Redis

Verify Connection

# redis-cli
redis-cli -u "$REDIS_URL" PING

# Upstash
curl -s "$UPSTASH_REDIS_REST_URL/ping" \
  -H "Authorization: Bearer $UPSTASH_REDIS_REST_TOKEN" | jq .

redis-cli Recipes

String Operations

# Set a value
redis-cli -u "$REDIS_URL" SET mykey "myvalue"

# Set with expiry (60 seconds)
redis-cli -u "$REDIS_URL" SET mykey "myvalue" EX 60

# Get a value
redis-cli -u "$REDIS_URL" GET mykey

# Delete a key
redis-cli -u "$REDIS_URL" DEL mykey

# Set multiple keys
redis-cli -u "$REDIS_URL" MSET key1 "val1" key2 "val2" key3 "val3"

# Get multiple keys
redis-cli -u "$REDIS_URL" MGET key1 key2 key3

Key Management

# Scan keys (safe for production — non-blocking)
redis-cli -u "$REDIS_URL" SCAN 0 MATCH "prefix:*" COUNT 100

# Get key type
redis-cli -u "$REDIS_URL" TYPE mykey

# Get TTL (time to live)
redis-cli -u "$REDIS_URL" TTL mykey

# Set expiry on existing key
redis-cli -u "$REDIS_URL" EXPIRE mykey 3600

Hash Operations

# Set hash fields
redis-cli -u "$REDIS_URL" HSET user:1 name "Alice" email "[email protected]" role "admin"

# Get one field
redis-cli -u "$REDIS_URL" HGET user:1 name

# Get all fields
redis-cli -u "$REDIS_URL" HGETALL user:1

List Operations

# Push to list
redis-cli -u "$REDIS_URL" RPUSH queue "task1" "task2" "task3"

# Pop from list
redis-cli -u "$REDIS_URL" LPOP queue

# Get list range
redis-cli -u "$REDIS_URL" LRANGE queue 0 -1

# List length
redis-cli -u "$REDIS_URL" LLEN queue

Set Operations

# Add to set
redis-cli -u "$REDIS_URL" SADD tags "python" "javascript" "typescript"

# Get all members
redis-cli -u "$REDIS_URL" SMEMBERS tags

# Check membership
redis-cli -u "$REDIS_URL" SISMEMBER tags "python"

Sorted Set Operations

# Add with scores
redis-cli -u "$REDIS_URL" ZADD leaderboard 100 "alice" 85 "bob" 92 "charlie"

# Get top scores
redis-cli -u "$REDIS_URL" ZREVRANGE leaderboard 0 9 WITHSCORES

# Increment score
redis-cli -u "$REDIS_URL" ZINCRBY leaderboard 5 "bob"

Server Info

# Memory usage
redis-cli -u "$REDIS_URL" INFO memory

# Database size (key count)
redis-cli -u "$REDIS_URL" DBSIZE

Upstash REST API Recipes

For serverless Redis (no redis-cli needed):

GET / SET

# SET
curl -s "$UPSTASH_REDIS_REST_URL/set/mykey/myvalue" \
  -H "Authorization: Bearer $UPSTASH_REDIS_REST_TOKEN"

# SET with EX (expiry in seconds)
curl -s "$UPSTASH_REDIS_REST_URL/set/mykey/myvalue/ex/60" \
  -H "Authorization: Bearer $UPSTASH_REDIS_REST_TOKEN"

# GET
curl -s "$UPSTASH_REDIS_REST_URL/get/mykey" \
  -H "Authorization: Bearer $UPSTASH_REDIS_REST_TOKEN" | jq '.result'

# DEL
curl -s "$UPSTASH_REDIS_REST_URL/del/mykey" \
  -H "Authorization: Bearer $UPSTASH_REDIS_REST_TOKEN"

Multi-Command Pipeline

curl -s "$UPSTASH_REDIS_REST_URL/pipeline" \
  -H "Authorization: Bearer $UPSTASH_REDIS_REST_TOKEN" \
  -H "Content-Type: application/json" \
  -d '[
    ["SET", "key1", "val1"],
    ["SET", "key2", "val2"],
    ["MGET", "key1", "key2"]
  ]' | jq .

Managed Service Setup

Upstash (Recommended for serverless)

1. Sign up at upstash.com
2. Create a Redis database
3. Copy REST URL and REST Token from dashboard
4. Set UPSTASH_REDIS_REST_URL and UPSTASH_REDIS_REST_TOKEN

Redis Cloud

1. Sign up at redis.com/cloud
2. Create a database
3. Use the public endpoint as REDIS_URL: redis://default:password@host:port

AWS ElastiCache

• Use VPC endpoint: redis://host:6379
• Note: Must be in same VPC (no public access by default)

Self-Hosted

• REDIS_URL=redis://localhost:6379 or redis://:password@host:6379

Error Handling

Tips

• Use SCAN instead of KEYS in production — KEYS blocks the server
• Set TTL on cache keys — use EX to auto-expire keys and prevent memory bloat
• Use hashes for objects — more memory-efficient than serialized JSON strings
• Upstash REST for serverless — no persistent connection needed, HTTP-based
• Pipeline commands — batch multiple operations for better performance
• Use --no-auth-warning flag to suppress auth warnings: redis-cli --no-auth-warning -u "$REDIS_URL"