##想当然的指定hostname和端口。。。。失败
[root@mysql01 ~]# /opt/mysql/bin/mysql -uroot -h localhost -P 3307 -p
Enter password:
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/tmp/mysql.sock' (2)

##正确方法，指定通信协议 --protocol tcp
[root@mysql01 ~]# /opt/mysql/bin/mysql -uroot -h localhost -P 3307 -p --protocol tcp
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 8
Server version: 5.6.31-log Source distribution

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