Linux下修改mysql的默认端口号

1. 登录mysql

[root@test /]# mysql -u root -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 92
Server version: 5.1.66 Source distribution
 
Copyright (c) 2000, 2012, 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>

2. 使用命令show global variables like 'port';查看端口号

mysql> show global variables like 'port';
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| port | 3306 |
+---------------+-------+
1 row in set (0.00 sec)

3. 修改端口，编辑/etc/my.cnf文件，早期版本有可能是my.conf文件名，增加端口参数，并且设定端口，注意该端口未被使用，保存退出。

root@test etc]# vi my.cnf
[mysqld]
port=3506
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
user=mysql

建议禁用符号链接以防止各种安全风险

symbolic-links=0
 
[mysqld_safe]
log-error=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid
 
"my.cnf" 11L, 261C written
[root@test etc]#

4. 重新启动mysql

[root@test ~]# /etc/init.d/mysqld restart
Stopping mysqld: [ OK ]
Starting mysqld: [ OK ]

5.再次登录后检查端口已修改为’3506’.

root@test etc]# mysql -u root -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.1.66 Source distribution
 
Copyright (c) 2000, 2012, 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> show global variables like 'port';
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| port | 3506 |
+---------------+-------+
1 row in set (0.00 sec)
 
mysql>

6.一些注意项

1. 需要保证自己系统的对应段口号已经打开，即处于可以使用的状态。
   使用netstat -tln查看自己系统的可使用端口：
   也可以使用netstat -a查看所有服务端口
   2.如果想要使用的端口没有被打开，则

（1）执行
	firewall-cmd --zone=public --add-port=6379/tcp --permanent
（2）重新载入
	firewall-cmd --reload

就可以打开指定的端口，再使用上面的过程去更改即可。