主从复制2——拥有海量数据主服务器的主从复制模型详细实现；

基本策略：

此时需要在主服务器上先完全备份，还原到从服务器；接着开启主从复制；如果直接使用主从复制，那么主从服务器的压力很大；

主服务器数据全备份操作：

[root@master ~]$mysqldump -A -F --single-transaction --master-data=1 > all.sql

主服务器模拟修改操作：

MariaDB [(none)]> create database wangdb1;Query OK, 1 row affected (0.01 sec)MariaDB [(none)]> show master logs;+--------------------+-----------+| Log_name           | File_size |+--------------------+-----------+| mariadb-bin.000001 |      8217 || mariadb-bin.000002 |       555 || mariadb-bin.000003 |       334 |+--------------------+-----------+3 rows in set (0.00 sec)[root@master ~]$less all.sqlCHANGE MASTER TO MASTER_LOG_FILE='mariadb-bin.000003', MASTER_LOG_POS=245;

主服务器配置：

[root@slave ~]$vim /etc/my.cnf[mysqld]datadir=/var/lib/mysqlsocket=/var/lib/mysql/mysql.sock# Disabling symbolic-links is recommended to prevent assorted security riskssymbolic-links=0# Settings user and group are ignored when systemd is used.innodb_file_per_tableserver_id=2

从服务器数据还原：

[root@master ~]$scp all.sql 192.168.27.17:~[root@slave ~]$mysql < all.sql

从服务器开启主从复制：

MariaDB [(none)]> CHANGE MASTER TO    -> MASTER_HOST='192.168.27.7',    -> MASTER_USER='repluser',    -> MASTER_PASSWORD='centos',    -> MASTER_LOG_FILE='mariadb-bin.000003',    -> MASTER_LOG_POS=245;Query OK, 0 rows affected (0.01 sec)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: 192.168.27.7                  Master_User: repluser                  Master_Port: 3306                Connect_Retry: 60              Master_Log_File: mariadb-bin.000003          Read_Master_Log_Pos: 334               Relay_Log_File: mariadb-relay-bin.000002                Relay_Log_Pos: 620        Relay_Master_Log_File: mariadb-bin.000003             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: 334              Relay_Log_Space: 916              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: 11 row in set (0.00 sec)

从服务器数据一致性保证：

由于从服务器上的数据也是可以被删除的，所以为了保证数据的一致性，可以将只读属性打开；这种情况下，MySQL的root用户依然是可以修改删除的，只是对于普通用户生效；    MariaDB [(none)]> show variables like 'read_only';    +---------------+-------+    | Variable_name | Value |    +---------------+-------+    | read_only     | OFF   |    +---------------+-------+    1 row in set (0.00 sec)[root@slave ~]$vim /etc/my.cnf[mysqld]datadir=/var/lib/mysqlsocket=/var/lib/mysql/mysql.sock# Disabling symbolic-links is recommended to prevent assorted security riskssymbolic-links=0# Settings user and group are ignored when systemd is used.innodb_file_per_tableserver_id=2read_onlyMariaDB [(none)]> grant select,update,delete on *.* to test@'192.168.27.%' identified by 'centos';Query OK, 0 rows affected (0.00 sec)[root@master ~]$mysql -utest -pcentos -h292.168.27.17MariaDB [hellodb]> select * from students where age='22';+-------+---------------+-----+--------+---------+-----------+| StuID | Name          | Age | Gender | ClassID | TeacherID |+-------+---------------+-----+--------+---------+-----------+|     1 | Shi Zhongyu   |  22 | M      |       2 |         3 ||     2 | Shi Potian    |  22 | M      |       1 |         7 ||    21 | Huang Yueying |  22 | F      |       6 |      NULL |+-------+---------------+-----+--------+---------+-----------+3 rows in set (0.00 sec)MariaDB [hellodb]> delete from students;ERROR 1290 (HY000): The MariaDB server is running with the --read-only option so it cannot execute this statement