Idempotency and Message Deduplication
Make microservice operations safe to retry by designing idempotent handlers and deduplicating messages in distributed systems.
Retries Cause Duplicates
Distributed systems deliver messages at least once. A timeout or retry can make the same request arrive twice — and charge a card or create an order twice.
What Idempotency Means
An operation is idempotent if doing it many times has the same effect as doing it once. Repeating it changes nothing beyond the first application.
All lessons in this course
- Synchronous vs. Asynchronous Communication
- Challenges in Distributed Systems
- API Gateway and Service Discovery
- Idempotency and Message Deduplication