MYSQL 多实例运行

mysql可以以多实例的方式，实现一台服务器，运行在不同端口不同数据文件的mysql，它们是相互独立的。

1、关闭原有的默认端口3306的mysql:service mysqd stop

2、拷贝或创建数据文件

#拷贝现有的mysql数据库文件
#我的在/var/lib/mysql，拷贝一份至mysql_3307文件夹
[root@test-206 ~]# cp -r /var/lib/mysql /var/lib/mysql_3307

#创建一个新的空数据库
[root@test-206 ~]# mkdir /var/lib/mysql_3307
[root@test-206 ~]# mysql_install_db --datadir=/var/lib/mysql_3307 --user=mysql

3、给数据文件赋予mysql用户与用户组

[root@test-206 ~]# chown -R mysql.mysql /var/lib/mysql_3307

4、创建multi的配置cnf文件,用于启动这个mysql实例（如3307）载入执行

[root@test-206 ~]# touch /usr/local/my_multi.cnf

文件中写入你想要的配置，如下为典型配置

[mysqld_multi]
mysqld     = /usr/bin/mysqld_safe
mysqladmin = /usr/bin/mysqladmin
user       = root　　　　#用于登陆和关闭此服务
password   = 123456　　　#同上

[mysqld3307]
socket     = /tmp/mysql_3307.sock
port       = 3307
pid-file   = /var/lib/mysql_3307/3307.pid
datadir    = /var/lib/mysql_3307/
log        = /var/lib/mysql_3307/3307.log
character-set-server    = utf8
user       = mysql

 5、启动你的多实例

[root@test-206 ~]# mysqld_multi --defaults-extra-file=/usr/local/my_multi.cnf start 3307

6、检查是否启动成功

[root@test-206 ~]# netstat -ntlp
tcp        0      0 :::3306                     :::*                       LISTEN      3919/mysqld
tcp        0      0 :::3307                     :::*                        LISTEN      15027/mysqld

如果没有发现你要的端口号mysql实例，可以检查下/var/lib/mysql_3307/3307.log文件,排除问题

7、设置新的密码

[root@test-206 ~]#  mysqladmin -uroot -S /tmp/mysql_3307.sock password 123456

8、登入你的新实例

[root@test-206 ~]# mysql -uroot -S /tmp/mysql_3307.sock -p
Enter password:
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 1
Server version: 5.5.20-log Distributed by The IUS Community Project

Copyright (c) 2000, 2011, 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>

再次确认下，你的这个实例，是不是用的mysql_3307这个文件夹的数据

mysql> show variables like '%datadir%';
+---------------+----------------------+
| Variable_name | Value                |
+---------------+----------------------+
| datadir       | /var/lib/mysql_3307/ |
+---------------+----------------------+
1 row in set (0.00 sec)

mysql>

恩，没有错！最后，搞搞权限、用户之类。收工!

#查用户
mysql> select user,host from mysql.user;
+------+-----------+
| user | host      |
+------+-----------+
| root | 127.0.0.1 |
| root | ::1       |
|      | localhost |
| root | localhost |
|      | test-206  |
| root | test-206  |
+------+-----------+
6 rows in set (0.00 sec)

#设权限
mysql> grant all on *.* to root@'%' identified by 'root' with grant option;
Query OK, 0 rows affected (0.00 sec)

##查权限
mysql> show grants for root;

##创用户
mysql> grant select on *.* to backup@'%' identified by 'backup';
Query OK, 0 rows affected (0.00 sec)