- [*] 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: 3.0.2.1
* Operating System version: Ubuntu20
* Java version: 1.8

### Steps to reproduce this issue

1.  telnet localhost 22222
2. dubbo>ls service


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

### Expected Result
list services

### Actual Result

```
ls service :fail to execute commandContext by org.apache.dubbo.registry.client.ServiceDiscoveryRegistry cannot be cast to org.apache.dubbo.registry.support.AbstractRegistry
```

logger.warn("Cannot find app mapping for service " + url.getServiceInterface() + ", will not migrate.", e);
        }
        if (CollectionUtils.isEmpty(subscribedServices)) {
            if (check) {
                throw new IllegalStateException("Should has at least one way to know which services this interface belongs to, subscription url: " + url);
            }
            return;
        }
        subscribeURLs(url, listener, subscribedServices);
    }
    @Override
    public final void unsubscribe(URL url, NotifyListener listener) {
        if (!shouldSubscribe(url)) { 
            return;
        }
        url = addRegistryClusterKey(url);
        doUnsubscribe(url, listener);
    }
    private URL addRegistryClusterKey(URL url) {
        String registryCluster = serviceDiscovery.getUrl().getParameter(REGISTRY_CLUSTER_KEY);
        if (registryCluster != null && url.getParameter(REGISTRY_CLUSTER_KEY) == null) {
            url = url.addParameter(REGISTRY_CLUSTER_KEY, registryCluster);
        }
        return url;
    }
    public void doUnsubscribe(URL url, NotifyListener listener) {
        
        writableMetadataService.unsubscribeURL(url);
        String protocolServiceKey = url.getServiceKey() + GROUP_CHAR_SEPARATOR + url.getParameter(PROTOCOL_KEY, DUBBO);
        Set<String> serviceNames = writableMetadataService.getCachedMapping(url);