All, When I tried to connect in centos 7 mariadb 10.2.11 server using root user, by mistake I gave wrong user name, but it connected successfully. I am not sure why. When I check show databases, it didnt list all DBs, but when I connect with root again, I can see all valid Dbs. Is this normal that even if I give wrong user, it authenticate into DB server from root. [root@ipaddr ~]# mysql -u rot Welcome to the MariaDB monitor. Commands end with ; or \g. Your MariaDB connection id is 22 Server version: 10.2.11-MariaDB MariaDB Server Copyright (c) 2000, 2017, Oracle, MariaDB Corporation Ab and others. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. MariaDB [(none)]> show databases; +--------------------+ | Database | +--------------------+ | information_schema | | test | +--------------------+ 2 rows in set (0.00 sec) MariaDB [(none)]> exit Bye [root@ipaddr~]# mysql -u root Welcome to the MariaDB monitor. Commands end with ; or \g. Your MariaDB connection id is 24 Server version: 10.2.11-MariaDB MariaDB Server Copyright (c) 2000, 2017, Oracle, MariaDB Corporation Ab and others. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. MariaDB [(none)]> show databases; +--------------------+ | Database | +--------------------+ | mydb01 | | information_schema | | mydb02 | | mysql | | performance_schema | | test | +--------------------+ 6 rows in set (0.00 sec)