PM2 Process Layout

Overview

wiki/entities/b2bpaper uses PM2 as its process manager on the Contabo VPS. PM2 handles process startup, restart on crash, log management, and monitoring. All backend processes are managed through PM2 rather than systemd or Docker.

Managed Processes

marketplace-api

• What it runs: Gunicorn serving the Django application
• Port: 8910 (bound to 127.0.0.1)
• Proxied by: Nginx at https://b2bpaper.xdvu.com/mvp/ (see wiki/concepts/nginx-mvp-routing)
• Role: Serves all HTTP requests -- API endpoints, admin interface, static files (via Nginx)

celery-worker

• What it runs: Celery worker process consuming tasks from Redis
• Role: Executes async tasks including:
  • Email ingestion (parsing incoming mill emails)
  • Matching algorithm execution
  • Newsletter generation and sending
  • Container assembly calculations
• Broker: Redis (local)

celery-beat

• What it runs: Celery Beat scheduler
• Role: Triggers periodic tasks on a schedule:
  • Weekly newsletter generation
  • Exclusivity window expiry checks
  • Data cleanup and maintenance tasks
• Broker: Redis (local)

Infrastructure Dependencies

PM2
 ├── marketplace-api (gunicorn) → port 8910 → Nginx → public
 ├── celery-worker → Redis → task execution
 └── celery-beat → Redis → scheduled triggers
                     ↓
                PostgreSQL (db: b2bpaper)

All three processes depend on:

• PostgreSQL -- the b2bpaper database (credentials in backend/.env)
• Redis -- message broker for Celery task queue

Management Commands

Common PM2 operations:

• pm2 status -- check all process statuses
• pm2 restart marketplace-api -- restart the Django server
• pm2 logs marketplace-api -- view recent logs
• pm2 restart all -- restart everything

Key Rules

• Never run python manage.py runserver in production -- always use PM2-managed gunicorn
• Never run ng serve -- the frontend is built and served as static files
• Always check PM2 status after deployment changes
• 12-factor app -- all configuration via environment variables in backend/.env

Sources

• raw/notes/techContext -- PM2 process name, port configuration, and infrastructure details

Related

• wiki/concepts/nginx-mvp-routing -- how Nginx proxies to marketplace-api
• wiki/concepts/deployment-urls -- the public URLs that map to these processes
• wiki/concepts/django-app-layout -- the Django app that marketplace-api serves
• wiki/concepts/eight-core-actions -- the actions that celery-worker executes
• wiki/entities/b2bpaper -- the platform these processes power