在测试Mysql多主一从服务器，即一个从服务器多端口同步不同主库。本文记录了开启不同端口的操作。
详细步骤：
1、首先要先把my.cnf配置文件复制一份，开几个端口要复制几份当然要重新命名.
如：
cp /usr/local/mysql/my.cnf /usr/local/mysql/my3307.cnf
cp /usr/local/mysql/my.cnf /usr/local/mysql/my3308.cnf
cp /usr/local/mysql/my.cnf /usr/local/mysql/my3309.cnf
2、修改my3306.cnf my3307.cnf my3308.cnf文件把默认的3306端口改成 3307 3308 3309.
如：
[client]
port = 3308
socket = /tmp/mysql3308.sock
default-character-set=UTF
[mysqld]
port = 3308
socket = /tmp/mysql3308.sock
basedir = /usr/local/mysql
datadir = /www/mysqldata8
3、初始化数据库
/usr/local/mysql/scripts/mysql_install_db --datadir=/usr/local/mysql/mysqldata3306/ --user=mysql --basedir=/usr/local/mysql
/usr/local/mysql/scripts/mysql_install_db --datadir=/usr/local/mysql/mysqldata3307/ --user=mysql --basedir=/usr/local/mysql
/usr/local/mysql/scripts/mysql_install_db --datadir=/usr/local/mysql/mysqldata3308/ --user=mysql --basedir=/usr/local/mysql
4、启动mysql，要指定.cnf文件和目录启动
/usr/local/mysql/bin/mysqld_safe --defaults-extra-file=/usr/local/mysql/my3307.cnf --datadir=/usr/local/mysql/data/mysqldata3307 --user=mysql &
/usr/local/mysql/bin/mysqld_safe --defaults-extra-file=/usr/local/mysql/my3308.cnf --datadir=/usr/local/mysql/data/mysqldata3308 --user=mysql &
/usr/local/mysql/bin/mysqld_safe --defaults-extra-file=/usr/local/mysql/my3309.cnf --datadir=/usr/local/mysql/data/mysqldata3309 --user=mysql &
5、停止MYSQL，对应的sock文件。
/usr/local/mysql/bin/mysqladmin -uroot -S /tmp/mysql3308.sock shutdown
6、登陆mysql
mysql -S /tmp/mysq3308.sock -P 3308
ps:
关于mysql.sock文件是使用相同的文件还是使用原文件进行链接，我也不确定。我的方法是将mysql.sock文件进行链接了。
ln -sf /tmp/mysql.sock /tmp/mysql3307.sock