undo_log不写日志，抛异常不会回滚？

Spring Cloud Eureka + Feign + Mybatis

Spring Boot version 2.1.2.RELEASE
Spring Cloud version Greenwich.RELEASE
Seata version 1.1.0

com.alibaba.cloud
spring-cloud-alibaba-seata
2.1.0.RELEASE


seata-all
io.seata




io.seata
seata-all
1.1.0

business-server服务
```
@Override
@GlobalTransactional
public void purchase(String userId, String commodityCode, Integer count) {
// 减库存
storageServiceClient.deduct(commodityCode, count);

// 创建订单
orderServiceClient.create(userId, commodityCode, count);
}
```

order-server服务
```
@Override
public boolean create(String userId, String commodityCode, Integer count) {
// 计算订单金额
final BigDecimal orderMoney = calculate(commodityCode, count);
// 支付
accountServiceClient.debit(userId, orderMoney);

// 保存订单
OrderDTO orderDTO = new OrderDTO();
orderDTO.setUserId(userId);
orderDTO.setOrderNo(UUID.randomUUID().toString().replace("-", ""));
orderDTO.setCommodityCode(commodityCode);
orderDTO.setCount(count);
orderDTO.setMoney(orderMoney);
return orderMapper.insert(orderDTO);
}
```

account-server服务
```
@Override
public void debit(String userId, BigDecimal orderMoney) {
// 查余额
BigDecimal money = accountMapper.queryMoney(userId);
if (money.compareTo(orderMoney) < 0) {
try {
throw new Exception("余额不足");
} catch (Exception e) {
e.printStackTrace();
}
} else {
// 扣钱
accountMapper.debit(userId, orderMoney);
}
}
```

1. 抛异常不会回滚
余额不足抛异常，还是扣了库存，保存了订单

2. undo_log不写日志，没数据
-----------------------------------
2020-03-27 10:52:28.873 WARN 8516 --- [nio-9094-exec-4] c.a.c.seata.web.SeataHandlerInterceptor : xid in change during RPC from 192.168.160.128:8091:2039003107 to null

3. 有时会出现如下异常
-----------------------------------
io.seata.core.exception.RmTransactionException: Response[ TransactionException[Could not register branch into global session xid = 192.168.160.128:8091:2039003036 status = AsyncCommittin ]

Start by tracing the @GlobalTransactional purchase entry point through the Feign calls and the account-server debit method, where the exception is caught. Inspect the undo_log records and the SeataHandlerInterceptor warning while reproducing the insufficient-balance case; done means the rollback behavior and missing transaction records are explained and verified.

Written by the indexing model from the issue text.