04 mysql主从复制架构及实现

实战：主主复制

[root@master ~]# systemctl stop mariadb.service 

[root@slave ~]# systemctl stop mariadb.service

[root@master ~]# rm -rf /var/lib/mysql/*

[root@slave ~]# rm -rf /var/lib/mysql/*

[root@master ~]# vim /etc/my.cnf

添加

log-bin=master-bin

relay_log=relay-log

server-id=1

innodb_file_per_table=ON

skip_name_resolve=ON

auto_increment_offset=1

auto_increment_increment=2

[root@slave ~]# vim /etc/my.cnf

添加

log-bin=master-bin

relay_log=relay-log

server-id=5

innodb_file_per_table=ON

skip_name_resolve=ON

auto_increment_offset=2

auto_increment_increment=2

[root@master ~]# systemctl start mariadb.service 

[root@master ~]# mysql

#确保relay_log值为relay-log

MariaDB [(none)]> SHOW GLOBAL VARIABLES LIKE ‘relay_log‘;

+---------------+-----------+

| Variable_name | Value     |

+---------------+-----------+

| relay_log     | relay-log |

+---------------+-----------+

#确保log_bin值为ON

MariaDB [(none)]> SHOW GLOBAL VARIABLES LIKE ‘log_bin‘;

+---------------+-------+

| Variable_name | Value |

+---------------+-------+

| log_bin       | ON    |

+---------------+-------+

[root@slave ~]# systemctl start mariadb.service 

[root@slave ~]# mysql

#确保relay_log值为relay-log

MariaDB [(none)]> SHOW GLOBAL VARIABLES LIKE ‘relay_log‘;

+---------------+-----------+

| Variable_name | Value     |

+---------------+-----------+

| relay_log     | relay-log |

+---------------+-----------+

#确保log_bin值为ON

MariaDB [(none)]> SHOW GLOBAL VARIABLES LIKE ‘log_bin‘;

+---------------+-------+

| Variable_name | Value |

+---------------+-------+

| log_bin       | ON    |

+---------------+-------+

#主节点

MariaDB [(none)]> GRANT REPLICATION SLAVE,REPLICATION CLIENT ON *.* TO ‘repluser‘@‘192.168.%.%‘ IDENTIFIED BY ‘replpass‘;

MariaDB [(none)]> FLUSH PRIVILEGES;

MariaDB [(none)]> SHOW MASTER STATUS;

+-------------------+----------+--------------+------------------+

| File              | Position | Binlog_Do_DB | Binlog_Ignore_DB |

+-------------------+----------+--------------+------------------+

| master-bin.000003 |      507 |              |                  |

+-------------------+----------+--------------+------------------+

MariaDB [(none)]> CHANGE MASTER TO MASTER_HOST=‘192.168.1.132‘,MASTER_USER=‘repluser‘,MASTER_PASSWORD=‘replpass‘,MASTER_LOG_FILE=‘master-bin.000003‘,MASTER_LOG_POS=507;

MariaDB [(none)]> SHOW SLAVE STATUS \G

*************************** 1. row ***************************

  Slave_IO_State: 

 Master_Host: 192.168.1.132

 Master_User: repluser

 Master_Port: 3306

Connect_Retry: 60

 Master_Log_File: master-bin.000003

 Read_Master_Log_Pos: 507

  Relay_Log_File: relay-log.000001

Relay_Log_Pos: 4

Relay_Master_Log_File: master-bin.000003

MariaDB [(none)]> START SLAVE;

Query OK, 0 rows affected (0.00 sec)

MariaDB [(none)]> SHOW SLAVE STATUS \G

*************************** 1. row ***************************

  Slave_IO_State: Waiting for master to send event

 Master_Host: 192.168.1.132

 Master_User: repluser

 Master_Port: 3306

Connect_Retry: 60

 Master_Log_File: master-bin.000003

 Read_Master_Log_Pos: 507

  Relay_Log_File: relay-log.000002

Relay_Log_Pos: 530

Relay_Master_Log_File: master-bin.000003

Slave_IO_Running: Yes

Slave_SQL_Running: Yes

#从节点

MariaDB [(none)]> GRANT REPLICATION SLAVE,REPLICATION CLIENT ON *.* TO ‘repluser‘@‘192.168.%.%‘ IDENTIFIED BY ‘replpass‘;

MariaDB [(none)]> FLUSH PRIVILEGES;

MariaDB [(none)]> SHOW MASTER STATUS;

+-------------------+----------+--------------+------------------+

| File              | Position | Binlog_Do_DB | Binlog_Ignore_DB |

+-------------------+----------+--------------+------------------+

| master-bin.000003 |      507 |              |                  |

+-------------------+----------+--------------+------------------+

MariaDB [(none)]> CHANGE MASTER TO MASTER_HOST=‘192.168.1.131‘,MASTER_USER=‘repluser‘,MASTER_PASSWORD=‘replpass‘,MASTER_LOG_FILE=‘master-bin.000003‘,MASTER_LOG_POS=507;

MariaDB [(none)]> SHOW SLAVE STATUS \G                               _USER=‘repluser‘,MASTER_PASSWORD=‘replpass‘,MASTER_LOG_FILE=‘master-bin.000003‘,

*************************** 1. row ***************************

  Slave_IO_State: 

 Master_Host: 192.168.1.131

 Master_User: repluser

 Master_Port: 3306

Connect_Retry: 60

 Master_Log_File: master-bin.000003

 Read_Master_Log_Pos: 507

  Relay_Log_File: relay-log.000001

Relay_Log_Pos: 4

Relay_Master_Log_File: master-bin.000003

Slave_IO_Running: No

Slave_SQL_Running: No

MariaDB [(none)]> START SLAVE;

Query OK, 0 rows affected (0.00 sec)

MariaDB [(none)]> SHOW SLAVE STATUS \G

*************************** 1. row ***************************

  Slave_IO_State: Waiting for master to send event

 Master_Host: 192.168.1.131

 Master_User: repluser

 Master_Port: 3306

Connect_Retry: 60

 Master_Log_File: master-bin.000003

 Read_Master_Log_Pos: 507

  Relay_Log_File: relay-log.000002

Relay_Log_Pos: 530

Relay_Master_Log_File: master-bin.000003

Slave_IO_Running: Yes

Slave_SQL_Running: Yes

测试1：主结点创建一个数据库mydb

#主节点

MariaDB [(none)]> CREATE DATABASE mydb;

MariaDB [(none)]> SHOW SLAVE STATUS \G 

*************************** 1. row ***************************

  Slave_IO_State: Waiting for master to send event

 Master_Host: 192.168.1.132

 Master_User: repluser

 Master_Port: 3306

Connect_Retry: 60

 Master_Log_File: master-bin.000003

 Read_Master_Log_Pos: 507

  Relay_Log_File: relay-log.000002

Relay_Log_Pos: 530

Relay_Master_Log_File: master-bin.000003

Slave_IO_Running: Yes

Slave_SQL_Running: Yes

#从结点：

MariaDB [(none)]> SHOW SLAVE STATUS \G

*************************** 1. row ***************************

  Slave_IO_State: Waiting for master to send event

 Master_Host: 192.168.1.131

 Master_User: repluser

 Master_Port: 3306

Connect_Retry: 60

 Master_Log_File: master-bin.000003

 Read_Master_Log_Pos: 595

  Relay_Log_File: relay-log.000002

Relay_Log_Pos: 618

Relay_Master_Log_File: master-bin.000003

Slave_IO_Running: Yes

Slave_SQL_Running: Yes

MariaDB [(none)]> SHOW DATABASES;

+--------------------+

| Database           |

+--------------------+

| information_schema |

| mydb               |

| mysql              |

| performance_schema |

| test               |

+--------------------+

结果：从节点已复制主节点的数据库

测试2：从结点在主节点创建的数据库mydb中创建数据表tb1

#从结点：

MariaDB [(none)]> USE mydb;

Database changed

MariaDB [mydb]> CREATE TABLE tb1 (id INT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY,name CHAR(30));

MariaDB [mydb]> DESC tb1;

+-------+------------------+------+-----+---------+----------------+

| Field | Type             | Null | Key | Default | Extra          |

+-------+------------------+------+-----+---------+----------------+

| id    | int(10) unsigned | NO   | PRI | NULL    | auto_increment |

| name  | char(30)         | YES  |     | NULL    |                |

+-------+------------------+------+-----+---------+----------------+

MariaDB [mydb]> SHOW MASTER STATUS;

+-------------------+----------+--------------+------------------+

| File              | Position | Binlog_Do_DB | Binlog_Ignore_DB |

+-------------------+----------+--------------+------------------+

| master-bin.000003 |      659 |              |                  |

+-------------------+----------+--------------+------------------+

#主结点

MariaDB [(none)]> SHOW SLAVE STATUS \G

*************************** 1. row ***************************

  Slave_IO_State: Waiting for master to send event

 Master_Host: 192.168.1.132

 Master_User: repluser

 Master_Port: 3306

Connect_Retry: 60

 Master_Log_File: master-bin.000003

 Read_Master_Log_Pos: 659

  Relay_Log_File: relay-log.000002

Relay_Log_Pos: 682

Relay_Master_Log_File: master-bin.000003

Slave_IO_Running: Yes

Slave_SQL_Running: Yes

MariaDB [(none)]> use mydb;

MariaDB [mydb]> SHOW TABLES;

+----------------+

| Tables_in_mydb |

+----------------+

| tb1            |

+----------------+

1 row in set (0.00 sec)

MariaDB [mydb]> DESC tb1;

+-------+------------------+------+-----+---------+----------------+

| Field | Type             | Null | Key | Default | Extra          |

+-------+------------------+------+-----+---------+----------------+

| id    | int(10) unsigned | NO   | PRI | NULL    | auto_increment |

| name  | char(30)         | YES  |     | NULL    |                |

+-------+------------------+------+-----+---------+----------------+

MariaDB [mydb]> INSERT INTO tb1 (name) VALUES(‘Yang Kang‘),(‘Yang Guo‘),(‘Yang Yanzhao‘);MariaDB [mydb]> SELECT * FROM tb1;

+----+--------------+

| id | name         |

+----+--------------+

|  1 | Yang Kang    |

|  3 | Yang Guo     |

|  5 | Yang Yanzhao |

+----+--------------+

#从结点

MariaDB [mydb]> SELECT * FROM tb1;

+----+--------------+

| id | name         |

+----+--------------+

|  1 | Yang Kang    |

|  3 | Yang Guo     |

|  5 | Yang Yanzhao |

+----+--------------+

MariaDB [mydb]> INSERT INTO tb1 (name) VALUES(‘Zhu Yuanzhang‘),(‘Zhu Di‘),(‘Zhu Yue‘);

MariaDB [mydb]>  SELECT * FROM tb1;

+----+---------------+

| id | name          |

+----+---------------+

|  1 | Yang Kang     |

|  3 | Yang Guo      |

|  5 | Yang Yanzhao  |

|  6 | Zhu Yuanzhang |

|  8 | Zhu Di        |

| 10 | Zhu Yue       |

+----+---------------+

#主节点

MariaDB [mydb]> SELECT * FROM tb1;

+----+---------------+

| id | name          |

+----+---------------+

|  1 | Yang Kang     |

|  3 | Yang Guo      |

|  5 | Yang Yanzhao  |

|  6 | Zhu Yuanzhang |

|  8 | Zhu Di        |

| 10 | Zhu Yue       |

+----+---------------+

MariaDB [mydb]> INSERT INTO tb1 (name) VALUES(‘Mao Ze‘);

Query OK, 1 row affected (0.02 sec)

MariaDB [mydb]> SELECT * FROM tb1;                      

+----+---------------+

| id | name          |

+----+---------------+

|  1 | Yang Kang     |

|  3 | Yang Guo      |

|  5 | Yang Yanzhao  |

|  6 | Zhu Yuanzhang |

|  8 | Zhu Di        |

| 10 | Zhu Yue       |

| 11 | Mao Ze        |

+----+---------------+

测试结果：主节点从从结点同步数据成功

实战：半同步复制

[root@master ~]# systemctl stop mariadb.service 

[root@slave ~]# systemctl stop mariadb.service

[root@master ~]# rm -rf /var/lib/mysql/*

[root@slave ~]# rm -rf /var/lib/mysql/*

[root@master ~]# vim /etc/my.cnf

添加

log-bin=master-bin

server-id=1

innodb_file_per_table=ON

skip_name_resolve=ON

[root@slave ~]# vim /etc/my.cnf

添加

relay_log=relay-log

server-id=5

innodb_file_per_table=ON

skip_name_resolve=ON

[root@slave ~]# systemctl start mariadb.service

[root@master ~]# systemctl start mariadb.service 

#主服务器

[root@master ~]# mysql

MariaDB [(none)]> GRANT REPLICATION SLAVE,REPLICATION CLIENT ON *.* TO ‘repluser‘@‘192.168.%.%‘ IDENTIFIED BY ‘replpass‘;

MariaDB [(none)]> FLUSH PRIVILEGES;

MariaDB [(none)]> SHOW MASTER STATUS;

+-------------------+----------+--------------+------------------+

| File              | Position | Binlog_Do_DB | Binlog_Ignore_DB |

+-------------------+----------+--------------+------------------+

| master-bin.000003 |      497 |              |                  |

+-------------------+----------+--------------+------------------+

#从服务器

[root@slave ~]# mysql

MariaDB [(none)]> CHANGE MASTER TO MASTER_HOST=‘192.168.1.131‘,MASTER_USER=‘repluser‘,MASTER_PASSWORD=‘replpass‘,MASTER_LOG_FILE=‘master-bin.000003‘,MASTER_LOG_POS=497;

MariaDB [(none)]> START SLAVE;                                       _USER=‘repluser‘,MASTER_PASSWORD=‘replpass‘,MASTER_LOG_FILE=‘master-bin.000003‘,

Query OK, 0 rows affected (0.01 sec)

MariaDB [(none)]> SHOW SLAVE STATUS \G

*************************** 1. row ***************************

  Slave_IO_State: Waiting for master to send event

 Master_Host: 192.168.1.131

 Master_User: repluser

 Master_Port: 3306

Connect_Retry: 60

 Master_Log_File: master-bin.000003

 Read_Master_Log_Pos: 497

  Relay_Log_File: relay-log.000002

Relay_Log_Pos: 530

Relay_Master_Log_File: master-bin.000003

Slave_IO_Running: Yes

Slave_SQL_Running: Yes

MariaDB [(none)]> STOP SLAVE;

#主节点

MariaDB [(none)]> INSTALL PLUGIN rpl_semi_sync_master SONAME ‘semisync_master.so‘;

MariaDB [(none)]> SHOW GLOBAL VARIABLES LIKE ‘%semi%‘;

+------------------------------------+-------+

| Variable_name                      | Value |

+------------------------------------+-------+

| rpl_semi_sync_master_enabled       | OFF   |

| rpl_semi_sync_master_timeout       | 10000 |

| rpl_semi_sync_master_trace_level   | 32    |

| rpl_semi_sync_master_wait_no_slave | ON    |

+------------------------------------+-------+

MariaDB [(none)]> SHOW GLOBAL STATUS LIKE ‘%semi%‘;

+--------------------------------------------+-------+

| Variable_name                              | Value |

+--------------------------------------------+-------+

| Rpl_semi_sync_master_clients               | 0     |

| Rpl_semi_sync_master_net_avg_wait_time     | 0     |

| Rpl_semi_sync_master_net_wait_time         | 0     |

| Rpl_semi_sync_master_net_waits             | 0     |

| Rpl_semi_sync_master_no_times              | 0     |

| Rpl_semi_sync_master_no_tx                 | 0     |

| Rpl_semi_sync_master_status                | OFF   |

| Rpl_semi_sync_master_timefunc_failures     | 0     |

| Rpl_semi_sync_master_tx_avg_wait_time      | 0     |

| Rpl_semi_sync_master_tx_wait_time          | 0     |

| Rpl_semi_sync_master_tx_waits              | 0     |

| Rpl_semi_sync_master_wait_pos_backtraverse | 0     |

| Rpl_semi_sync_master_wait_sessions         | 0     |

| Rpl_semi_sync_master_yes_tx                | 0     |

+--------------------------------------------+-------+

MariaDB [(none)]> SET GLOBAL rpl_semi_sync_master_enabled=1;

MariaDB [(none)]> SHOW GLOBAL VARIABLES LIKE ‘%semi%‘;         

+------------------------------------+-------+

| Variable_name                      | Value |

+------------------------------------+-------+

| rpl_semi_sync_master_enabled       | ON    |

| rpl_semi_sync_master_timeout       | 10000 |

| rpl_semi_sync_master_trace_level   | 32    |

| rpl_semi_sync_master_wait_no_slave | ON    |

+------------------------------------+-------+

#从结点

MariaDB [(none)]> INSTALL PLUGIN rpl_semi_sync_slave SONAME ‘semisync_slave.so‘;

MariaDB [(none)]> SHOW GLOBAL VARIABLES LIKE ‘%semi%‘;

+------------------------------------+-------+

| Variable_name                      | Value |

+------------------------------------+-------+

| rpl_semi_sync_slave_enabled        | OFF   |

| rpl_semi_sync_slave_trace_level    | 32    |

+------------------------------------+-------+

MariaDB [(none)]> SET GLOBAL rpl_semi_sync_slave_enabled=1;

MariaDB [(none)]> SHOW GLOBAL VARIABLES LIKE ‘%semi%‘;     

+------------------------------------+-------+

| Variable_name                      | Value |

+------------------------------------+-------+

| rpl_semi_sync_slave_enabled        | ON    |

| rpl_semi_sync_slave_trace_level    | 32    |

+------------------------------------+-------+

MariaDB [(none)]> START SLAVE;

Query OK, 0 rows affected (0.01 sec)

MariaDB [(none)]> SHOW SLAVE STATUS \G

*************************** 1. row ***************************

  Slave_IO_State: Waiting for master to send event

 Master_Host: 192.168.1.131

 Master_User: repluser

 Master_Port: 3306

Connect_Retry: 60

 Master_Log_File: master-bin.000003

 Read_Master_Log_Pos: 497

  Relay_Log_File: relay-log.000003

Relay_Log_Pos: 530

Relay_Master_Log_File: master-bin.000003

Slave_IO_Running: Yes

Slave_SQL_Running: Yes

#主服务器

MariaDB [(none)]> SHOW GLOBAL STATUS LIKE ‘%semi%‘;         

+--------------------------------------------+-------+

| Variable_name                              | Value |

+--------------------------------------------+-------+

| Rpl_semi_sync_master_clients               | 1     |

| Rpl_semi_sync_master_net_avg_wait_time     | 0     |

| Rpl_semi_sync_master_net_wait_time         | 0     |

| Rpl_semi_sync_master_net_waits             | 0     |

| Rpl_semi_sync_master_no_times              | 0     |

| Rpl_semi_sync_master_no_tx                 | 0     |

| Rpl_semi_sync_master_status                | ON    |

| Rpl_semi_sync_master_timefunc_failures     | 0     |

| Rpl_semi_sync_master_tx_avg_wait_time      | 0     |

| Rpl_semi_sync_master_tx_wait_time          | 0     |

| Rpl_semi_sync_master_tx_waits              | 0     |

| Rpl_semi_sync_master_wait_pos_backtraverse | 0     |

| Rpl_semi_sync_master_wait_sessions         | 0     |

| Rpl_semi_sync_master_yes_tx                | 0     |

+--------------------------------------------+-------+

MariaDB [(none)]> CREATE DATABASE mydb;

Query OK, 1 row affected (0.01 sec)

MariaDB [(none)]> USE mydb;

MariaDB [mydb]> CREATE TABLE tb1 (id int,name char(30));

MariaDB [mydb]> SHOW GLOBAL STATUS LIKE ‘%semi%‘;

+--------------------------------------------+-------+

| Variable_name                              | Value |

+--------------------------------------------+-------+

| Rpl_semi_sync_master_clients               | 1     |

| Rpl_semi_sync_master_net_avg_wait_time     | 1759  |

| Rpl_semi_sync_master_net_wait_time         | 3518  |

| Rpl_semi_sync_master_net_waits             | 2     |

| Rpl_semi_sync_master_no_times              | 0     |

| Rpl_semi_sync_master_no_tx                 | 0     |

| Rpl_semi_sync_master_status                | ON    |

| Rpl_semi_sync_master_timefunc_failures     | 0     |

| Rpl_semi_sync_master_tx_avg_wait_time      | 2437  |

| Rpl_semi_sync_master_tx_wait_time          | 4875  |

| Rpl_semi_sync_master_tx_waits              | 2     |

| Rpl_semi_sync_master_wait_pos_backtraverse | 0     |

| Rpl_semi_sync_master_wait_sessions         | 0     |

| Rpl_semi_sync_master_yes_tx                | 2     |

+--------------------------------------------+-------+

实战：复制过滤器

#从服务器

MariaDB [(none)]> SHOW GLOBAL VARIABLES LIKE ‘replicate%‘;

+----------------------------------+-----------+

| Variable_name                    | Value     |

+----------------------------------+-----------+

| replicate_annotate_row_events    | OFF       |

| replicate_do_db                  |           |

| replicate_do_table               |           |

| replicate_events_marked_for_skip | replicate |

| replicate_ignore_db              |           |

| replicate_ignore_table           |           |

| replicate_wild_do_table          |           |

| replicate_wild_ignore_table      |           |

+----------------------------------+-----------+

MariaDB [(none)]> STOP SLAVE;

MariaDB [(none)]> SET GLOBAL replicate_do_db=mydb;  

MariaDB [(none)]> SHOW GLOBAL VARIABLES LIKE ‘replicate%‘;

+----------------------------------+-----------+

| Variable_name                    | Value     |

+----------------------------------+-----------+

| replicate_annotate_row_events    | OFF       |

| replicate_do_db                  | mydb      |

| replicate_do_table               |           |

| replicate_events_marked_for_skip | replicate |

| replicate_ignore_db              |           |

| replicate_ignore_table           |           |

| replicate_wild_do_table          |           |

| replicate_wild_ignore_table      |           |

+----------------------------------+-----------+

MariaDB [(none)]> START SLAVE;

Query OK, 0 rows affected (0.00 sec)

MariaDB [(none)]> SHOW SLAVE STATUS \G

*************************** 1. row ***************************

  Slave_IO_State: Waiting for master to send event

 Master_Host: 192.168.1.131

 Master_User: repluser

 Master_Port: 3306

Connect_Retry: 60

 Master_Log_File: master-bin.000003

 Read_Master_Log_Pos: 682

  Relay_Log_File: relay-log.000004

Relay_Log_Pos: 530

Relay_Master_Log_File: master-bin.000003

Slave_IO_Running: Yes

Slave_SQL_Running: Yes

 Replicate_Do_DB: mydb

#主服务器

MariaDB [mydb]> CREATE DAMariaDB [mydb]> SHOW DATABASES;

+--------------------+

| Database           |

+--------------------+

| information_schema |

| mydb               |

| mysql              |

| performance_schema |

| test               |

| testdb             |

+--------------------+

#从服务器

MariaDB [(none)]> SHOW DATABASES;

+--------------------+

| Database           |

+--------------------+

| information_schema |

| mydb               |

| mysql              |

| performance_schema |

| test               |

+--------------------+

#主服务器

MariaDB [mydb]> INSERT INTO tb1 VALUES (1,"a");

#从服务器

MariaDB [(none)]> USE mydb;

MariaDB [mydb]> SELECT * FROM tb1;

+------+------+

| id   | name |

+------+------+

|    1 | a    |

+------+------+

实战：清理mysql日志

MariaDB [mydb]> SHOW BINARY LOGS;

+-------------------+-----------+

| Log_name          | File_size |

+-------------------+-----------+

| master-bin.000001 |     30334 |

| master-bin.000002 |   1038814 |

| master-bin.000003 |       957 |

+-------------------+-----------+

MariaDB [mydb]> PURGE BINARY LOGS TO ‘master-bin.000002‘;

MariaDB [mydb]> SHOW BINARY LOGS;                        

+-------------------+-----------+

| Log_name          | File_size |

+-------------------+-----------+

| master-bin.000002 |   1038814 |

| master-bin.000003 |       957 |

+-------------------+-----------+

MariaDB [mydb]> PURGE BINARY LOGS TO ‘master-bin.000003‘;

Query OK, 0 rows affected (0.02 sec)

MariaDB [mydb]> SHOW BINARY LOGS;                        

+-------------------+-----------+

| Log_name          | File_size |

+-------------------+-----------+

| master-bin.000003 |       957 |

+-------------------+-----------+

[root@master ~]# ls /var/lib/mysql/

aria_log.00000001  ib_logfile1        mysql               testdb

aria_log_control   master-bin.000003  mysql.sock

ibdata1            master-bin.index   performance_schema

ib_logfile0        mydb               test

注意：日志清理后，其对应的文件也会被删除

本文出自 “追梦” 博客，请务必保留此出处http://sihua.blog.51cto.com/377227/1875526

42-4 mysql主从复制