Chapter 7: Asynchronous Messaging & Pub/Sub Systems

Decoupling services through messages: queues vs streams, pub/sub, delivery guarantees, backpressure, dead letter queues, and fast data propagation.

• Message Queues vs Event Streams (RabbitMQ, Apache Kafka, Apache Pulsar)
• Publish-Subscribe (Pub/Sub) Architecture Mechanics & Fan-Out Design Patterns
• Message Delivery Guarantees: At-Most-Once, At-Least-Once, and Exactly-Once (Idempotency Patterns)
• Backpressure, Dead Letter Queues (DLQ), and Event Replay Frameworks
• Fast Data Propagation Mechanics: Gossip Protocols, Epidemic Dissemination, Anti-Entropy Mechanisms, Overlay Networks, and Low-Latency Broadcast Trees
• Chapter 7 References