The Transactional Outbox Pattern
Learn how the transactional outbox pattern reliably bridges a database transaction and Kafka publishing, avoiding dual-write inconsistencies in Spring Boot.
The Dual-Write Problem
A common bug: a service updates its database and publishes a Kafka event in two separate operations. If one succeeds and the other fails, the system becomes inconsistent.
The transactional outbox pattern eliminates this risk.
Core Idea
Instead of publishing directly, write the event into an outbox table within the same database transaction as your business change.
A separate process then reads the outbox and publishes to Kafka.
All lessons in this course
- Understanding Kafka Transactions
- Implementing Transactional Producers
- Exactly-Once Processing Semantics
- The Transactional Outbox Pattern