Publisher Subscriber Model
Quick Reference: Async Processing
Quick Reference
| Pattern | Coupling | Use Case |
|---|---|---|
| Pub/Sub | Loose | Event-driven systems |
| Point-to-Point | Tight | Task queues |
| Request-Reply | Tight | RPC-like |
Clear Definition
Pub/Sub (Publisher-Subscriber) is a messaging pattern where publishers send messages without knowing subscribers. Subscribers express interest in message types and receive relevant messages. This decouples components and enables scalable, event-driven architectures.
š” Key Insight: Pub/Sub enables loose coupling and horizontal scaling by decoupling message producers from consumers.
Core Concepts
Components
- Publisher: Produces messages
- Subscriber: Consumes messages
- Broker: Routes messages
- Topic/Channel: Message category
Benefits
- Decoupling: Publishers don't know subscribers
- Scalability: Add subscribers easily
- Flexibility: Multiple subscribers per topic
- Resilience: Failed subscriber doesn't affect others
Use Cases
- Event-Driven Systems: Microservices communication
- Real-time Updates: Notifications, feeds
- Log Aggregation: Centralized logging
- CQRS: Command Query Responsibility Segregation
Best Practices
- Design Topics: Organize by domain/event type
- Idempotency: Handle duplicate messages
- Ordering: Consider message ordering needs
- Monitoring: Track subscription health
Quick Reference Summary
Pub/Sub: Decoupled messaging pattern for event-driven systems.
Key Benefit: Loose coupling and horizontal scalability.
Use For: Event-driven architectures, real-time updates, microservices.
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