- [ ] I have searched the [issues](https://github.com/apache/incubator-dubbo/issues) of this repository and believe that this is not a duplicate.
- [ ] I have checked the [FAQ](https://github.com/apache/incubator-dubbo/blob/master/FAQ.md) of this repository and believe that this is not a duplicate.

### Environment

* Dubbo version: xxx
* Operating System version: xxx
* Java version: xxx

### Steps to reproduce this issue

1. xxx
2. xxx
3. xxx

Pls. provide [GitHub address] to reproduce this issue.

### Expected Result

What do you expected from the above steps？

### Actual Result

What actually happens?

If there is an exception, please attach the exception trace:

```
Just put your stack trace here!
```

} catch (Throwable e) {
            logger.warn(e.getMessage(), e);
        }
        try {
            super.close();
        } catch (Throwable e) {
            logger.warn(e.getMessage(), e);
        }
        try {
            disconnect();
        } catch (Throwable e) {
            logger.warn(e.getMessage(), e);
        }
        try {
            doClose();
        } catch (Throwable e) {
            logger.warn(e.getMessage(), e);
        }
    }
    @Override
    public void close(int timeout) {
        ExecutorUtil.gracefulShutdown(executor, timeout);
        close();
    }
    @Override
    public String toString() {
        return getClass().getName() + " [" + getLocalAddress() + " -> " + getRemoteAddress() + "]";
    }
    /**
     * Open client.