2、socket mysql.sock的作用是server和client在同一臺服務(wù)器，并且使用localhost進(jìn)行鏈接的時(shí)候，就會(huì )使用socket來(lái)進(jìn)行連接——僅此而已
也就是：為主機名為localhost建立的MySQL連接，該連接過(guò)程通過(guò)一個(gè)套接字文件mysql.socket實(shí)現的。所以該文件被刪后，用localhost用戶(hù)是連接不到MySQL服務(wù)器的。
必須建立一條tcp/ip連接，即使用127.0.0.1而不是localhost作為-h的參數去連接MySQL服務(wù)器，如：mysqladmin -h 127.0.0.1 -u root -p shutdown，強制地建立一條tcp/ip連接；
關(guān)閉MySQL服務(wù)器，再重新以localhost為主機名啟動(dòng)MySQL服務(wù)器，它就會(huì )重新創(chuàng )建一個(gè)套接字文件。
對上文加以測試深入了解；
查看mysql.sock具體路徑：
[root@Wonhigh-Test16 ~]# ps -ef | grep mysql.sock|grep -v "grep"
mysql 31108 30650 0 Sep10 ? 00:03:17 /usr/sbin/mysqld --basedir=/usr --datadir=/var/lib/mysql --plugin-dir=/usr/lib64/mysql/plugin --user=mysql --log-error=/var/lib/mysql/Wonhigh-Test16.err --pid-file=/var/lib/mysql/Wonhigh-Test16.pid --socket=/var/lib/mysql/mysql.sock --port=3306
[root@Wonhigh-Test16 ~]#
轉移套接字文件 mysql.sock
[root@Wonhigh-Test16 ~]# mv /var/lib/mysql/mysql.sock /var/lib/mysql/mysql1.sock
確認本地登錄情況
[root@Wonhigh-Test16 ~]# mysql -uroot -p123456
Warning: Using a password on the command line interface can be insecure.
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2)
[root@Wonhigh-Test16 ~]#
嘗試127.0.0.1 tcp/ip連接（第三方工具遠程連接都可以‘連接屬性會(huì )顯示為T(mén)CP/IP ’）
[root@Wonhigh-Test16 ~]# mysql -uroot -p123456 -h127.0.0.1
Warning: Using a password on the command line interface can be insecure.Welcome to the MySQL monitor. Commands end with ; or \g.Your MySQL connection id is 127Server version: 5.6.19-logCopyright (c) 2000, 2014, Oracle and/or its affiliates. All rights reserved.Oracle is a registered trademark of Oracle Corporation and/or itsaffiliates. Other names may be trademarks of their respective owners.Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. mysql>
恢復本地連接
[root@Wonhigh-Test16 ~]# mv /var/lib/mysql/mysql1.sock /var/lib/mysql/mysql.sock
[root@Wonhigh-Test16 ~]# mysql -uroot -p123456
Warning: Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 121
Server version: 5.6.19-log MySQL Community Server (GPL)
Copyright (c) 2000, 2014, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> exit
Bye
[root@Wonhigh-Test16 ~]#
