spring-boot-saga-pattern

Spring Boot Saga Pattern

Overview

Implements distributed transactions across microservices using the Saga Pattern. Replaces two-phase commit with a sequence of local transactions and compensating actions. Supports choreography (event-driven) and orchestration (centralized coordinator) approaches with Kafka, RabbitMQ, or Axon Framework.

When to Use

• Building distributed transactions across multiple microservices
• Replacing two-phase commit (2PC) with a more scalable solution
• Handling transaction rollback when a service fails
• Ensuring eventual consistency in microservices architecture
• Implementing compensating transactions for failed operations
• Coordinating complex business processes spanning multiple services

Trigger phrases: distributed transactions, saga pattern, compensating transactions, microservices transaction, eventual consistency, rollback across services, orchestration pattern, choreography pattern

Instructions

1. Design Transaction Flow

Map the sequence of operations and their compensating transactions:

Order → Payment → Inventory → Shipment
  ↓        ↓        ↓          ↓
Cancel  Refund   Release    Cancel

Validation: Verify every forward step has a corresponding compensation.

2. Choose Implementation Approach

Approach	Use Case	Stack
Choreography	Greenfield, few participants	Spring Cloud Stream + Kafka/RabbitMQ
Orchestration	Complex workflows, brownfield	Axon Framework, Eventuate Tram, Camunda

Validation: Review team expertise and system complexity before choosing.

3. Implement Services with Local Transactions

Each service completes its local ACID transaction atomically:

@Service
@RequiredArgsConstructor
public class OrderService {
    private final OrderRepository orderRepository;
    private final KafkaTemplate<String, Object> kafka;

    @Transactional
    public Order createOrder(CreateOrderCommand cmd) {
        Order order = orderRepository.save(new Order(cmd.orderId(), cmd.items()));
        kafka.send("order.created", new OrderCreatedEvent(order.getId(), order.getItems()));
        return order;
    }
}