mysql主从复制原理

环境：

3306 主库

3307 从库

1 设置server-id值并开启binlog功能参数

编辑mysql的配置文件/data/3306/my.cnf

[mysqld]

server-id = 6              ----用于同步的每台机器或实例sever-id都不能相同

log_bin =/data/3306/mysql-bin  ----可以省略

重启服务

/data/3306/mysql restart

检查思路一

[root@db02 data]# egrep "log_bin|server-id" 330*/my.cnf

3306/my.cnf:log_bin = /data/3306/mysql-bin

3306/my.cnf:server-id = 6

3307/my.cnf:server-id = 7

检查思路二：

检查思路2：

登录：

[root@db02 data]# mysql -S /data/3306/mysql.sock 

查看变量：

mysql> show variables like 'log_bin%';

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

| Variable_name                   | Value                      |

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

| log_bin                         | ON                         |

| log_bin_basename                | /data/3306/mysql-bin       |

| log_bin_index                   | /data/3306/mysql-bin.index |

| log_bin_trust_function_creators | OFF                        |

| log_bin_use_v1_row_events       | OFF                        |

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

5 rows in set (0.00 sec)

2 建账号授权【主库】

grant replication slave on *.* to 'rep'@'172.16.1.%' identified by 'oldboy123';

flush privileges;

3锁表导出数据

mysql> flush table with read lock;

Query OK, 0 rows affected (0.00 sec)

查看位置：

mysql> show master status;

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

| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |

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

| mysql-bin.000001 |      405 |              |                  |                   |

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

1 row in set (0.00 sec)

新开窗口备份：

mysqldump -uroot -p'oldboy123' -S /data/3306/mysql.sock -A -B |gzip >/server/backup/mysql_bak.$(date +%F).sql.gz

原窗口解锁：

mysql> show master status;

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

| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |

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

| mysql-bin.000001 |      405 |              |                  |                   |

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

1 row in set (0.00 sec)

mysql> unlock tables;

Query OK, 0 rows affected (0.01 sec)

如下命令可替代3的所有步骤

mysqldump -uroot -p'oldboy123' --master-data=2 -S /data/3306/mysql.sock -A -B

4、将数据导入到从库

[root@db02 backup]# mysql -S /data/3307/mysql.sock <mysql_bak.2017-05-04.sql

5、让从库从主库锁表时刻记录的binlog位置点开始向下同步

CHANGE MASTER TO  

MASTER_HOST='172.16.1.52', 

MASTER_PORT=3306,

MASTER_USER='rep', 

MASTER_PASSWORD='oldboy123', 

MASTER_LOG_FILE='mysql-bin.000001',

MASTER_LOG_POS=405;