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

![image](https://user-images.githubusercontent.com/15937567/130044663-cc8636c9-76ce-4cbe-8a82-52db8b66e049.png)


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!
```

public interface MeshEnvListener {
    /**
     * @return whether current environment support listen
     */
    default boolean isEnable() {
        return false;
    }
    void onSubscribe(String appName, MeshAppRuleListener listener);
    void onUnSubscribe(String appName);
}