About Microservices.io

Microservices.io is brought to you by Chris Richardson. Experienced software architect, author of POJOs in Action and the creator of the original CloudFoundry.com. His latest startup is eventuate.io, a microservices application platform.


Microservices consulting and training

Chris offers a comprehensive consulting services, workshops and hands on training classes to help you use microservices effectively.

Avoid the pitfalls of adopting microservices and learn essential topics, such as service decomposition and design and Kubernetes. Find out more


Microservices in Sydney and Melbourne

I'll be speaking at the YOW! conference and teaching a one day microservices workshop in Sydney and Melbourne. 10% discount with JOINMEATYOW18.

Learn more


Learn more about microservices

Chris offers a comprehensive set of resources for learning about microservices including articles, an O'Reilly training video, and example code.

Learn more


Example microservices applications

Want to see an example? Check out Chris Richardson's example applications. See code


Get the book: Microservice patterns


Signup for the newsletter

A new microservices application platform that solves distributed data management problems.

Join the microservices google group

Pattern: Publish events using database triggers

Context

A service typically need to atomically update the database and publish messages/events. For example, perhaps it uses the Saga pattern. In order to be reliable, each step of a saga must atomically update the database and publish messages/events. Alternatively, it might use the Domain event pattern, perhaps to implement CQRS. In either case, it is not viable to use a distributed transaction that spans the database and the message broker to atomically update the database and publish messages/events.

Problem

How to reliably/atomically update the database and publish messages/events.

Forces

  • 2PC is not an option

Solution

One or more database triggers insert events into an EVENTS table, which is polled by a separate process that publishes the events.


Copyright © 2018 Chris Richardson • All rights reserved • Supported by Kong.