1、说明：

IP 计算机名 角色
192.168.1.101 MySQL-001 master
192.168.1.102 MySQL-002 slave

系统：CentOS 6. 或 7.
MySQL版本：5.7
mysql安装步骤链接
https://blog.51cto.com/10158955/1926574
注意！根据自己的安装路径不同和数据目录不同而修改！（包括配置文件）
2、master配置文件设置如下

一般mysql配置文件在/etc/my.cnf

(如果找不到的话也有可能在这些目录下：/etc/mysql/my.cnf，/usr/local/mysql/etc/my.cnf，~/.my.cnf)

[root@MySQL-001 ~]# vim /etc/my.cnf
[mysqld]
basedir=/usr/local/mysql
datadir=/data/mysqldata
socket=/tmp/mysql.sock
user=mysql
port=3306

master的配置

server-id=1 # 服务器id (主从必须不一样)
binlog-do-db=employees # 要给从机同步的库
binlog-ignore-db=mysql # 不给从机同步的库(多个写多行)
binlog-ignore-db=information_schema
binlog-ignore-db=performance_schema
binlog-ignore-db=sys
log-bin=mysql-bin # 打开日志(主机需要打开)，这个mysql-bin也可以自定义；
expire_logs_days=90 # 自动清理 90 天前的log文件,可根据需要修改
重启数据库使配置生效：

CentOS 6.：
[root@MySQL-001 ~]# service mysqld restart
[root@MySQL-001 ~]# service mysqld status
SUCCESS! MySQL running (15607)
CentOS 7.：
[root@MySQL-001 ~]# systemctl restart mysqld.service
[root@MySQL-001 ~]# systemctl status mysqld.service
mysqld.service - MySQL Server
Loaded: loaded (/usr/lib/systemd/system/mysqld.service; enabled)
Active: active (running) since 四 2018-05-17 11:42:02 CST; 2h 5min ago
Docs: man:mysqld(8)
http://dev.mysql.com/doc/refman/en/using-systemd.html
Main PID: 29959 (mysqld)
CGroup: /system.slice/mysqld.service
└─29959 /opt/mysql/bin/mysqld --defaults-file=/etc/my.cnf

5月 17 11:42:02 tcloud-118 systemd[1]: Started MySQL Server.

测试log_bin是否成功开启

[root@MySQL-001 ~]# mysql -uroot -p
mysql> show variables like '%log_bin%';
+---------------------------------+---------------------------------+
| Variable_name | Value |
+---------------------------------+---------------------------------+
| log_bin | ON |
| log_bin_basename | /opt/mysql/logs/mysql-bin |
| log_bin_index | /opt/mysql/logs/mysql-bin.index |
| log_bin_trust_function_creators | ON |
| log_bin_use_v1_row_events | OFF |
| sql_log_bin | ON |
+---------------------------------+---------------------------------+
6 rows in set (0.00 sec)

mysql>
可以看到log_bin为ON；
3、master的数据库中建立主从同步账号backup：

backup为用户名，192.168.1.%表示只允许192.168.1网段的客户端连接，123456为密码；

mysql> grant replication slave on . to 'backup'@'192.168.1.%' identified by '123456';
mysql> flush privileges;
mysql> select Host,User,authentication_string from mysql.user;
+--------------+---------------+-------------------------------------------+
| Host | User | authentication_string |
+--------------+---------------+-------------------------------------------+
| localhost | root | 6C362347EBEAA7DF44F6D34884615A35095E80EB |
| localhost | mysql.session | THISISNOTAVALIDPASSWORDTHATCANBEUSEDHERE |
| localhost | mysql.sys | THISISNOTAVALIDPASSWORDTHATCANBEUSEDHERE |
| 192.168.1.% | backup | 9BB58B7F11A03B83C396FF506F3DF45727E79614 |
+--------------+---------------+-------------------------------------------+
5 rows in set (0.00 sec)

mysql>br/>[email protected].%账户已建立；
4、Master锁表，往slave拷贝数据

重启MySQL服务并设置读取锁定，读取锁定的意思是只能读取，不能更新，以便获得一个一致性的快照；

mysql> flush table with read lock; # 主库锁表；默认28800秒，即8小时自动解锁；
mysql> show master status;
1. row
File: mysql-bin.000002
Position: 154
Binlog_Do_DB:
Binlog_Ignore_DB: mysql
Executed_Gtid_Set: 3f46a487-5984-11e8-8edd-00163e000d73:1-8
1 row in set (0.00 sec)

mysql>
查看主服务器上当前的二进制日志名和偏移量值这里的file 和position 要和从上的一致；
导出master(192.168.1.101)上的数据，然后导入slave 中
master：
[root@MySQL-001 ~]# mysqldump -uroot -p employees > /opt/employees.sql # 假如employees为主库已经存在的库
[root@MySQL-001 ~]# yum install openssh-clients -y #(注：slave也需要安装)

slave：
[root@MySQL-001 ~]# yum install openssh-clients -y
[root@MySQL-001 ~]# scp /opt/employees.sql [email protected]:/opt/
[email protected]'s password: #输入密码
employees.bak 100%
5、配置slave(192.168.1.102)
[root@MySQL-002 ~]# vim /etc/my.cnf
[mysqld]
basedir=/usr/local/mysql # mysql路径
datadir=/data/mysqldata # mysql数据目录
socket=/tmp/mysql.sock
user=mysql
port=3306

slave配置

server_id=2 # MySQLid 后面2个从服务器需设置不同
skip_slave_start=1 # 复制进程不会随着数据库的启动而启动,需手动启动；
#加上以下参数可以避免更新不及时，SLAVE 重启后导致的主从复制出错。
read_only = 1
master_info_repository=TABLE
relay_log_info_repository=TABLE
#relay_log_recovery=1 # 从机禁止写
#super_read_only=1 # 从机禁止写
然后导入到mysql数据库中，slave上的employees数据库不存在则先创建，然后再导入
[root@MySQL-002 ~]# mysql -uroot -p
mysql> create database employees; # 新建这个库
[root@MySQL-002 ~]# mysql -uroot -p employees < /opt/employees.sql
重启数据库
CentOS 6.：
[root@MySQL-002 ~]# service mysqld restart
[root@MySQL-002 ~]# service mysqld status
SUCCESS! MySQL running (15604)
CentOS 7.：
[root@MySQL-002 ~]# systemctl restart mysqld.service
[root@MySQL-002 ~]# systemctl status mysqld.service
mysqld.service - MySQL Server
Loaded: loaded (/usr/lib/systemd/system/mysqld.service; enabled)
Active: active (running) since 四 2018-05-17 11:42:02 CST; 2h 5min ago
Docs: man:mysqld(8)
http://dev.mysql.com/doc/refman/en/using-systemd.html
Main PID: 29959 (mysqld)
CGroup: /system.slice/mysqld.service
└─29959 /opt/mysql/bin/mysqld --defaults-file=/etc/my.cnf

5月 17 11:42:02 tcloud-118 systemd[1]: Started MySQL Server.

登录slave数据库，并做如下设置
[root@MySQL-002 ~]# mysql -uroot -p
mysql> stop slave;
mysql> change master to
-> master_host='192.168.1.101', # master的ip
-> master_user='backup', # 备份用户名
-> master_password='123456', # 密码
-> master_log_file='mysql-bin.000002', # 上面截图，且要与master的参数一致
-> master_log_pos=154; # 上面截图，且要与master的参数一致
合写为：
mysql> change master to master_host='192.168.1.101', master_user='backup', master_password='123456', master_log_file='mysql-bin.000002', master_log_pos=154;
mysql> start slave;
mysql> show slave status \G # 查看slave从机的状态
1. row
Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.1.101
Master_User: backup
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.000002
Read_Master_Log_Pos: 154
Relay_Log_File: relay-bin.000002
Relay_Log_Pos: 921
Relay_Master_Log_File: mysql-bin.000002
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
Replicate_Do_DB:
Replicate_Ignore_DB: mysql
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: 1756
Relay_Log_Space: 1122
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: 118
Master_UUID: 3f46a487-5984-11e8-8edd-00163e000d73
Master_Info_File: mysql.slave_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: 3f46a487-5984-11e8-8edd-00163e000d73:6-8
Executed_Gtid_Set: 3f46a487-5984-11e8-8edd-00163e000d73:6-8
Auto_Position: 0
Replicate_Rewrite_DB:
Channel_Name:
Master_TLS_Version:
1 row in set (0.00 sec)

root@tcloud-119 15:11: [(none)]>
下面对应参数相同代表设置成功，0延时；
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
Seconds_Behind_Master: 0

6、关闭掉主数据库的读取锁定,并测试

mysql> unlock tables;
在marster中创建一个新表再查看slave中是否有数据

master:
mysql> use employees;
mysql> create table test001(id int auto_increment primary key,name varchar(20) not null);
mysql> insert into test001 values(null,'will');
mysql> insert into test001 values(null,'jim');
mysql> insert into test001 values(null,'tom');

slave:
mysql> use employees;
mysql> show tables;
有图
mysql> select * from test001;
测试2：重启关闭从数据库，主删除test001表，然后主从数据库都重启看是否正常
mysql> drop table test001;
以上实验证明主从同步成功！！！