Staging Environment Setup with PM2¶

Complete guide for deploying the MMR SaaS Platform to a staging server using PM2 process manager (without Docker).

Table of Contents¶

Overview
Server Prerequisites
Installing Dependencies
Application Setup
PM2 Process Management
NGINX Configuration
Database Configuration
Security Hardening
Monitoring
Backup Strategies
Deployment Workflow
Troubleshooting

Overview¶

This guide covers deploying to a staging environment using: - PM2: Process manager for Node.js applications - NGINX: Reverse proxy and web server - MySQL: Database server - Redis: Caching and session storage - Let's Encrypt: Free SSL certificates

Target Environment: Ubuntu 22.04 LTS (also works on 20.04, Debian 11+)

Server Prerequisites¶

Minimum Specifications¶

Resource	Minimum	Recommended
CPU	2 vCPU	4 vCPU
RAM	4 GB	8 GB
Storage	40 GB SSD	80 GB SSD
Bandwidth	100 Mbps	1 Gbps

Required Access¶

Root or sudo access
SSH key authentication (recommended)
Firewall control (UFW or similar)
Domain name with DNS control

Supported OS¶

Ubuntu 22.04 LTS (recommended)
Ubuntu 20.04 LTS
Debian 11+

Installing Dependencies¶

1. Update System Packages¶

# Connect to server
ssh user@your-server-ip

# Update package lists
sudo apt update

# Upgrade installed packages
sudo apt upgrade -y

# Install essential tools
sudo apt install -y curl wget git build-essential

2. Install Node.js 18.x¶

# Add NodeSource repository
curl -fsSL https://deb.nodesource.com/setup_18.x | sudo -E bash -

# Install Node.js
sudo apt install -y nodejs

# Verify installation
node --version  # Should show v18.x.x
npm --version   # Should show 9.x.x or higher

3. Install PNPM¶

# Install PNPM globally
npm install -g pnpm

# Verify installation
pnpm --version  # Should show 8.x.x or higher

4. Install PM2¶

# Install PM2 globally
npm install -g pm2

# Verify installation
pm2 --version

# Setup PM2 startup script (runs on server reboot)
pm2 startup
# Follow the command it outputs (sudo env PATH=...)

# Save PM2 process list
pm2 save

5. Install MySQL 8.x¶

# Install MySQL Server
sudo apt install -y mysql-server

# Secure MySQL installation
sudo mysql_secure_installation

# Follow prompts:
# - Set root password
# - Remove anonymous users: Yes
# - Disallow root login remotely: Yes
# - Remove test database: Yes
# - Reload privilege tables: Yes

# Verify installation
sudo systemctl status mysql
mysql --version  # Should show 8.0.x

6. Install Redis 7.x¶

# Install Redis
sudo apt install -y redis-server

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

# Start Redis
sudo systemctl start redis-server

# Verify installation
redis-cli ping  # Should return "PONG"

7. Install NGINX¶

# Install NGINX
sudo apt install -y nginx

# Enable NGINX to start on boot
sudo systemctl enable nginx

# Start NGINX
sudo systemctl start nginx

# Verify installation
sudo systemctl status nginx
nginx -v  # Should show nginx version

# Test NGINX
curl http://localhost  # Should show NGINX welcome page

Application Setup¶

1. Create Application User¶

# Create user without login shell (security)
sudo useradd -r -s /bin/false mmr-app

# Or create user with bash (for debugging)
sudo useradd -m -s /bin/bash mmr-app

# Switch to application user
sudo su - mmr-app

2. Clone Repository¶

# Navigate to home directory
cd ~

# Clone repository (use HTTPS or SSH)
git clone <repository-url> mmr-saas
cd mmr-saas

# Checkout specific branch/tag
git checkout main  # or develop for staging

3. Install Dependencies¶

# Install all dependencies
pnpm install

# Verify installation
pnpm list --depth=0

4. Configure Environment Variables¶

Backend Environment¶

# Create .env file from example
cp apps/backend/.env.example apps/backend/.env

# Edit environment file
nano apps/backend/.env

Backend .env Configuration:

# Server Configuration
NODE_ENV=staging
PORT=3001
API_PREFIX=api

# Database
DB_HOST=localhost
DB_PORT=3306
DB_USERNAME=mmr_user
DB_PASSWORD=your-secure-database-password
DB_NAME=mmr_saas_staging
DB_SYNCHRONIZE=false  # Always false in production/staging

# Redis
REDIS_HOST=localhost
REDIS_PORT=6379
REDIS_PASSWORD=  # Leave empty if no password

# JWT Secrets (generate strong secrets)
# Generate with: node -e "console.log(require('crypto').randomBytes(64).toString('hex'))"
JWT_SECRET=your-super-secret-jwt-key-64-characters-or-more
JWT_EXPIRES_IN=15m
JWT_REFRESH_SECRET=your-super-secret-refresh-key-64-characters-or-more
JWT_REFRESH_EXPIRY=7d

# CORS
CORS_ORIGIN=https://staging.yourdomain.com

# Rate Limiting
RATE_LIMIT_LOGIN_ATTEMPTS=5
RATE_LIMIT_LOCKOUT_MINUTES=15

# Logging
LOG_LEVEL=info  # debug | info | warn | error

Frontend Environment¶

# Create .env.local file
cp apps/web/.env.example apps/web/.env.local

# Edit environment file
nano apps/web/.env.local

Frontend .env.local Configuration:

# Backend API URL
NEXT_PUBLIC_API_URL=https://api.staging.yourdomain.com

# Environment
NEXT_PUBLIC_ENV=staging

# Analytics (optional)
NEXT_PUBLIC_GA_ID=  # Google Analytics ID

5. Setup Database¶

# Login to MySQL
mysql -u root -p

# Create database
CREATE DATABASE mmr_saas_staging CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;

# Create user with strong password
CREATE USER 'mmr_user'@'localhost' IDENTIFIED BY 'your-secure-database-password';

# Grant privileges
GRANT ALL PRIVILEGES ON mmr_saas_staging.* TO 'mmr_user'@'localhost';
FLUSH PRIVILEGES;

# Exit MySQL
EXIT;

# Test connection
mysql -u mmr_user -p mmr_saas_staging

6. Run Database Migrations¶

# Navigate to project directory
cd ~/mmr-saas

# Run migrations
pnpm db:migrate

# Verify migrations
pnpm migration:show

# (Optional) Seed test data for staging
pnpm db:seed

7. Build Applications¶

# Build both frontend and backend
pnpm build

# Or build separately
pnpm build:back  # Backend only
pnpm build:web   # Frontend only

# Verify build output
ls -la apps/backend/dist
ls -la apps/web/.next

PM2 Process Management¶

1. Create PM2 Ecosystem Config¶

Create ecosystem.config.js in project root:

nano ~/mmr-saas/ecosystem.config.js

ecosystem.config.js:

module.exports = {
  apps: [
    {
      name: 'mmr-backend',
      cwd: '/home/mmr-app/mmr-saas/apps/backend',
      script: 'dist/main.js',
      instances: 2,  // Number of instances (CPU cores)
      exec_mode: 'cluster',
      env: {
        NODE_ENV: 'staging',
        PORT: 3001,
      },
      error_file: '/home/mmr-app/logs/backend-error.log',
      out_file: '/home/mmr-app/logs/backend-out.log',
      log_date_format: 'YYYY-MM-DD HH:mm:ss Z',
      merge_logs: true,
      autorestart: true,
      max_memory_restart: '1G',
      watch: false,
    },
    {
      name: 'mmr-frontend',
      cwd: '/home/mmr-app/mmr-saas/apps/web',
      script: 'node_modules/next/dist/bin/next',
      args: 'start -p 3000',
      instances: 1,
      exec_mode: 'cluster',
      env: {
        NODE_ENV: 'production',
        PORT: 3000,
      },
      error_file: '/home/mmr-app/logs/frontend-error.log',
      out_file: '/home/mmr-app/logs/frontend-out.log',
      log_date_format: 'YYYY-MM-DD HH:mm:ss Z',
      merge_logs: true,
      autorestart: true,
      max_memory_restart: '1G',
      watch: false,
    },
  ],
};

2. Create Log Directory¶

# Create logs directory
mkdir -p ~/logs

# Set permissions
chmod 755 ~/logs

3. Start Applications with PM2¶

# Start all applications
pm2 start ecosystem.config.js

# Or start individually
pm2 start ecosystem.config.js --only mmr-backend
pm2 start ecosystem.config.js --only mmr-frontend

# View running processes
pm2 list

# View logs
pm2 logs

# View logs for specific app
pm2 logs mmr-backend
pm2 logs mmr-frontend --lines 100

# Monitor processes
pm2 monit

4. PM2 Commands Reference¶

# Process Management
pm2 start ecosystem.config.js     # Start all apps
pm2 stop all                       # Stop all apps
pm2 restart all                    # Restart all apps
pm2 reload all                     # Graceful reload (zero downtime)
pm2 delete all                     # Delete all apps

# Individual App Control
pm2 stop mmr-backend
pm2 restart mmr-backend
pm2 reload mmr-backend

# Logs
pm2 logs                           # All logs (live tail)
pm2 logs mmr-backend --lines 200   # Last 200 lines
pm2 logs --err                     # Error logs only
pm2 flush                          # Clear logs

# Monitoring
pm2 monit                          # Real-time monitoring
pm2 status                         # Process status
pm2 describe mmr-backend           # Detailed info

# Startup
pm2 startup                        # Generate startup script
pm2 save                           # Save current process list
pm2 resurrect                      # Restore saved processes

# Updates
pm2 update                         # Update PM2 daemon

NGINX Configuration¶

1. Create NGINX Configuration File¶

# Create new site configuration
sudo nano /etc/nginx/sites-available/mmr-saas

NGINX Configuration:

# Upstream definitions
upstream mmr_backend {
    least_conn;  # Load balancing method
    server localhost:3001;
    # Add more backend instances if using multiple servers
    # server localhost:3002;
}

upstream mmr_frontend {
    server localhost:3000;
}

# Redirect HTTP to HTTPS (will be uncommented after SSL setup)
# server {
#     listen 80;
#     listen [::]:80;
#     server_name staging.yourdomain.com api.staging.yourdomain.com;
#     return 301 https://$server_name$request_uri;
# }

# Frontend Server (HTTPS)
server {
    listen 80;
    # listen 443 ssl http2;  # Uncomment after SSL setup
    # listen [::]:443 ssl http2;
    server_name staging.yourdomain.com;

    # SSL Configuration (uncomment after certbot)
    # ssl_certificate /etc/letsencrypt/live/staging.yourdomain.com/fullchain.pem;
    # ssl_certificate_key /etc/letsencrypt/live/staging.yourdomain.com/privkey.pem;
    # include /etc/letsencrypt/options-ssl-nginx.conf;
    # ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem;

    # Security Headers
    add_header X-Frame-Options "SAMEORIGIN" always;
    add_header X-Content-Type-Options "nosniff" always;
    add_header X-XSS-Protection "1; mode=block" always;
    add_header Referrer-Policy "strict-origin-when-cross-origin" always;

    # Logging
    access_log /var/log/nginx/mmr-frontend-access.log;
    error_log /var/log/nginx/mmr-frontend-error.log;

    # Gzip Compression
    gzip on;
    gzip_vary on;
    gzip_min_length 1024;
    gzip_types text/plain text/css text/xml text/javascript application/json application/javascript application/xml+rss;

    # Proxy to Next.js
    location / {
        proxy_pass http://mmr_frontend;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection 'upgrade';
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
        proxy_cache_bypass $http_upgrade;
        proxy_read_timeout 60s;
        proxy_connect_timeout 60s;
    }

    # Static files caching
    location /_next/static {
        proxy_pass http://mmr_frontend;
        proxy_cache_valid 200 60m;
        add_header Cache-Control "public, max-age=3600, immutable";
    }
}

# Backend API Server (HTTPS)
server {
    listen 80;
    # listen 443 ssl http2;  # Uncomment after SSL setup
    # listen [::]:443 ssl http2;
    server_name api.staging.yourdomain.com;

    # SSL Configuration (uncomment after certbot)
    # ssl_certificate /etc/letsencrypt/live/api.staging.yourdomain.com/fullchain.pem;
    # ssl_certificate_key /etc/letsencrypt/live/api.staging.yourdomain.com/privkey.pem;
    # include /etc/letsencrypt/options-ssl-nginx.conf;
    # ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem;

    # Security Headers
    add_header X-Frame-Options "DENY" always;
    add_header X-Content-Type-Options "nosniff" always;
    add_header X-XSS-Protection "1; mode=block" always;

    # Logging
    access_log /var/log/nginx/mmr-backend-access.log;
    error_log /var/log/nginx/mmr-backend-error.log;

    # Gzip Compression
    gzip on;
    gzip_vary on;
    gzip_types application/json text/plain;

    # Proxy to NestJS Backend
    location / {
        proxy_pass http://mmr_backend;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection 'upgrade';
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
        proxy_cache_bypass $http_upgrade;
        proxy_read_timeout 300s;
        proxy_connect_timeout 300s;
        proxy_send_timeout 300s;

        # CORS headers (if needed)
        # add_header 'Access-Control-Allow-Origin' 'https://staging.yourdomain.com' always;
        # add_header 'Access-Control-Allow-Credentials' 'true' always;
        # add_header 'Access-Control-Allow-Methods' 'GET, POST, PUT, DELETE, OPTIONS' always;
        # add_header 'Access-Control-Allow-Headers' 'Authorization, Content-Type' always;
    }

    # Health check endpoint (public)
    location /health {
        proxy_pass http://mmr_backend/api/health;
        access_log off;
    }
}

2. Enable Site and Test Configuration¶

# Create symbolic link to enable site
sudo ln -s /etc/nginx/sites-available/mmr-saas /etc/nginx/sites-enabled/

# Remove default site (optional)
sudo rm /etc/nginx/sites-enabled/default

# Test NGINX configuration
sudo nginx -t

# If test passes, reload NGINX
sudo systemctl reload nginx

3. Configure DNS¶

Point your domain to the server:

A Record:  staging.yourdomain.com         → your-server-ip
A Record:  api.staging.yourdomain.com     → your-server-ip

Wait for DNS propagation (5-30 minutes).

4. Install SSL Certificate (Let's Encrypt)¶

# Install Certbot
sudo apt install -y certbot python3-certbot-nginx

# Obtain SSL certificates
sudo certbot --nginx -d staging.yourdomain.com -d api.staging.yourdomain.com

# Follow prompts:
# - Enter email address
# - Agree to terms
# - Choose: Redirect HTTP to HTTPS (option 2)

# Certbot will automatically update NGINX config

# Test auto-renewal
sudo certbot renew --dry-run

# Auto-renewal is already configured via systemd timer
sudo systemctl status certbot.timer

5. Verify SSL¶

# Test HTTPS
curl https://staging.yourdomain.com
curl https://api.staging.yourdomain.com/api/health

# Check SSL certificate
openssl s_client -connect staging.yourdomain.com:443 -showcerts

Database Configuration¶

1. MySQL Performance Tuning¶

# Edit MySQL config
sudo nano /etc/mysql/mysql.conf.d/mysqld.cnf

Add/Update:

[mysqld]
# Performance tuning
max_connections = 200
innodb_buffer_pool_size = 2G  # 50-70% of RAM
innodb_log_file_size = 256M
innodb_flush_log_at_trx_commit = 2
query_cache_size = 0
query_cache_type = 0

# Logging
slow_query_log = 1
slow_query_log_file = /var/log/mysql/slow-query.log
long_query_time = 2

# Restart MySQL
sudo systemctl restart mysql

2. Database Backups¶

Create backup script:

nano ~/backup-db.sh

backup-db.sh:

#!/bin/bash

BACKUP_DIR="/home/mmr-app/backups/mysql"
DATE=$(date +%Y%m%d_%H%M%S)
DB_NAME="mmr_saas_staging"
DB_USER="mmr_user"
DB_PASS="your-secure-database-password"

# Create backup directory
mkdir -p $BACKUP_DIR

# Dump database
mysqldump -u $DB_USER -p$DB_PASS $DB_NAME | gzip > $BACKUP_DIR/mmr_saas_$DATE.sql.gz

# Keep only last 7 days of backups
find $BACKUP_DIR -name "*.sql.gz" -type f -mtime +7 -delete

echo "Backup completed: $BACKUP_DIR/mmr_saas_$DATE.sql.gz"

# Make executable
chmod +x ~/backup-db.sh

# Test backup
./backup-db.sh

# Schedule daily backups (cron)
crontab -e

# Add line:
0 2 * * * /home/mmr-app/backup-db.sh >> /home/mmr-app/logs/backup.log 2>&1

Security Hardening¶

1. Firewall (UFW)¶

# Install UFW
sudo apt install -y ufw

# Allow SSH (IMPORTANT: Do this first!)
sudo ufw allow 22/tcp

# Allow HTTP and HTTPS
sudo ufw allow 80/tcp
sudo ufw allow 443/tcp

# Enable firewall
sudo ufw enable

# Check status
sudo ufw status verbose

# Application will be accessible only via NGINX (ports 80/443)
# PM2 apps (3000, 3001) are not exposed directly

2. Fail2Ban (Brute Force Protection)¶

# Install Fail2Ban
sudo apt install -y fail2ban

# Create local configuration
sudo cp /etc/fail2ban/jail.conf /etc/fail2ban/jail.local

# Edit configuration
sudo nano /etc/fail2ban/jail.local

Add NGINX protection:

[nginx-http-auth]
enabled = true

[nginx-limit-req]
enabled = true
port = http,https
logpath = /var/log/nginx/*error.log

[nginx-botsearch]
enabled = true
port = http,https
logpath = /var/log/nginx/*access.log

# Restart Fail2Ban
sudo systemctl restart fail2ban

# Check status
sudo fail2ban-client status

3. SSH Hardening¶

# Edit SSH config
sudo nano /etc/ssh/sshd_config

Recommended changes:

# Disable root login
PermitRootLogin no

# Use SSH keys only (disable password auth)
PasswordAuthentication no
ChallengeResponseAuthentication no

# Change default port (optional)
Port 2222

# Allow specific users only
AllowUsers mmr-app yourusername

# Restart SSH
sudo systemctl restart sshd

# IMPORTANT: Test new SSH connection in another terminal before closing current session!

4. Automatic Security Updates¶

# Install unattended-upgrades
sudo apt install -y unattended-upgrades

# Enable automatic updates
sudo dpkg-reconfigure -plow unattended-upgrades

# Select "Yes" to enable

Monitoring¶

1. PM2 Monitoring¶

# Real-time monitoring
pm2 monit

# Process status
pm2 status

# Detailed app info
pm2 describe mmr-backend

# System info
pm2 info

# View logs
pm2 logs --lines 100

2. Application Logs¶

# Backend logs
tail -f /home/mmr-app/logs/backend-out.log
tail -f /home/mmr-app/logs/backend-error.log

# Frontend logs
tail -f /home/mmr-app/logs/frontend-out.log

# NGINX logs
sudo tail -f /var/log/nginx/mmr-backend-access.log
sudo tail -f /var/log/nginx/mmr-frontend-error.log

3. System Monitoring¶

# Install htop (better than top)
sudo apt install -y htop

# Monitor system resources
htop

# Disk usage
df -h

# Memory usage
free -h

# Process tree
pstree -p

# Network connections
netstat -tulpn

# Or use ss
ss -tulpn

4. Health Checks¶

Create health check script:

nano ~/health-check.sh

health-check.sh:

#!/bin/bash

# Check backend health
BACKEND=$(curl -s -o /dev/null -w "%{http_code}" http://localhost:3001/api/health)
if [ "$BACKEND" -eq 200 ]; then
    echo "Backend: OK"
else
    echo "Backend: FAILED (HTTP $BACKEND)"
    # Restart backend
    pm2 restart mmr-backend
fi

# Check frontend
FRONTEND=$(curl -s -o /dev/null -w "%{http_code}" http://localhost:3000)
if [ "$FRONTEND" -eq 200 ] || [ "$FRONTEND" -eq 304 ]; then
    echo "Frontend: OK"
else
    echo "Frontend: FAILED (HTTP $FRONTEND)"
    # Restart frontend
    pm2 restart mmr-frontend
fi

# Check MySQL
if mysqladmin ping -u mmr_user -pyour-password &> /dev/null; then
    echo "MySQL: OK"
else
    echo "MySQL: FAILED"
    sudo systemctl restart mysql
fi

# Check Redis
if redis-cli ping &> /dev/null; then
    echo "Redis: OK"
else
    echo "Redis: FAILED"
    sudo systemctl restart redis-server
fi

# Make executable
chmod +x ~/health-check.sh

# Schedule every 5 minutes (cron)
crontab -e

# Add line:
*/5 * * * * /home/mmr-app/health-check.sh >> /home/mmr-app/logs/health.log 2>&1

Backup Strategies¶

1. Database Backups¶

Already configured in Database Configuration section.

2. Application File Backups¶

# Create backup directory
mkdir -p ~/backups/files

# Backup entire application (excluding node_modules)
tar --exclude='node_modules' --exclude='.git' \
    -czf ~/backups/files/mmr-saas-$(date +%Y%m%d).tar.gz \
    ~/mmr-saas

# Automate (add to cron)
crontab -e

# Add line (daily at 3 AM):
0 3 * * * tar --exclude='node_modules' --exclude='.git' -czf ~/backups/files/mmr-saas-$(date +\%Y\%m\%d).tar.gz ~/mmr-saas

3. Off-Site Backups¶

# Install rclone for cloud backups
curl https://rclone.org/install.sh | sudo bash

# Configure rclone (AWS S3, Google Drive, etc.)
rclone config

# Sync backups to cloud
rclone sync ~/backups remote:mmr-backups

# Automate (add to cron)
0 4 * * * rclone sync ~/backups remote:mmr-backups

Deployment Workflow¶

Deploying Updates¶

# 1. SSH to server
ssh mmr-app@your-server-ip

# 2. Navigate to project
cd ~/mmr-saas

# 3. Pull latest code
git pull origin main  # or develop for staging

# 4. Install new dependencies (if any)
pnpm install

# 5. Run database migrations (if any)
pnpm db:migrate

# 6. Build applications
pnpm build

# 7. Reload PM2 processes (zero downtime)
pm2 reload all

# 8. Verify deployment
curl http://localhost:3001/api/health
curl http://localhost:3000

# 9. Check logs
pm2 logs --lines 50

Rollback Procedure¶

# 1. Find previous commit
git log --oneline -5

# 2. Revert to previous commit
git reset --hard <previous-commit-hash>

# 3. Rebuild
pnpm build

# 4. Reload PM2
pm2 reload all

# Or use git revert for safer rollback
git revert <bad-commit-hash>
pnpm build
pm2 reload all

Troubleshooting¶

PM2 Process Not Starting¶

# Check PM2 logs
pm2 logs mmr-backend --err --lines 100

# Check if port is in use
sudo lsof -i :3001
sudo lsof -i :3000

# Kill process using port
sudo kill -9 <PID>

# Restart PM2
pm2 delete all
pm2 start ecosystem.config.js

Database Connection Errors¶

# Check MySQL is running
sudo systemctl status mysql

# Check connection
mysql -u mmr_user -p mmr_saas_staging

# Check credentials in .env
cat apps/backend/.env | grep DB_

# Check MySQL logs
sudo tail -f /var/log/mysql/error.log

NGINX Configuration Errors¶

# Test configuration
sudo nginx -t

# Check syntax errors
sudo nginx -T

# Reload NGINX
sudo systemctl reload nginx

# Check NGINX logs
sudo tail -f /var/log/nginx/error.log

SSL Certificate Issues¶

# Test certificate renewal
sudo certbot renew --dry-run

# Force renewal
sudo certbot renew --force-renewal

# Check certificate expiry
sudo certbot certificates

# NGINX reload after renewal
sudo systemctl reload nginx

Out of Memory Errors¶

# Check memory usage
free -h

# Check PM2 memory limits
pm2 list

# Adjust PM2 memory limit in ecosystem.config.js
max_memory_restart: '2G'  # Increase from 1G

# Add swap space (if needed)
sudo fallocate -l 4G /swapfile
sudo chmod 600 /swapfile
sudo mkswap /swapfile
sudo swapon /swapfile

# Make swap permanent
echo '/swapfile none swap sw 0 0' | sudo tee -a /etc/fstab

High CPU Usage¶

# Check processes
htop

# Check PM2 CPU usage
pm2 monit

# Reduce PM2 instances
# Edit ecosystem.config.js: instances: 1

# Optimize Node.js
# Add to ecosystem.config.js:
node_args: '--max-old-space-size=2048'

Redis Connection Errors¶

# Check Redis is running
sudo systemctl status redis-server

# Test connection
redis-cli ping

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

# Restart Redis
sudo systemctl restart redis-server

Quick Reference¶

Common PM2 Commands¶

pm2 start ecosystem.config.js     # Start all apps
pm2 reload all                     # Zero-downtime reload
pm2 restart all                    # Hard restart
pm2 stop all                       # Stop all apps
pm2 logs                           # View logs
pm2 monit                          # Monitor
pm2 save                           # Save process list

Common NGINX Commands¶

sudo nginx -t                      # Test config
sudo systemctl reload nginx        # Reload config
sudo systemctl restart nginx       # Restart NGINX
sudo tail -f /var/log/nginx/error.log  # View logs

Common MySQL Commands¶

sudo systemctl status mysql        # Check status
mysql -u mmr_user -p              # Login
sudo tail -f /var/log/mysql/error.log  # View logs

Version: 2.0.0 | Last Updated: 2026-06-20