Transactional Outbox Pattern

This is a lecture from the Cockroach University course “Event-Driven Architecture with Java”.

In this lecture, students are introduced some of the principles of building microservices such as synchronous, and asynchronous messages, data isolation, and event-driven architecture.

We discuss the dual-write problem that occurs when you try to build an event-driven system. We also discuss the transactional outbox pattern and how it can be used to avoid the dual-write problem.

Finally, we introduce CockroachDB’s Change Data Capture which can be used in conjunction with the transactional outbox pattern to simplify the implementation of an event-driven system.

[HaberzettelJNM]

Really nice explanations and animations. Good job.

[moofymoo]

yay! someone explained what problem outbox solves!

[jasper]

Animation is top notch. I liked your explanation. Thanks a lot

[dezee]

Good presentation. I would consider using a database post commit trigger to send a notification to an external system, ie queue, cache etc. What issues might this not solve?

[attilanagy]

Thank you very much, it's a really good explanation for the outbox pattern.

[D]

Good explanation and animation. How do you ensure messages are delivered in the right order? With time Outbox table will only grow in size. Is there a purge feature? Is there 1 Outbox table for all transactions in all entities in one DB?

[ankuriiita]

RDBMS in general is not optimised for deletes. How do you handle that? Will it cause table bloat?