Pub/Sub (Publish-Subscribe)
A messaging pattern where senders (publishers) send messages to topics without knowledge of receivers (subscribers), who receive messages by subscribing to topics.
In-Depth Explanation
Publish-subscribe (pub/sub) is a messaging pattern that decouples message senders from receivers. Publishers send messages to topics, and subscribers receive messages from topics they've subscribed to.
Pub/sub concepts:
- Publisher: Sends messages to a topic
- Subscriber: Receives messages from topics
- Topic: Named channel for messages
- Message: Data payload published to a topic
- Subscription: Subscriber's connection to a topic
Key characteristics:
- One-to-many messaging
- Publishers don't know about subscribers
- Subscribers don't know about publishers
- Messages typically broadcast to all subscribers
Use cases:
- Event notifications
- Real-time updates
- Logging and monitoring
- Cache invalidation
- Microservice events
Popular implementations:
- Google Cloud Pub/Sub
- Amazon SNS
- Azure Event Grid
- Apache Kafka
- Redis Pub/Sub
Business Context
Pub/sub enables event-driven architectures where services react to events without tight coupling, improving scalability and maintainability.
How Clever Ops Uses This
We implement pub/sub patterns for Australian businesses to enable event-driven AI systems, real-time notifications, and loosely coupled architectures.
Example Use Case
"AI model publishes "document processed" events to a topic; multiple services subscribe: notification service alerts user, analytics service logs metrics, storage service archives results."