I am currently developing a microservices architecture consisting of two services, and I’m facing a challenge related to transaction management and error handling.

• Microservice A: This service is responsible for receiving data, saving it to a PostgreSQL database using Entity Framework Core, and publishing relevant events to Microservice B via Kafka using MassTransit.

    await _context.DeliveryDocuments.AddRangeAsync(deliveryDocuments, cancellationToken);
  
    await _context.SaveChangesAsync(cancellationToken);
  
    await _publisher.Publish(new DeliveryRequestSavedEvent(deliveryRequest, EventType.Create), cancellationToken);
  

• Microservice B: This service consumes the messages published by Microservice A and performs certain business logic based on the received data. However, there are scenarios where Microservice B can fail during processing, potentially throwing exceptions.

     public async Task Consume(ConsumeContext<DeliveryRequestFromSiteBusMessage> context)    
     throw new Exception();
  

Given this architecture, I want to ensure that if Microservice B encounters an error, any associated changes made by Microservice A (i.e., saving data to the database) are not committed. Essentially, I am looking to implement a rollback mechanism to maintain data consistency across the services.

In my service A the logic is very simple. It’s very unlikely that data will fail during saving to db, otherwise on service B its alloat of risk that something goes wrong, alloat of complex logic so i need to provide some mechanism that will commit transaction on microservice 1 after the data is consumed and handled on service B, the delay doesn`t matter, about cleanup i think its not possiable because im not just creating new objects, im also existing once, and i dont want to hold state of previous objects, so i dont think cleanup is a good idea.

I would like to know the best approaches, tools, and design patterns to effectively manage transactions across these microservices. Specifically:

1. What are the recommended patterns for ensuring data consistency, such as the Outbox Pattern or Sagas? Which one of them is suitable in my case?
2. How can I implement compensating transactions to roll back changes in Microservice A if Microservice B fails?
3. I read about transaction outbox pattern on masstransit
   https://masstransit.io/documentation/patterns/transactional-outbox
   but i understand it’s not working with kafka, so i guess i left with saga?

Any insights or examples of how to achieve this type of rollback mechanism in a microservices environment would be greatly appreciated!

Thank you!