三台主机实现级联复制

需要在中间的从服务器启用以下配置 ，实现中间slave节点能将master的二进制日志在本机进行数据库更新，并且也同时更新本机的二进制，从而实现级联复制。

 #在Master实现

[root@centos8 ~]#vim /etc/my.cnf.d/mariadb-server.cnf

[mysqld]
server-id=8
log-bin

[root@centos8 ~]#systemctl restart mariadb
[root@centos8 ~]#mysql
MariaDB [(none)]> grant replication slave on *.* to repluser@'10.0.0.%' identified by 'magedu';
[root@centos8 ~]#mysqldump -A -F --single-transaction --master-data=1 > /data/all.sql
[root@centos8 ~]#scp /data/all.sql 10.0.0.18:/data
[root@centos8 ~]#scp /data/all.sql 10.0.0.28:/data

#在中间级联slave实现

[root@centos8 ~]#vim /etc/my.cnf.d/mariadb-server.cnf

[mysqld]
server-id=18
log-bin
read-only
log_slave_updates #级联复制中间节点的必选项,MySQL8.0此为默认值,可以不要人为添加
[root@centos8 ~]#systemctl restart mariadb

 还原数据库

[root@centos8 ~]#vim /data/all.sql

CHANGE MASTER TO
MASTER_HOST='master节点的iP',
MASTER_USER='repluser',
MASTER_PASSWORD='centos',
MASTER_PORT=3306,
MASTER_LOG_FILE='mysql-bin.000004',
MASTER_LOG_POS=523;

[root@centos8 ~]#mysql
MariaDB [(none)]> set sql_log_bin=0;
MariaDB [(none)]> source /data/all.sql
MariaDB [(none)]> show master logs; #记录二进制位置，给第三个节点使用
MariaDB [(none)]> set sql_log_bin=0;
MariaDB [(none)]> start slave;

#在第三个节点slave上实现
 

[root@centos8 ~]#vim /etc/my.cnf.d/mariadb-server.cnf

[mysqld]
server-id=28
read-only

[root@centos8 ~]#systemctl restart mariadb
[root@centos8 ~]#vim /data/all.sql

CHANGE MASTER TO
MASTER_HOST='中间节点的IP',
MASTER_USER='repluser',
MASTER_PASSWORD='magedu',
MASTER_PORT=3306,
MASTER_LOG_FILE='mariadb-bin.000002', MASTER_LOG_POS=344;

[root@centos8 ~]#mysql < /data/all.sql
[root@centos8 ~]#mysql -e 'start slave;'