二十七节课预习

17.1 MySQL主从介绍
17.2 准备工作
17.3 配置主
17.4 配置从
17.5 测试主从同步

有的同学，遇到主从不能正常同步，提示uuid相同的错误。这是因为克隆机器导致。
https://www.2cto.com/database/201412/364479.html

扩展部分
不停库不锁表在线主从配置
http://seanlook.com/2015/12/14/mysql-replicas/
主从不同步
http://www.rfyy.net/archives/2309.html
http://blog.51cto.com/storysky/259280
主主
关于 auto_increment  https://blog.csdn.net/leshami/article/details/39779509
http://www.cnblogs.com/ygqygq2/p/6045279.html
mysql-proxy 实现读写分离 
http://blog.51cto.com/zzclinux/1980487
mysql-proxy类似的产品有：
mycat  基于阿里的开源软件cobar，官网 www.mycat.io 
https://my.oschina.net/ruoli/blog/1789370
mycat实现分库分表  
https://www.cnblogs.com/joylee/p/7513038.html
atlas   出自于360，不维护不更新了  https://blog.csdn.net/AnPHPer/article/details/80566385
mysql环形主从
http://ask.apelearn.com/question/11437
mysql架构演变 http://www.aminglinux.com/bbs/thread-8025-1-1.html
MHA架构 
http://blog.51cto.com/xiaoshuaigege/2060768
比较复杂的mysql集群架构 http://ask.apelearn.com/question/17026

MySQL主从介绍

MySQL主从又叫做Replication、AB复制。简单讲就是A和B两台机器做主从后，在A上写数据，另外一台B也会跟着写数据，两者数据实时同步的

MySQL主从是基于binlog的，主上须开启binlog才能进行主从。主从过程大致有3个步骤

1）主将更改操作记录到binlog里

2）从将主的binlog事件(sql语句)同步到从本机上并记录在relaylog里

3）从根据relaylog里面的sql语句按顺序执行

主上有一个log dump线程，用来和从的I/O线程传递binlog

从上有两个线程，其中I/O线程用来同步主的binlog并生成relaylog，另外一个SQL线程用来把relaylog里面的sql语句落地

主从复制原理图：

 

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二、 准备工作

实现MySQL主从复制需要进行的配置：

主服务器：

开启二进制日志

配置唯一的server-id

获得master二进制日志文件名及位置

创建一个用于slave和master通信的用户账号

从服务器：

配置唯一的server-id

使用master分配的用户账号读取master二进制日志

启用slave服务

主从数据库版本最好一致

主从数据库内数据保持一致

环境准备：

主数据库：mysql-master 192.168.253.143 /Centos7.4 3.10.0-693.el7.x86_64 mysql-5.6.36

从数据库：mysql-slave 192.168.253.144 /Centos7.4 3.10.0-693.el7.x86_64 mysql-5.6.36

三、 配置主

1.编辑/etc/my.cnf配置文件

[root@mysql-master ~]# vim /etc/my.cnf//修改如下字段

server_id = 210

log_bin=master_bin_log//重启服务

[root@mysql-master ~]# /etc/init.d/mysqld restart

Shutting down MySQL.. SUCCESS!

Starting MySQL.. SUCCESS!

[root@mysql-master ~]# ls /data/mysql/

auto.cnf  ib_logfile0  localhost.localdomain.err  master_bin_log.index  mysql-master.err  performance_schema

ibdata1   ib_logfile1  master_bin_log.000001      mysql                 mysql-master.pid  test

2.创建测试库及数据

[root@mysql-master ~]# mysql -uroot

 

 

mysql> create database ms_test;

Query OK, 1 row affected (0.00 sec)

 

mysql> use ms_test;

Database changed

mysql> create table tb1(`id` int(4),`name` char(40));

Query OK, 0 rows affected (0.13 sec)

 

mysql> insert into tb1 values(1,'long');

Query OK, 1 row affected (0.00 sec)

 

mysql> insert into tb1 values(2,'oooo');

Query OK, 1 row affected (0.01 sec)

 

mysql> insert into tb1 values(3,'ccc');

Query OK, 1 row affected (0.00 sec)

 

//备份测试数据库

[root@mysql-master ~]# mysqldump -uroot ms_test > ms_test.sql

3.创建同步数据帐户

mysql> grant replication slave on *.* to 'ms_user'@'192.168.253.143' identified by '123456';

Query OK, 0 rows affected (0.00 sec)

 

mysql> show grants for 'ms_user'@'192.168.253.143';  

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

| Grants for [email protected]                                                                                               |

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

| GRANT REPLICATION SLAVE ON *.* TO 'ms_user'@'192.168.253.143' IDENTIFIED BY PASSWORD '*6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9' |

+----------------------------------------------------------------------------------------------------------------------------+1 row in set (0.00 sec)

 

//锁定表状态

mysql> flush tables with read lock;

Query OK, 0 rows affected (0.00 sec)

 

//显示主状态

mysql> show master status;

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

| File                  | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |

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

| master_bin_log.000001 |     1240 |              |                  |                   |

+-----------------------+----------+--------------+------------------+-------------------+1 row in set (0.00 sec)

 

四、 配置从

1.修改配置文件

[root@mysql-slave ~]# vim /etc/my.cnf//修改如下内容

server_id = 220

[root@mysql-slave ~]# /etc/init.d/mysqld restart

Shutting down MySQL.. SUCCESS!

Starting MySQL.. SUCCESS!

[root@mysql-slave ~]#

2.将主上备份的测试数据库复制到从库并恢复

//在主上执行

[root@mysql-master ~]# scp ms_test.sql [email protected]:/root

The authenticity of host '192.168.253.143 (192.168.253.143)' can't be established.

ECDSA key fingerprint is SHA256:zx1ETx0EY8r1LzVAx806KJRBjPOnR/b3vss7sp1y6Hs.

ECDSA key fingerprint is MD5:1f:39:43:b7:16:b4:37:b2:15:4d:92:d4:a5:b6:a4:c7.

Are you sure you want to continue connecting (yes/no)? yes

Warning: Permanently added '192.168.253.143' (ECDSA) to the list of known hosts.

[email protected]'s password:

ms_test.sql                                                                                  100% 1842   740.6KB/s   00:00  

//在从上执行

[root@mysql-slave ~]# mv ms_test.sql /data/mysql/

[root@mysql-slave ~]# ls /data/mysql/

auto.cnf  ib_logfile0  localhost.localdomain.err  mysql            mysql-slave.pid     test

ibdata1   ib_logfile1  ms_test.sql                mysql-slave.err  performance_schema

//创建ms_test

[root@mysql-slave ~]# mysql -uroot

Welcome to the MySQL monitor.  Commands end with ; or \g.

Your MySQL connection id is 1

Server version: 5.6.36 MySQL Community Server (GPL)

 

Copyright (c) 2000, 2017, 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> create database ms_test;

Query OK, 1 row affected (0.00 sec)

 

mysql> quit

Bye//恢复ms_test

[root@mysql-slave ~]# mysql -uroot ms_test </data/mysql/ms_test.sql

3.设定同步

//从上执行mysql> stop slave;Query OK, 0 rows affected, 1 warning (0.01 sec)

mysql> change master to master_host='192.168.253.144', master_user='ms_user', master_password='123456', master_log_file='master_bin_log.000001', master_log_pos=1240;Query OK, 0 rows affected, 2 warnings (0.08 sec)

mysql> start slave;Query OK, 0 rows affected (0.00 sec)

//查看从状态

mysql> show slave status\Gmysql> show slave status\G*************************** 1. row ***************************               Slave_IO_State: Waiting for master to send event                  Master_Host: 192.168.253.144                  Master_User: ms_user                  Master_Port: 3306                Connect_Retry: 60              Master_Log_File: master_bin_log.000001          Read_Master_Log_Pos: 1240               Relay_Log_File: mysql-slave-relay-bin.000002                Relay_Log_Pos: 288        Relay_Master_Log_File: master_bin_log.000001             Slave_IO_Running: Yes            Slave_SQL_Running: Yes              Replicate_Do_DB:           Replicate_Ignore_DB:            Replicate_Do_Table:        Replicate_Ignore_Table:       Replicate_Wild_Do_Table:   Replicate_Wild_Ignore_Table:                    Last_Errno: 0                   Last_Error:                  Skip_Counter: 0          Exec_Master_Log_Pos: 1240              Relay_Log_Space: 467              Until_Condition: None               Until_Log_File:                 Until_Log_Pos: 0           Master_SSL_Allowed: No           Master_SSL_CA_File:            Master_SSL_CA_Path:               Master_SSL_Cert:             Master_SSL_Cipher:                Master_SSL_Key:         Seconds_Behind_Master: 0Master_SSL_Verify_Server_Cert: No                Last_IO_Errno: 0                Last_IO_Error:                Last_SQL_Errno: 0               Last_SQL_Error:   Replicate_Ignore_Server_Ids:              Master_Server_Id: 210                  Master_UUID: 060b64b3-899b-11e8-9ed3-000c29609adb             Master_Info_File: /data/mysql/master.info                    SQL_Delay: 0          SQL_Remaining_Delay: NULL      Slave_SQL_Running_State: Slave has read all relay log; waiting for the slave I/O thread to update it           Master_Retry_Count: 86400                  Master_Bind:       Last_IO_Error_Timestamp:      Last_SQL_Error_Timestamp:                Master_SSL_Crl:            Master_SSL_Crlpath:            Retrieved_Gtid_Set:             Executed_Gtid_Set:                 Auto_Position: 01 row in set (0.00 sec)

//主上执行mysql> unlock tables;Query OK, 0 rows affected (0.00 sec)

 

五、 测试主从同步

1.编译主配置文件

[root@mysql-master ~]# vim /etc/my.cnf//设定仅同步ms_test数据库，添加下行

binlog-do-db=ms_test

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

[root@mysql-master ~]# /etc/init.d/mysqld restart

Shutting down MySQL.... SUCCESS!

Starting MySQL.. SUCCESS!

2.在主上插入新的记录

[root@mysql-master ~]# mysql -uroot

Welcome to the MySQL monitor.  Commands end with ; or \g.

Your MySQL connection id is 1

Server version: 5.6.36-log MySQL Community Server (GPL)

 

Copyright (c) 2000, 2017, 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> use ms_test;

Reading table information for completion of table and column names

You can turn off this feature to get a quicker startup with -A

 

Database changed

mysql> show tables;

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

| Tables_in_ms_test |

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

| tb1               |

+-------------------+1 row in set (0.00 sec)

 

mysql> select * from tb1;

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

| id   | name |

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

|    1 | long |

|    2 | oooo |

|    3 | ccc  |

+------+------+3 rows in set (0.00 sec)

 

mysql> insert into tb1 values(4,'dddd');

Query OK, 1 row affected (0.00 sec)

 

mysql> select * from tb1;

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

| id   | name |

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

|    1 | long |

|    2 | oooo |

|    3 | ccc  |

|    4 | dddd |

+------+------+4 rows in set (0.00 sec)

3.在从上查看是否有同步

mysql> use ms_test;

Reading table information for completion of table and column names

You can turn off this feature to get a quicker startup with -A

 

Database changed

mysql> show tables;

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

| Tables_in_ms_test |

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

| tb1               |

+-------------------+1 row in set (0.00 sec)

 

mysql> select * from tb1;

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

| id   | name |

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

|    1 | long |

|    2 | oooo |

|    3 | ccc  |

|    4 | dddd |

+------+------+4 rows in set (0.00 sec)