What is RabbitMQ?

• Open-source message broker
• Acts as a middleman between services to send/receive messages
• Supports multiple messaging protocols, mainly AMQP
• Ensures asynchronous communication, reliability, and message persistence

What is AMQP?

• Advanced Message Queuing Protocol
• Standard protocol for messaging systems
• Defines how messages are formatted, sent, stored, and received
• Key components:
  • Producer → Sends messages
  • Exchange → Routes messages
  • Queue → Stores messages
  • Consumer → Receives messages

Four Exchange Types of AMQP

1. Direct Exchange
   • Routes messages to queues with matching routing keys
   • Example: "order.created" → goes only to order processing queue
2. Fanout Exchange
   • Sends messages to all bound queues, ignoring routing keys
   • Example: Sending a system-wide notification
3. Topic Exchange
   • Routes messages based on pattern matching in routing keys
   • Example: "order.*" matches "order.created", "order.cancelled"
4. Headers Exchange
   • Routes messages based on header attributes instead of routing keys
   • Example: Send message only if "type=pdf"

RabbitMQ Setup

Deploy RabbitMQ with Docker Compose