redis

Redis

Configure, operate, and optimize Redis for caching, queues, rate limiting, and real-time data storage.

When to Use

• You need a low-latency in-memory cache to reduce database load.
• Your application requires rate limiting, session storage, or leaderboards.
• You need pub/sub messaging between services.
• You want a distributed lock or job queue backed by an in-memory store.

Prerequisites

• Linux server or Docker.
• Root or sudo access for package installation.
• Redis 7.x recommended for production.

Installation and Setup

# Debian / Ubuntu
sudo apt update
sudo apt install -y redis-server

# RHEL / Amazon Linux
sudo dnf install -y redis

# Start and enable
sudo systemctl enable --now redis-server

# Verify
redis-cli ping
# Expected output: PONG

Core Configuration

Edit /etc/redis/redis.conf:

# Network
bind 0.0.0.0
port 6379
protected-mode yes
requirepass strong_redis_password

# Memory
maxmemory 2gb
maxmemory-policy allkeys-lru

# Connections
maxclients 10000
timeout 300
tcp-keepalive 60

# Logging
loglevel notice
logfile /var/log/redis/redis-server.log

# Security — disable dangerous commands in production
rename-command FLUSHALL ""
rename-command FLUSHDB ""
rename-command CONFIG ""
rename-command DEBUG ""

sudo systemctl restart redis-server

redis-cli Commands Reference

# Connect with authentication
redis-cli -a strong_redis_password

# Connect to a remote host
redis-cli -h 10.0.0.5 -p 6379 -a strong_redis_password

String Operations

SET user:1:name "Alice"
GET user:1:name

# Set with TTL (seconds)
SETEX session:abc123 3600 '{"userId":1}'

# Set only if key does not exist (distributed lock pattern)
SET lock:order:42 "worker-1" NX EX 30

# Increment counters
INCR page:views:/home
INCRBY api:quota:user:1 -1

Hash Operations

HSET user:1 name "Alice" email "[email protected]" plan "pro"
HGET user:1 email
HGETALL user:1
HINCRBY user:1 login_count 1

List Operations (Queues)