Redis Best Practices

2026-03-28 989 words 5 minutes

Contents

Quick Start

Installation & Version

Current version is Redis 8.6.2.

macOS

        
# Install via Homebrew
brew install redis

# Start service
brew services start redis

# Or start manually
redis-server

# Connect
redis-cli

Windows

Redis doesn’t natively support Windows, but can be used via:

        
# Method 1: Use WSL2 (recommended)
# Install Redis in WSL2
sudo apt update && sudo apt install redis-server
sudo service redis-server start

# Method 2: Use Docker
docker run -d --name redis -p 6379:6379 redis:8.6.2-alpine

# Method 3: Download Microsoft-maintained Windows version (unofficial)

Linux (Ubuntu)

        
# Update and install
sudo apt update
sudo apt install -y redis-server

# Start service
sudo systemctl start redis-server
sudo systemctl enable redis-server

# Or start manually
redis-server

# Connect
redis-cli

Docker Compose Deployment

        
        
        
    
services:
  redis:
    image: redis:8-alpine
    container_name: redis
    restart: unless-stopped
    ports:
      - "6379:6379"
    command: redis-server --requirepass password123
    volumes:
      - redis_data:/data
    healthcheck:
      test: ["CMD", "redis-cli", "-a", "password123", "ping"]
      interval: 10s
      timeout: 5s
      retries: 5

volumes:
  redis_data:

Start: docker compose up -d

Connect: redis-cli -h localhost -p 6379 -a password123

Basic Operations

        
# Test connection
PING

# View all keys
SCAN 0

# Basic data type operations
SET name "Alice"
GET name
DEL name

# View info
INFO

Data Types

String

        
        
        
    
# Basic operations
SET name "Alice"
GET name
MGET name age  # Batch get
MSET name "Alice" age 30  # Batch set

# Counter operations
SET counter 100
INCR counter      # 101
INCRBY counter 10  # 111
DECR counter       # 110

# Set with expiration
SET token "abc123" EX 3600  # 1 hour
TTL token  # Check remaining time

Hash

        
# Create hash
HSET user:1 name "Alice" email "[email protected]" age 30

# Get fields
HGET user:1 name
HMGET user:1 name email

# Get all fields
HGETALL user:1

# Increment
HINCRBY user:1 age 1

List

        
        
        
    
# Add elements
LPUSH tasks "task1"
RPUSH tasks "task2"
LPUSH tasks "task0"

# Get range
LRANGE tasks 0 -1  # Get all

# Pop elements
LPOP tasks
RPOP tasks

Set

        
        
        
    
# Add members
SADD tags "redis" "database" "cache"

# Get members
SMEMBERS tags
SISMEMBER tags "redis"

# Intersection, Union, Difference
SINTER tag1 tag2
SUNION tag1 tag2
SDIFF tag1 tag2

Sorted Set

        
        
        
    
# Add members with score
ZADD leaderboard 100 "Alice"
ZADD leaderboard 200 "Bob"
ZADD leaderboard 150 "Charlie"

# Get by score
ZRANGE leaderboard 0 -1 WITHSCORES

# Get rank
ZRANK leaderboard "Alice"
ZREVRANK leaderboard "Alice"

Stream

New in Redis 8.x, for message queues:

        
# Create stream
XADD mystream * sensor-id temp 25.5

# Read stream
XRANGE mystream - +

# Consumer group
XGROUP CREATE mystream mygroup $

# Read new messages
XREADGROUP GROUP mygroup consumer1 COUNT 10 STREAMS mystream ">"

Caching Strategies

Cache Patterns

        
# Cache-Aside
# 1. Read: Check cache first, fallback to DB, write to cache
# 2. Update: Update DB first, then delete cache

# Write-Through
# Write to both cache and DB simultaneously

# Write-Behind
# Write to cache only, batch write to DB periodically

Expiration Policies

        
        
        
    
# Set expiration
EXPIRE user:1 3600  # 1 hour
EXPIREAT user:1 1735689600  # Unix timestamp

# Lazy expiration: Check when accessed
# Periodic expiration: Random check every 100ms

# Memory eviction policies
# noeviction: Return error
# allkeys-lru: Evict least recently used
# volatile-lru: Evict LRU from expired keys
# allkeys-random: Random eviction
# volatile-random: Random from expired keys
# volatile-ttl: Evict shortest TTL

Cache Problems

        
# Cache穿透: Bloom filter or cache null values
SET cache:bloom:users "exists"

# Cache击穿: Mutex or logical expiration
# Use RedLock for distributed lock

# Cache雪崩: Add random jitter to TTL, persistence + multi-level cache

Persistence

RDB (Snapshot)

        
        
        
    
# Configuration
save 900 1      # Save if 1 key changed in 900 seconds
save 300 10     # Save if 10 keys changed in 300 seconds
save 60 10000   # Save if 10000 keys changed in 60 seconds

# Manual trigger
BGSAVE
SAVE

# Check last save time
LASTSAVE

AOF (Append Only File)

        
# Enable AOF
appendonly yes

# Sync policies
appendfsync always     # Sync every write
appendfsync everysec    # Sync every second (default)
appendfsync no          # Let OS decide

# Rewrite and compress
BGREWRITEAOF

Hybrid Persistence

        
# Enable hybrid persistence
aof-use-rdb-preamble yes

Clustering

Master-Replica

        
# Configure replica
replicaof master-ip master-port

# Stop replication
REPLICAOF NO ONE

# Check replication status
INFO replication

Sentinel

        
# Monitor master
sentinel monitor mymaster 127.0.0.1 6379 2

# Automatic failover
# Sentinel elects new master automatically

Cluster

        
# Create cluster
redis-cli --cluster create 127.0.0.1:7001 127.0.0.1:7002 127.0.0.1:7003 \
  --cluster-replicas 1

# Check cluster status
redis-cli -p 7001 cluster info

# Reshard
redis-cli --cluster reshard 127.0.0.1:7001

Cluster Slots

        
# View slot allocation
redis-cli cluster slots

# Manual slot assignment
redis-cli -p 7001 cluster addslots 0 1 2 3 4

Security

Authentication

        
# Set password
CONFIG SET requirepass "your_password"

# Authenticate
AUTH your_password

# Or in command line
redis-cli -a your_password

ACL

        
        
        
    
# Create user
ACL SETUSER alice ON >password ~cached:* -@all +get +set +del

# List users
ACL LIST

# Permission syntax
# + grant permission
# - revoke permission
# @ grant permission category
# ~ add key pattern

Secure Configuration

        
# Disable dangerous commands
rename-command FLUSHALL ""
rename-command CONFIG "CONFIG_b45a0e32"

# Bind address
bind 127.0.0.1

# Disable protected mode
protected-mode yes

Performance Optimization

Slow Query

        
# View slow query log
SLOWLOG GET

# Set threshold (microseconds)
CONFIG SET slowlog-log-slower-than 1000

# Max slow log entries
CONFIG SET slowlog-max-len 100

Memory Optimization

        
# Check memory usage
INFO memory
MEMORY STATS

# Defragment
MEMORY PURGE

# Find big keys
redis-cli --bigkeys

Connection Optimization

        
# Max clients
CONFIG SET maxclients 10000

# TCP tuning
CONFIG SET tcp-backlog 511
CONFIG SET tcp-keepalive 300

Common Commands Reference

Command	Description
`SET key value`	Set string value
`GET key`	Get value
`DEL key`	Delete key
`EXISTS key`	Check if key exists
`EXPIRE key seconds`	Set expiration
`KEYS pattern`	Pattern matching
`SCAN cursor`	Progressive iteration
`INFO`	View Redis info
`DBSIZE`	Key count
`FLUSHDB`	Clear current DB
`FLUSHALL`	Clear all DBs