跨微服务的事务

Question

我有两个实体：

实体A：

private Long idA;

实体 B：

private Long idB;
private Long fkA;

我的微服务只能保存、修改或删除B实体：

存储库：

@Repository
public interface BRepository extends CrudRepository<B, Long>{

}

伪造外部服务：

@FeignClient(value = "aExtClient", url = "${A_EXT_MS_URL}")
public interface AExtRemoteService {

    @DeleteMapping(path = "/a/{idA}", produces = MediaType.APPLICATION_JSON_VALUE)
    public Esito deleteA(@PathVariable(name = "idA") Long idA);

}

服务实现：

@Component
@Transactional(rollbackFor = BusinessServiceException.class)
public class BServiceImpl implements BService { 
    
    @Autowired
    private BRepository bRepository;
    
    @Autowired
    private AExtRemoteService aExtRemoteService;
    
    @Override
    public void deleteB(B b) {        
        
        Long idA = b.getFkA();
        
        bRepository.delete(b); //marker
        
        if(idA  != null) {
            aExtRemoteService.deleteA(idA);
        }
    }
    
}

外部服务只能保存、修改或删除 A 实体：

控制器：

@RestController
@RequestMapping("/a")
@CrossOrigin(origins = "${mocks.allowedCrossOrigins:*}")
public class AServiceMockController {

    @Autowired
    private AMockService aMockService;
    
    @DeleteMapping(value = {
            "/{idA}" }, produces = MediaType.APPLICATION_JSON_VALUE)
    public @ResponseBody ResponseEntity<Result> deleteA(@PathVariable(name = "idA") Long idA) {
        Result result = new Result();
        aMockService.deleteA(idA);
        result.setResult(true);
        result.setCod(String.valueOf(HttpStatus.OK.value()));
        result.setMess(HttpStatus.OK.name());
        return new ResponseEntity<>(result, HttpStatus.OK);
    }

}

服务：

@Service
public class AMockService {

    private final ARepository aRepository;    

    @Autowired
    public AMockService(ARepository aRepository) {
        this.aRepository = aRepository;
    }
    
    public void deleteA(Long idA) {
        A byId = aRepository.findById(idA).orElseThrow(NoSuchElementException);
        aRepository.delete(byId);
    }

}

存储库：

@Repository
public interface ARepository extends CrudRepository<A, Long>{

}

调用 deleteB 时，外部服务返回了这条消息：

Caused by: java.sql.SQLIntegrityConstraintViolationException: ORA-02292:  integrity constraint violated (X.YY) - child record found

我该如何解决？似乎没有考虑 bRepository.delete(b);

P.S。我可以访问外部服务，所以如果需要我可以修改它。

Answer 1

错误信息表明删除还没有完成。我要尝试的第一件事是在删除后手动 bRepository.flush()。

您可以在此处阅读有关冲洗的信息：https://www.baeldung.com/spring-data-jpa-save-saveandflush

Answer 2

您不能在微服务之间进行这样的交易 - 一个是因为您正在使用对服务 A 的远程 http 调用，并且它本质上无法参与您在服务 B 中启动的交易。您正在使用的交易是resource-local transaction. Second you are sharing a database in both the services and the remote http service is trying to delete a record which has a foreign key relation as a parent. Since you are using Spring transaction manager you can use a TransactionEventListener ( see here 到示例用法）以在 B 中的事务成功完成后调用删除 A。还有其他模式可以解决跨微服务的事务，例如 Saga

跨微服务的事务

Transactions Across Microservices

java

hibernate

transactions

distributed-transactions