How to implement distributed transactions using Spring Cloud Saga

Spring Cloud Saga provides a declarative way to coordinate distributed transactions, simplifying the implementation process: Add Maven dependency: spring-cloud-starter-saga. Create a Saga Orchestrator (@SagaOrchestration). Write participants to implement SagaExecution to execute business logic and compensation logic (@SagaStep). Define state transitions and actors in the Saga. By using Spring Cloud Saga, atomicity between different microservice operations is ensured.

How to implement distributed transactions in Spring Cloud Saga

Distributed transactions are essential to ensure the integrity of data between different microservices Sex is crucial. Spring Cloud Saga provides a declarative way to coordinate distributed transactions, simplifying the implementation process.

Dependencies

Add the following dependencies in the Maven project:

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-saga</artifactId>
    <version>3.1.5</version>
</dependency>

Create Saga

Saga is the coordinator of distributed transactions. To create a Saga, you need to create a class with the @SagaOrchestration annotation:

@SagaOrchestration
public class OrderSaga {

    private final SomeService someService;
    private final OtherService otherService;

    public OrderSaga(SomeService someService, OtherService otherService) {
        this.someService = someService;
        this.otherService = otherService;
    }

    // 定义 Saga 的状态转换
    // ...
}

Writing Participant

The participant is the actual execution in the Saga Business logic components. They need to implement the SagaExecution interface:

public class SomeServiceImpl implements SagaExecution<OrderSaga> {

    // 定义业务逻辑
    // ...
}

Practical case

Suppose we have an order system, which involves the following operations:

• Create order
• Deduct item quantity from inventory
• Send order confirmation email

We can use Spring Cloud Saga to coordinate these operations:

Order Saga

@SagaOrchestration
public class OrderSaga {

    // 定义 Saga 的各个阶段
    @SagaStep(output = "createOrder")
    public void createOrder(SagaExecution<OrderSaga> sagaExecution) {
        // 创建订单
    }

    @SagaStep(input = "createOrder", output = "decrementStock")
    public void decrementStock(SagaExecution<OrderSaga> sagaExecution) {
        // 从库存中扣除商品数量
    }

    @SagaStep(input = "decrementStock", output = "sendEmail")
    public void sendEmail(SagaExecution<OrderSaga> sagaExecution) {
        // 发送订单确认电子邮件
    }
}

Participant

public class OrderServiceImpl implements SagaExecution<OrderSaga> {

    // 实现创建订单的逻辑
    @Override
    public void execute(OrderSaga saga, OrchestrationContext<OrderSaga> context) {
        // ...
    }

    // 实现补偿逻辑
    @Override
    public void compensate(OrderSaga saga, OrchestrationContext<OrderSaga> context) {
        // ...
    }
}

public class StockServiceImpl implements SagaExecution<OrderSaga> {

    // 实现扣减库存的逻辑
    @Override
    public void execute(OrderSaga saga, OrchestrationContext<OrderSaga> context) {
        // ...
    }

    // 实现补偿逻辑
    @Override
    public void compensate(OrderSaga saga, OrchestrationContext<OrderSaga> context) {
        // ...
    }
}

public class EmailServiceImpl implements SagaExecution<OrderSaga> {

    // 实现发送电子邮件的逻辑
    @Override
    public void execute(OrderSaga saga, OrchestrationContext<OrderSaga> context) {
        // ...
    }

    // 发送电子邮件不需要补偿逻辑
    @Override
    public void compensate(OrderSaga saga, OrchestrationContext<OrderSaga> context) {

    }
}

By using Spring Cloud Saga, we implement distributed transactions and ensure Atomicity between order creation, inventory deduction and email sending.

The above is the detailed content of How to implement distributed transactions using Spring Cloud Saga. For more information, please follow other related articles on the PHP Chinese website!