host: "mongo1:27017" },
    { _id: 1, host: "mongo2:27017" },
    { _id: 2, host: "mongo3:27017" }
  ]
})

Backup

# Backup
mongodump --out /backup/

# Restore
mongorestore /backup/

Best Practices

• Use replica sets in production
• Implement proper indexing
• Enable authentication
• Regular backups with mongodump