# mysql -h xxx.xxx.xxx.xxx -P4000
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Your MySQL connection id is 687
Server version: 5.7.25-TiDB-v6.5.0 TiDB Server (Apache License 2.0) Community Edition, MySQL 5.7 compatible
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MySQL [(none)]> set @@kv_read_timeout=1000;
ERROR 1193 (HY000): Unknown system variable 'kv_read_timeout'
The error message is misleading and not user-friendly enough to show why the program gets panic.
The root cause of the panic:
Another example: https://asktug.com/t/topic/1000741