SpringCloud + Feign 事务不回滚 解决方案

看issue发现很多人也有这个问题，我最近也碰到了，然后跟踪了一下源码，总算解决了。

下面给出我的解决步骤：

1. 打开LCN Logger
`logging.level.com.codingapi.txlcn = debug`

2. 检查日志中是否包含以下log。如包含，转6
`com.codingapi.txlcn.tracing.Tracings : tracing apply group:693a5ae3226537.....`

3. 检查日志中的各服务log中groupId是否一致 。如一致，转6
`c.c.t.t.c.context.DefaultGlobalContext : Start TxContext[693a5ae3226537]`

4. 检查是否用了 @EnableWebMvc 注解。如用了，转6
5. 添加MVC拦截器
```
public class WebMvcConfiguration extends WebMvcConfigurationSupport {
.........其它配置省略...........
public void addInterceptors(InterceptorRegistry registry) {
registry.addInterceptor(new SpringTracingApplier());
}
}
6. 结束
```

Start by reproducing the Spring Cloud and Feign transaction rollback problem described in the issue, then enable LCN debug logging and compare tracing group IDs across service logs. Check whether @EnableWebMvc is present and whether the SpringTracingApplier interceptor is registered; done means identifying and documenting the condition that prevents rollback or confirming the provided workaround.

Written by the indexing model from the issue text.