Unable to connect to ShardingSphere-Proxy

[flyer5200]

Bug Report

I use shardingsphere-proxy version 5.5.1, and the client cannot connect to the proxy, and the following error appears：

Unknown exception. More details: java.lang.NullPointerException: Cannot invoke “org.apache.shardingsphere.infra.metadata.database.ShardingSphereDatabase.getRuleMetaData()” because the return value of “org.apache.shardingsphere.infra.metadata.ShardingSphereMetaData.getDatabase(String)” is null

Version: ShardingSphere-Proxy 5.5.1 cluster mode (zookeeper)

[terrymanu]

How to reproduce it?

[flyer5200]

Please refer to the steps to reproduce the #34178

This problem only exists in Alibaba Cloud DMS when performing datasource validation.
There is no such problem when using MySQL client or Navicat.

Under the premise of ensuring network connectivity, DMS will perform an instance availability check when entering the data source, usually sending select 1 to shardingsphere-proxy. At this time, the shardingsphere-proxy will throw the above exception:
Unknown exception. More details: java.lang.NullPointerException: Cannot invoke “org.apache.shardingsphere.infra.metadata.database.ShardingSphereDatabase.getRuleMetaData()” because the return value of “org.apache.shardingsphere.infra.metadata.ShardingSphereMetaData.getDatabase(String)” is null