wow, you are right. My MySQL database runs at 192.168.3.82:3306, my xwiki runs at 192.168.3.81:8080/xwiki, and my tomcat 192.168.3.81:8080 is normal.
My xwiki is connected to 192.168.3.82, I need to execute flush hosts in the 192.168.3.81mysql database according to the error message