Redis Setup

Vercel For Frontend uses Redis to manage the build queue between the upload service and deploy service. The upload service pushes project IDs to the queue, and the deploy service pulls them for processing.

How Redis is Used

The platform uses Redis for asynchronous job processing:

Upload Service (upload-service/src/utils/buildQueue.ts:11): Pushes project IDs to the build-queue using LPUSH
Deploy Service (deploy-service/src/server.ts:13): Blocks and waits for new items using BLPOP

Redis acts as a reliable message broker, ensuring builds are processed in order and no projects are lost during high load.

Installation

Install via Homebrew

brew install redis

Start Redis Server

brew services start redis

Or run Redis in the foreground:

redis-server

Verify Installation

redis-cli ping

Expected output: PONG

Install Redis

sudo apt update
sudo apt install redis-server -y

Configure Redis

Edit the Redis configuration:

sudo nano /etc/redis/redis.conf

Find and update:

# Change from 'supervised no' to:
supervised systemd

Save and exit (Ctrl+X, Y, Enter).

Start Redis Service

sudo systemctl start redis-server
sudo systemctl enable redis-server

Check Status

sudo systemctl status redis-server

Should show active (running).

Verify Installation

redis-cli ping

Expected output: PONG

Install Redis

sudo yum install redis -y

Or for newer systems:

sudo dnf install redis -y

Start Redis Service

sudo systemctl start redis
sudo systemctl enable redis

Configure Firewall (if needed)

sudo firewall-cmd --permanent --add-port=6379/tcp
sudo firewall-cmd --reload

Verify Installation

redis-cli ping

Expected output: PONG

Download Redis

Windows doesn’t have official Redis support, but you can use:

WSL2 (Recommended): Install Redis in Ubuntu on WSL
Redis for Windows: Download from Memurai (Redis-compatible)
Docker: Run Redis in a container (see Docker tab)

Install via WSL2

# In WSL2 Ubuntu terminal
sudo apt update
sudo apt install redis-server -y
sudo service redis-server start

Verify Installation

redis-cli ping

Expected output: PONG

Pull Redis Image

docker pull redis:alpine

Run Redis Container

docker run -d \
  --name redis \
  -p 6379:6379 \
  redis:alpine

With persistence:

docker run -d \
  --name redis \
  -p 6379:6379 \
  -v redis-data:/data \
  redis:alpine redis-server --appendonly yes

Verify Installation

docker exec -it redis redis-cli ping

Expected output: PONG

Add Redis to your docker-compose.yml:

docker-compose.yml

version: '3.8'

services:
  redis:
    image: redis:alpine
    ports:
      - "6379:6379"
    volumes:
      - redis-data:/data
    command: redis-server --appendonly yes
    healthcheck:
      test: ["CMD", "redis-cli", "ping"]
      interval: 5s
      timeout: 3s
      retries: 5

  upload-service:
    depends_on:
      - redis
    environment:
      - REDIS_URL=redis://redis:6379

  deploy-service:
    depends_on:
      - redis
    environment:
      - REDIS_URL=redis://redis:6379

volumes:
  redis-data:

Start services:

docker-compose up -d

Configuration

Default Configuration

The application uses default Redis connection settings:

// Default connection (localhost:6379)
const client = createClient()

This connects to:

Host: localhost (127.0.0.1)
Port: 6379
Database: 0
No authentication

Custom Configuration

If your Redis runs on a different host or port, update the connection:

const client = createClient({
  url: 'redis://username:password@hostname:6379'
})

If you modify connection settings, update both upload-service/src/utils/buildQueue.ts:3 and deploy-service/src/server.ts:5.

Production Configuration

For production deployments, configure Redis with:

redis.conf

# Bind to specific interface (or remove for all interfaces)
bind 127.0.0.1

# Require password
requirepass your-strong-password-here

# Enable persistence
appendonly yes
appendfsync everysec

# Set max memory
maxmemory 256mb
maxmemory-policy allkeys-lru

# Enable logging
loglevel notice
logfile /var/log/redis/redis-server.log

Restart Redis after changes:

sudo systemctl restart redis-server

Testing the Connection

Test Basic Connection

redis-cli ping

Expected: PONG

Test Queue Operations

Simulate the upload service pushing to queue:

redis-cli LPUSH build-queue "test-project-123"

Check queue length:

redis-cli LLEN build-queue

Simulate deploy service pulling from queue:

redis-cli BLPOP build-queue 5

Should return: 1) "build-queue" 2) "test-project-123"

Monitor Real-Time Activity

Watch Redis commands in real-time:

redis-cli MONITOR

Keep this running while your services operate to see queue activity.

Test from Node.js

Create a test script test-redis.js:

test-redis.js

import { createClient } from 'redis';

const client = createClient();

client.on('error', (err) => {
  console.error('Redis error:', err);
  process.exit(1);
});

client.on('connect', () => {
  console.log('✓ Connected to Redis');
});

await client.connect();

// Test push
await client.lPush('test-queue', 'test-value');
console.log('✓ Pushed to queue');

// Test pop
const value = await client.blPop('test-queue', 5);
console.log('✓ Popped from queue:', value);

await client.disconnect();
console.log('✓ All tests passed!');

Run with Bun:

bun test-redis.js

Monitoring and Management

Check Queue Status

# View queue length
redis-cli LLEN build-queue

# View queue contents without removing items
redis-cli LRANGE build-queue 0 -1

# View memory usage
redis-cli INFO memory

# View connected clients
redis-cli CLIENT LIST

Clear Queue

This will delete all pending builds. Use with caution!

redis-cli DEL build-queue

Backup and Restore

RDB Snapshot
AOF (Append-Only File)

# Trigger immediate save
redis-cli SAVE

# Background save
redis-cli BGSAVE

# Copy snapshot
cp /var/lib/redis/dump.rdb /backup/dump.rdb

# Restore (stop Redis first)
sudo systemctl stop redis-server
cp /backup/dump.rdb /var/lib/redis/dump.rdb
sudo systemctl start redis-server

# Enable AOF in redis.conf
appendonly yes

# Trigger rewrite
redis-cli BGREWRITEAOF

# Backup AOF file
cp /var/lib/redis/appendonly.aof /backup/appendonly.aof

Troubleshooting

Connection Refused

Error: Error: connect ECONNREFUSED 127.0.0.1:6379Solutions:

Check if Redis is running: redis-cli ping
Start Redis: sudo systemctl start redis-server
Check Redis logs: sudo tail -f /var/log/redis/redis-server.log
Verify port: sudo lsof -i :6379

Authentication Failed

Error: NOAUTH Authentication requiredSolutions:

Set password in connection:

const client = createClient({
  password: 'your-password'
})

Or disable auth in redis.conf (development only):
```
# requirepass your-password
```

Queue Not Processing

Symptoms: Items stay in queue, builds don’t startSolutions:

Check deploy service is running and connected
Verify queue has items: redis-cli LLEN build-queue
Check for errors in deploy service logs
Ensure BLPOP timeout is set correctly (0 = block forever)

Memory Issues

Error: OOM command not allowed when used memory > 'maxmemory'Solutions:

Increase max memory in redis.conf:
```
maxmemory 512mb
```
Set eviction policy:
```
maxmemory-policy allkeys-lru
```
Clear old data: redis-cli FLUSHDB

Redis Crashed

Symptoms: Service stops unexpectedlySolutions:

Check system logs: sudo journalctl -u redis-server -n 100
Verify disk space: df -h
Check Redis logs: /var/log/redis/redis-server.log
Increase system limits in /etc/systemd/system/redis.service:
```
[Service]
LimitNOFILE=65535
```

Security Best Practices

Enable Authentication

redis.conf

requirepass your-strong-password

Update connection:

createClient({ password: 'your-strong-password' })

Bind to Localhost

redis.conf

bind 127.0.0.1 ::1

Only allow local connections unless needed.

Rename Dangerous Commands

redis.conf

rename-command FLUSHDB ""
rename-command FLUSHALL ""
rename-command CONFIG "CONFIG-SECRET-NAME"

Use TLS Encryption

redis.conf

tls-port 6380
tls-cert-file /path/to/redis.crt
tls-key-file /path/to/redis.key
tls-ca-cert-file /path/to/ca.crt

Redis Cloud Alternatives

For production, consider managed Redis services:

AWS ElastiCache: Fully managed Redis on AWS
Redis Cloud: Official cloud offering from Redis Labs
DigitalOcean Managed Redis: Simple, affordable option
Azure Cache for Redis: Integrated with Azure services
Google Cloud Memorystore: Redis on Google Cloud

Update the connection URL in your services to point to the managed Redis endpoint.

Get Started

Core Features

Configuration

Guides

How Redis is Used

Installation

Configuration

Default Configuration

Custom Configuration

Production Configuration

Testing the Connection

Monitoring and Management

Check Queue Status

Clear Queue

Backup and Restore

Troubleshooting

Security Best Practices

Enable Authentication

Bind to Localhost

Rename Dangerous Commands

Use TLS Encryption

Redis Cloud Alternatives

Next Steps

Docker Setup

Environment Variables

Build docs developers (and LLMs) love

Get Started

Core Features

Configuration

Guides

​How Redis is Used

​Installation

​Configuration

​Default Configuration

​Custom Configuration

​Production Configuration

​Testing the Connection

​Monitoring and Management

​Check Queue Status

​Clear Queue

​Backup and Restore

​Troubleshooting

​Security Best Practices

Enable Authentication

Bind to Localhost

Rename Dangerous Commands

Use TLS Encryption

​Redis Cloud Alternatives

​Next Steps

Docker Setup

Environment Variables

Build docs developers (and LLMs) love

How Redis is Used

Installation

Configuration

Default Configuration

Custom Configuration

Production Configuration

Testing the Connection

Monitoring and Management

Check Queue Status

Clear Queue

Backup and Restore

Troubleshooting

Security Best Practices

Redis Cloud Alternatives

Next Steps