Spring嵌套事务​​最佳实践

如何解决Spring嵌套事务​​最佳实践

我的情况是，我需要 orderService.createOrder() 方法和内部 walletService.reduceBalance() 方法。我希望 orderService.createOrder() 方法具有 READ_COMMITED 隔离级别，而 walletService.reduceBalance() 具有 REPEATABLE_READ 隔离级别。

但是，据我了解，因为 walletService.reduceBalance() 在 orderService.createOrder() 内部，尽管有注释，它仍将具有 READ_COMMITED 隔离（因为这一切都发生在单个物理事务中）。

public class OrderService {

  private WalletService walletService;
  
  @Transactional
  public void createOrder(Long userId) {
    //some order creation,reads a lot of data
    walletService.reduceBalance(userId,orderPrice);
    //other operations
  }
}

public class WalletService {

  private WalletRepository walletRepository;
  
  @Transactional(isolation = Isolation.REPEATABLE_READ)
  public void reduceBalance(Long userId,BigDecimal amount) {
   Wallet wallet = walletRepository.getById(userId);
   wallet.setBalance(wallet.getBalance().substract(amount);
  }

}

第一个解决方案是使 orderService.createOrder() REPEATABLE_READ。但在这种情况下，它会减慢应用程序的速度，因为该方法读取了大量数据，而 REPEATABLE_READ 会对这些数据加锁。

public class OrderService {

  private WalletService walletService;
  
  @Transactional(isolation = Isolation.REPEATABLE_READ)
  public void createOrder(Long userId) {
    //some order creation,BigDecimal amount) {
   Wallet wallet = walletRepository.getById(userId);
   wallet.setBalance(wallet.getBalance().substract(amount);
  }

}

第二种解决方案是使 walletService.reduceBalance() propogation=REQUIRES_NEW 将创建具有正确隔离级别的单独物理事务。但在这种情况下，如果 walletService.reduceBalance() 已提交事务且稍后在 orderService.createOrder() 中发生异常，则订单创建将回滚并仍会提交 reduce balance。

public class OrderService {

  private WalletService walletService;
  
  @Transactional
  public void createOrder(Long userId) {
    //some order creation,orderPrice);
    //other operations
  }
}

public class WalletService {

  private WalletRepository walletRepository;
  
  @Transactional(isolation = Isolation.REPEATABLE_READ,propagation = Propagation.REQUIRES_NEW)
  public void reduceBalance(Long userId,BigDecimal amount) {
   Wallet wallet = walletRepository.getById(userId);
   wallet.setBalance(wallet.getBalance().substract(amount);
  }

}

你能提出更好的处理这种情况的方法吗？