RabbitMQ Core Knowledge

Full Reference: See advanced.md for producer patterns (Node.js, Java, Python, Go), consumer patterns, security configuration, and high availability setup.

Deep Knowledge: Use mcp__documentation__fetch_docs with technology: rabbitmq for comprehensive documentation.

Quick Start (Docker)

services:
  rabbitmq:
    image: rabbitmq:3-management
    ports:
      - "5672:5672"   # AMQP
      - "15672:15672" # Management UI
    environment:
      - RABBITMQ_DEFAULT_USER=admin
      - RABBITMQ_DEFAULT_PASS=admin

Core Concepts

| Concept | Description | |---------|-------------| | Exchange | Routes messages to queues | | Queue | Buffer that stores messages | | Binding | Rule linking exchange to queue | | Routing Key | Message attribute for routing |

Architecture

Producer ──▶ Exchange ──binding──▶ Queue ──▶ Consumer
                │
                ├── direct   (exact routing key match)
                ├── topic    (pattern matching)
                ├── fanout   (broadcast to all)
                └── headers  (header-based routing)

Exchange Types

| Type | Routing | Use Case | |------|---------|----------| | direct | Exact key match | Task queues, RPC | | topic | Pattern (*.#) | Event routing | | fanout | Broadcast all | Notifications | | headers | Header match | Complex routing |

# Topic exchange patterns
order.*        → matches order.created, order.updated
order.#        → matches order.created, order.item.added
*.created      → matches order.created, user.created

Queue Configuration

| Argument | Description | |----------|-------------| | x-message-ttl | Message expiration (ms) | | x-max-length | Max queue size | | x-dead-letter-exchange | DLX for rejected messages | | x-dead-letter-routing-key | DLQ routing key | | x-queue-type | classic, quorum, stream |

When NOT to Use This Skill

• Event streaming with replay - Kafka provides persistent log
• Ultra-high throughput (>100k msg/s) - Kafka or Pulsar scale better
• AWS-native architecture - SQS integrates better
• Lightweight messaging - NATS has simpler operations
• JMS compliance required - ActiveMQ provides JMS API

Anti-Patterns

| Anti-Pattern | Why It's Bad | Solution | |--------------|--------------|----------| | No prefetch limit | Consumer overwhelmed | Set prefetch to 10-50 | | Classic queues in HA | Data loss on node failure | Use quorum queues | | No DLX configured | Poison messages loop forever | Configure dead letter exchange | | Automatic acks | Message loss on crash | Use manual acks | | No publisher confirms | Silent message loss | Enable confirms for critical messages |

Quick Troubleshooting

| Issue | Likely Cause | Fix | |-------|--------------|-----| | Messages piling up | Slow/dead consumer | Check consumer count and processing | | High memory usage | Too many unacked messages | Reduce prefetch, add consumers | | Messages not routed | Wrong routing key | Check exchange-queue bindings | | Duplicate messages | Consumer crashed before ack | Implement idempotent processing | | Publisher confirms timeout | Broker overloaded | Reduce publish rate |

Production Checklist

• [ ] TLS/SSL enabled
• [ ] Users with least privilege
• [ ] Virtual hosts for isolation
• [ ] Quorum queues for HA
• [ ] Dead letter exchanges configured
• [ ] Message TTL set
• [ ] Prefetch limits configured
• [ ] Publisher confirms enabled
• [ ] Monitoring dashboards
• [ ] Alerting configured

Reference Documentation

Available topics: basics, exchanges, queues, consumers, clustering, production