Tram Tutorial

Light-tram-4j is the foundation of event driven frameworks and handles transactional messaging without XA. On top of light-tram-4j, there is light-saga-4j to handle distributed transactions across multiple microservices. There is also a framework light-eventuate-4j to support Event Sourcing and CQRS architecture. All tutorials here are showing basic message, event or command delivery from one service to another service.

Todo-list

This is a Hello World type of application that shows the features of light-tram-4j. Unlike the todo-list implemented in light-eventuate-4j with Event Sourcing and CQRS, this demo application will only use message/event from a service that is responsible for inserting, updating and deleting todo items to another service that is responsible for query todo items.

Development

Different from light-evenutate-4j, Light-tram-4j handles message delivery in a lighter way and doesn’t have event sourcing and CQRS. Light-tram-4j doesn’t handle event replay and doesn’t worry about aggregate status.

Light-tram-4j can be simply used in those services which handle its local database process and send message to message broker together.

Development API with light-tram-4j

Message/Event store: The normal solution for the message/event store is to use message broker for the message queue.The traditional solution is to use a distributed transaction that spans the database and the message broker. However, distributed transactions are not a good choice for modern application. Use a database table as a message queue A straightforward way to reliably publish messages is to use a database table as a temporary message queue. Read More »

Todo list tutorial

It’s challenging for micro-service API to update data (e.g. a Domain-Driven design aggregate) and publish a message, such as a domain event. The traditional approach of using 2PC/JTA isn’t a good fit for micro-service applications. The light-tram-4j framework implements an alternative mechanism based on the Application Events pattern. When an application creates or updates data, as part of that ACID transaction, it inserts an event into a MESSAGE table. A separate process publishes those events to a message broker, such as Apache Kafka. Read More »