一台服务器多实例mysql做主从复制

在一台服务器上开两个端口的mysql（3306、3307），做成主从复制环境

1）安装mysql（安装过程这里就不做过多介绍）
参考：http://www.cnblogs.com/kevingrace/p/6109679.html

本文在一台服务器上做主从实验
主库：172.29.16.24：3306
从库：172.29.16.24：3307

主从库的安装目录分别为/usr/local/mysql3306、/usr/local/mysql3307
主从库的数据目录分别为/data/mysql3306、/data/mysql3307
主从库的登录密码都为123456

两个实例的my.cnf里不一样的配置部分
端口不一样！另外：server-id一定不能一样，最好用端口号来标明server-id，一个是3306，一个是3307
其他内容配置一样，主库一定要开启binlog日志功能，从库可以开启，也可以不开启）
[root@radius01 ~]# cat /usr/local/mysql3306/my.cnf |grep mysql3306
socket = /usr/local/mysql3306/var/mysql.sock
socket = /usr/local/mysql3306/var/mysql.sock
basedir = /usr/local/mysql3306/
datadir = /data/mysql3306/data
pid-file = /data/mysql3306/data/mysql.pid
log_error = /data/mysql3306/data/mysql-error.log
slow_query_log_file = /data/mysql3306/data/mysql-slow.log

[root@radius01 ~]# cat /usr/local/mysql3307/my.cnf |grep mysql3307
socket = /usr/local/mysql3307/var/mysql.sock
socket = /usr/local/mysql3307/var/mysql.sock
basedir = /usr/local/mysql3307/
datadir = /data/mysql3307/data
pid-file = /data/mysql3307/data/mysql.pid
log_error = /data/mysql3307/data/mysql-error.log
slow_query_log_file = /data/mysql3307/data/mysql-slow.log

注意分别授权
[root@radius01 ~]# chown -R mysql.mysql /usr/local/mysql3306
[root@radius01 ~]# chown -R mysql.mysql /usr/local/mysql3307
[root@radius01 ~]# chown -R mysql.mysql /data/mysql3306/
[root@radius01 ~]# chown -R mysql.mysql /data/mysql3307

启动主从库
[root@radius01 ~]# nohup /usr/local/mysql3306/bin/mysqld_safe --datadir=/data/mysql3306/data --pid-file=/data/mysql3306/data/mysql.pid &
[root@radius01 ~]# nohup /usr/local/mysql3307/bin/mysqld_safe --datadir=/data/mysql3307/data --pid-file=/data/mysql3307/data/mysql.pid &
[root@radius01 ~]# lsof -i:3306
COMMAND   PID  USER   FD   TYPE DEVICE SIZE/OFF NODE NAME
mysqld  28617 mysql   19u  IPv4 838860      0t0  TCP *:mysql (LISTEN)
[root@radius01 ~]# lsof -i:3307
COMMAND   PID  USER   FD   TYPE DEVICE SIZE/OFF NODE NAME
mysqld  29538 mysql   19u  IPv4 839401      0t0  TCP *:opsession-prxy (LISTEN)

注意，当一台服务器上安装了多个实例的mysql的时候，直接登录mysql的时候，记住要在登录命令中跟上对应的sock路径，如下：
[root@radius01 ~]# /usr/local/mysql3306/bin/mysql -p123456 -S /usr/local/mysql3306/var/mysql.sock
......
mysql> select @@port;
+--------+
| @@port |
+--------+
|   3306 |
+--------+
1 row in set (0.00 sec)

[root@radius01 ~]# /usr/local/mysql3307/bin/mysql -p123456 -S /usr/local/mysql3307/var/mysql.sock
......
mysql> select @@port;
+--------+
| @@port |
+--------+
|   3307 |
+--------+
1 row in set (0.00 sec)
------------------------------------------------------------------------------------------------------------------------
如果不跟上对应的sock路径，直接登录的话会报错：
[root@radius01 ~]# /usr/local/mysql3306/bin/mysql -p123456
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock'
这样，如果你如下做软链接：
[root@radius01 ~]# ln -s /usr/local/mysql3306/var/mysql.sock /var/lib/mysql/mysql.sock
或者
[root@radius01 ~]# ln -s /usr/local/mysql3307/var/mysql.sock /var/lib/mysql/mysql.sock

那么这样操作之后，无论是登录3306端口的mysql，还是登录3307端口的mysql，里面的操作都是一样的，即这样就分不清两个端口的mysql实例了！
所以还是在登录各个端口的mysql实例时要跟上对应的sock路径！

2）部署主从复制环境
先在主库上操作：
[root@radius01 ~]# /usr/local/mysql3306/bin/mysql -p123456 -S /usr/local/mysql3306/var/mysql.sock
......
mysql> GRANT REPLICATION SLAVE ON *.* TO 'repl'@'172.29.16.%' IDENTIFIED BY 'mycatms';
mysql> flush privileges;
mysql> show master status;
+------------------+----------+--------------+------------------+-------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+-------------------+
| mysql-bin.000015 |      199 |              |                  |                   |
+------------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)

接着在从库（即33077端口）上设置主从复制
先在从库上验证下是否能使用授予的权限连接主库
[root@radius01 ~]# /usr/local/mysql3307/bin/mysql -u repl -h 172.29.16.24 -pmycatms -S /usr/local/mysql3306/var/mysql.sock
.....
mysql> select @@port;
+--------+
| @@port |
+--------+
|   3306 |
+--------+
1 row in set (0.00 sec)

然后进行主从复制设置
[root@radius01 ~]# /usr/local/mysql3307/bin/mysql -p123456 -S /usr/local/mysql3307/var/mysql.sock
.......
mysql> select @@port;
+--------+
| @@port |
+--------+
|   3307 |
+--------+
1 row in set (0.00 sec)
mysql> stop slave;
mysql> reset slave;
mysql> change master to master_user='repl', master_password='mycatms', master_host='172.29.16.24',master_port=3306, master_log_file='mysql-bin.000015',master_log_pos=199;
mysql> start slave;
mysql> show slave status \G;
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 172.29.16.24
                  Master_User: repl
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000015
          Read_Master_Log_Pos: 199
               Relay_Log_File: mysql-relay-bin.000002
                Relay_Log_Pos: 283
        Relay_Master_Log_File: mysql-bin.000015
             Slave_IO_Running: Yes
            Slave_SQL_Running: Yes
.......
.......
-------------------------------------------------------------------------------------------------------------------------------------
如果出现下面报错：
Fatal error: The slave I/O thread stops because master and slave have equal MySQL server UUIDs; these UUIDs must be different for replication to work.

原因分析：
mysql 5.6的复制引入了uuid的概念，各个复制结构中的server_uuid得保证不一样，但是查看到直接copy  data文件夹后server_uuid是相同的，show variables like '%server_uuid%';
也就是说：
我的实验环境中的3306端口的mysql实例和3307端口的mysql实例的uuid是一样的导致的，因为我是直接复制的data数据目录。如下查看：
[root@radius01 ~]# /usr/local/mysql3306/bin/mysql -p123456 -S /usr/local/mysql3306/var/mysql.sock
.........
mysql> show variables like '%server_uuid%';
+---------------+--------------------------------------+
| Variable_name | Value                                |
+---------------+--------------------------------------+
| server_uuid   | 5509fe69-96b6-11e7-aef5-aaafa07a2e23 |
+---------------+--------------------------------------+
1 row in set (0.00 sec)

[root@radius01 ~]# /usr/local/mysql3307/bin/mysql -p123456 -S /usr/local/mysql3307/var/mysql.sock
......
mysql> show variables like '%server_uuid%';
+---------------+--------------------------------------+
| Variable_name | Value                                |
+---------------+--------------------------------------+
| server_uuid   | 5509fe69-96b6-11e7-aef5-aaafa07a2e23 |
+---------------+--------------------------------------+
1 row in set (0.00 sec)

解决办法：
找到3306端口和3307端口的data文件夹下的auto.cnf文件，直接删除掉，然后重启各自的mysql即可！重启后，可以再次生成auto.conf文件（重新生成后的uuid就不一样了）
[root@radius01 ~]# rm -rf /data/mysql3306/data/auto.cnf
[root@radius01 ~]# rm -rf /data/mysql3307/data/auto.cnf
[root@radius01 ~]# nohup /usr/local/mysql3306/bin/mysqld_safe --datadir=/data/mysql3306/data --pid-file=/data/mysql3306/data/mysql.pid &
[root@radius01 ~]# nohup /usr/local/mysql3307/bin/mysqld_safe --datadir=/data/mysql3307/data --pid-file=/data/mysql3307/data/mysql.pid &
[root@radius01 ~]# cat /data/mysql3306/data/auto.cnf
[auto]
server-uuid=f6a726d2-96fd-11e7-b0c8-aaafa07a2e23
[root@radius01 ~]# cat /data/mysql3307/data/auto.cnf
[auto]
server-uuid=fc6ee68c-96fd-11e7-b0c8-aaafa07a2e23
-------------------------------------------------------------------------------------------------------------------------------------

数据同步测试：
在主库里写入新数据
[root@radius01 ~]# /usr/local/mysql3306/bin/mysql -p123456 -S /usr/local/mysql3306/var/mysql.sock
mysql> create database wangshibo;
mysql> use wangshibo;
mysql> create table tehui(
    -> id int not null primary key,
    -> name varchar(10));
mysql> insert into tehui values(1,"huanhuan");
mysql> insert into tehui values(11,"meimei");
mysql> select * from tehui;
+----+----------+
| id | name     |
+----+----------+
|  1 | huanhuan |
| 11 | meimei   |
+----+----------+
2 rows in set (0.00 sec)

在从库查看是否已同步
[root@radius01 ~]# /usr/local/mysql3307/bin/mysql -p123456 -S /usr/local/mysql3307/var/mysql.sock
mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| test               |
| wangshibo          |
+--------------------+
5 rows in set (0.00 sec)

mysql> use wangshibo;
mysql> show tables;
+---------------------+
| Tables_in_wangshibo |
+---------------------+
| tehui               |
+---------------------+
1 row in set (0.00 sec)

mysql> select * from tehui;
+----+----------+
| id | name     |
+----+----------+
|  1 | huanhuan |
| 11 | meimei   |
+----+----------+
2 rows in set (0.00 sec)