Setup Guide

Understanding Redis

Redis is an in-memory data structure store that can be used as a database, cache, message broker, and queue. This guide will help you install and secure Redis with custom configurations.

Installation Process

Update package lists and install Redis:

# Update package lists to ensure we get the latest version
sudo apt update

# Install Redis server package
sudo apt install redis-server

Detailed Configuration

Redis configuration is managed through the redis.conf file. We'll make several important modifications:

1. First, backup your original configuration:

# Create a backup before making changes
sudo cp /etc/redis/redis.conf /etc/redis/redis.conf.backup

# Edit Redis configuration
sudo nano /etc/redis/redis.conf

2. Essential Configuration Settings:

# Network Configuration
port 35000                  # Custom port instead of default 6379
bind 0.0.0.0               # Allow external connections (be careful with this)
protected-mode yes         # Additional network security

# Authentication
requirepass YourStrongPasswordHere    # Set a strong password (min 32 chars recommended)

# Memory Management
maxmemory 1gb             # Limit Redis memory usage
maxmemory-policy allkeys-lru  # Eviction policy when memory limit is reached

# Performance Tuning
tcp-keepalive 300         # Keep connections alive
timeout 0                 # Client connection timeout (0 = disabled)
tcp-backlog 511           # Connection queue length
databases 16              # Number of database instances

# Persistence Configuration
appendonly yes            # Enable AOF persistence
appendfilename "appendonly.aof"
appendfsync everysec      # Fsync policy (always/everysec/no)

Security Implementation

Redis security is crucial when exposed to external connections:

1. Firewall Configuration:

# Allow specific IPv4 addresses
sudo ufw allow from 192.168.1.100 to any port 35000 proto tcp comment 'Redis - Application Server'
sudo ufw allow from 192.168.1.101 to any port 35000 proto tcp comment 'Redis - Backup Server'

# Allow specific IPv6 addresses if needed
sudo ufw allow from 2001:db8::1 to any port 35000 proto tcp comment 'Redis - IPv6 Client'

Service Management

Control and monitor Redis service:

1. Service Controls:

# Start Redis service
sudo systemctl start redis-server

# Enable Redis to start on boot
sudo systemctl enable redis-server

# Restart Redis after configuration changes
sudo systemctl restart redis-server

2. Verify Installation:

# Connect to Redis
redis-cli -p 35000

# Authenticate
auth YourStrongPasswordHere

# Test connection
ping

Expected successful response:

PONG

Monitoring and Maintenance

1. Service Status:

# Check service status
sudo systemctl status redis-server

# View logs
sudo tail -f /var/log/redis/redis-server.log

2. Performance Monitoring:

# Connect to Redis with password
redis-cli -p 35000 -a YourStrongPasswordHere

# Check memory usage
INFO memory

# Monitor connected clients
CLIENT LIST

# Get server statistics
INFO stats

Troubleshooting

Common issues and solutions:

1. Connection refused:
   • Check if Redis is running: sudo systemctl status redis-server
   • Verify port is open: sudo ss -tulpn | grep 35000
   • Check firewall rules: sudo ufw status numbered
2. Authentication failed:
   • Verify password in configuration
   • Check if requirepass is set correctly
   • Ensure no typos in authentication command
3. Memory issues:
   • Monitor memory usage: redis-cli -p 35000 -a YourStrongPasswordHere INFO memory
   • Adjust maxmemory setting if needed
   • Review eviction policy effectiveness

Best Practices

1. Memory Configuration:
   • Set maxmemory to 70-80% of available RAM
   • Choose appropriate eviction policy
   • Monitor memory usage regularly
2. Security:
   • Use strong passwords (32+ characters)
   • Limit access to specific IPs
   • Regularly update Redis to patch security issues
   • Disable dangerous commands in production
3. Backup:
   • Enable AOF persistence for data safety
   • Schedule regular RDB snapshots
   • Test backup restoration procedures