实验环境;

两台centos7主机，一台ip为10.10.251.49 作为master

一台ip为10.10.251.59作为slave(复制上台虚拟机，需要修改ip，还有mysql数据库的uuid)

主从同步原理图

1)，master需要开启bin-log，用于记录主库修改数据库的SQL语句。

2)，异步复制过程，毫秒延迟(磁盘io，网速影响)，需要开启3个线程，master开启IO线程，slave开启IO线程，SQL线程

3)，从库启动salve start，通过IO线程，用户名和密码去连接 MASTER，MASTER IO线程，负责将bin-log内容，Position位置点数据发给SLAVE。

4)，SLAVE IO 线程收到数据后，会将内容追加到本地 relay-log 中继日志，同时生成master.info 文件(用户名，密码，bin-log，)

二：

1)安装mysql

wget http://dev.mysql.com/get/mysql57-community-release-el7-7.noarch.rpm从 下载yum源

yum localinstall mysql57-community-release-el7-7.noarch.rpm 安装yum源

yum install mysql mysql-server mysql-devel -y

2)编辑myql默认配置文件，

vi /etc/my.cnf

添加以下内容

log-bin=mysql-bin

server-id= 1

systemctl restart mysqld 重启数据库

3)MASTER授权从库访问

mysql -uroot -pzabbix

mysql>  grant replication slave on *.* to 'zabbix'@'10.10.251.65' identified by 'zabbix';  #授权用户名为zabbix，密码为zabbix的用户访问 (一定确认用户名，密码，ip地址正确)

Query OK, 0 rows affected, 1 warning (0.02 sec)

mysql> FLUSH PRIVILEGES; (刷新授权)

Query OK, 0 rows affected (0.01 sec)

mysql> show global variables like '%log%';

确认 为 on

| log_bin | ON |

mysql> show MAster LOGs;(先记录log_name (master主机上的日志名字) 和 File_size(开始同步时候的节点))

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

| Log_name | File_size |

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

| mysql-bin.000001 | 1125905 |

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

1 row in set (0.00 sec)

三，SLAVE库配置

vi /etc/my.cnf

添加以下内容

server-id= 2

relay-log=relay-log

relay-log-index=relay-log.index

systemctl restart mysqld    重启数据库

mysql -uroot -pzabbix

mysql> CHANGE MASTER TO MASTER_HOST='10.10.251.49',MASTER_USER='zabbix',MASTER_PASSWORD='zabbix', MASTER_LOG_FILE='mysql-bin.000001',MASTER_LOG_POS=881468;

Query OK, 0 rows affected, 2 warnings (0.43 sec)  ##需要指定的master的ip，LOG_FILE，LOG_POS，

mysql> start slave;

Query OK, 0 rows affected (0.03 sec)

mysql> show slave status\G

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

Slave_IO_State: Waiting for master to send event

Master_Host: 10.10.251.49

Master_User: zabbix

Master_Port: 3306

Connect_Retry: 60

Master_Log_File: mysql-bin.000001

Read_Master_Log_Pos: 1127135

Relay_Log_File: relay-log.000002

Relay_Log_Pos: 245987

Relay_Master_Log_File: mysql-bin.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: 1127135

Relay_Log_Space: 246188

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: 0

Master_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: 1

Master_UUID: 2c5af6b7-73a1-11e8-8798-a20c9f0a7fef

Master_Info_File: /var/lib/mysql/master.info

SQL_Delay: 0

SQL_Remaining_Delay: NULL

Slave_SQL_Running_State: Slave has read all relay log; waiting for more updates

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: 0

Replicate_Rewrite_DB:

Channel_Name:

Master_TLS_Version:

1 row in set (0.00 sec)

最后测试数据库

master1上

mysql> create database test;

Query OK, 1 row affected (0.01 sec)

mysql> show databases;

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

| Database |

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

| information_schema |

| mysql |

| performance_schema |

| sys |

| test |

| zabbix |

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

6 rows in set (0.00 sec)

slave上

mysql> show databases;

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

| Database |

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

| information_schema |

| mysql |

| performance_schema |

| sys |

| test |

| zabbix |

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

6 rows in set (0.00 sec)

本次搭建测试成功

一：

本次遇到的错误，复制主机后mysql的UUID没改

Last_IO_Errno: 0

Last_IO_Error:

这儿就出现关于uuid的错误，需要在数据库目录下

(我的是/var/lib/mysql/)

vi auto.cfg

删除

server-uuid=2c5af6b7-73a1-11e8-8798-a20c9f0a7fef

并且重启mysqld，会生成新的uuid

二，

SLAVE上多次写入MASTER的信息；

导致数据库总无法 start  slave；

需要 reset slave all；

重新重新绑定主机，

mysql> CHANGE MASTER TO MASTER_HOST='10.10.251.49',MASTER_USER='zabbix',MASTER_PASSWORD='zabbix', MASTER_LOG_FILE='mysql-bin.000001',MASTER_LOG_POS=881468;

方可start slave；

本次参考B站京峰教育视频、