Axon 4 - JVM 重启后再次出现 Saga 运行

Question

我正在使用带 Spring 引导的 Axon4。创建简单的传奇。它在运行中的 JVM 期间运行良好。但是，一旦重新启动，它会再次重新运行 Saga。

试图将 JpaSagaStore 用于持久化，但没有成功。以下是代码片段。请帮忙

@Configuration
public class AxonConfig {
    @PersistenceContext
    private EntityManager entityManager;

    @Bean
    public SagaStore sagaStore() {
        return JpaSagaStore.builder().entityManagerProvider(new SimpleEntityManagerProvider(entityManager)).build();
    }
}    

@Saga(sagaStore = "sagaStore")
@Slf4j
public class OrderSaga {

    @Autowired
    private transient CommandGateway commandGateway;

    private UUID orderId;

    private boolean passed;

    @StartSaga
    @SagaEventHandler(associationProperty = "orderId")
    public void on(OrderPlacedEvt evt) {
        log.debug("handling {}", evt);
        if (!passed) {
            orderId = evt.getOrderId();
            UUID shipmentId = UUID.randomUUID();
            associateWith("shipmentId", shipmentId.toString());
            commandGateway.send(new PrepareShipmentCmd(shipmentId, evt.getDestination()));
        }
    }


    @SagaEventHandler(associationProperty = "shipmentId")
    public void on(ShipmentPreparedEvt evt) {
        log.debug("handling {}", evt);
        log.debug("orderId: {}", orderId);
        commandGateway.send(new RegisterShipmentForOrderPreparedCmd(orderId, evt.getShipmentId()));
    }

    @SagaEventHandler(associationProperty = "shipmentId")
    @EndSaga
    public void on(ShipmentArrivedEvt evt) {
        log.debug("handling {}", evt);
        log.debug("orderId: {}", orderId);
        commandGateway.send(new RegisterShipmentForOrderArrivedCmd(orderId, evt.getShipmentId()));
    }
}

Answer 1

对 Prashant 问题的解决方案得到进一步讨论 here

简而言之，数据库在每次启动时都设置为 create。因此，跟踪 Saga 处理事件的距离的令牌（用于跟踪事件处理器）在每次启动应用程序时都会重置。

因此将线路 spring.jpa.properties.hibernate.hbm2ddl.auto=create 切换为 spring.jpa.properties.hibernate.hbm2ddl.auto=update 解决了问题。

Axon 4 - JVM 重启后再次出现 Saga 运行

Axon 4 - Saga run again after JVM restart

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