README.md

intro:

The Saga pattern is an architectural pattern which provides an alternative approach to big and long running ACID transactions.
It takes a business process and breaks it up into small isolated steps – each of them with its own transaction./ The overall consistency is provided by manually reverting past actions.

there are 2 types of saga:

• event-based(distributed). Every microservice decides to push the message further

• orchestrator based(centralized). There is only one service being an orchestrator decides to push a message further

• refs: whitepaper

notes:

There are three services involved to saga(creator-service,logger-service,validator-service).

General funcitonality is provided by the packages:

• logic
• messages

The saga message involves all appropriate information for orchestration:

    Saga saga = new Saga()
                .addChapter(new Chapter("create", "creator-service", Status.READY, "test-data"))
                .addChapter(new Chapter("validate", "validator-service", Status.READY, "test-data"))
                .addChapter(new Chapter("log", "logger-service", Status.READY, "test-data"))
                .addChapter(new Chapter("diff_creator", "creator-service", Status.READY, "test-data"))
                .addChapter(new Chapter("validate", "validator-service", Status.READY, "test-data"))
                .addChapter(new Chapter("log", "logger-service", Status.READY, "test-data"))
        ;

Service example:

@Slf4j
@EnableSaga
@SagaChapter(title = "create")
public class Creator {

    @ChapterAction
    public String createEntity(String name){
      log.info(" entity with name created {} ",name);
      return "entity["+name+"]";
    }

    @ChapterRollback
    public String removeEntity(String name){
      log.info(" entity with name removed {} ",name);
      return "entity["+name+"]";
    }
    
}