什么是多源复制
在我们以前的数据库主从复制和高可用的配置中，如果一旦高可用服务器切换，从机不能复制新启动的backup主机，原因是因为 slave机器没有同步master2机器，而只是同步了master1机器。
master1 从master2 同步了数据，只是写入master自己的中继日志，而没有写入自己的binlog日志，这样slave机器就不能读取master1的binlog日志。
解决这个问题的方法，就是在版本高于10的mariadb或者mysql5.7当中，做多远复制，就是slave机器同时同步二台master机器
环境
| 机器IP | 角色 |
| 192.168.137.4 | master1 |
| 192.168.137.5 | master2 |
| 192.168.137.6 | slave1 |
| 服务器 centos7.9 mariadb 10.3.14 |
配置步骤
- 配置数据源，
cat <<EOF >/etc/yum.repos.d/mariadb.repo
[mariadb]
name = MariaDB
baseurl = http://yum.mariadb.org/10.3/centos7-amd64
gpgkey=https://yum.mariadb.org/RPM-GPG-KEY-MariaDB
gpgcheck=1
EOF- 更新缓存，注意，10.0以后，安装的包名变成了大写的MariaDB
# yum clean all
# yum list |grep MariaDB-server
MariaDB-rocksdb-engine.x86_64 10.3.28-1.el7.centos mariadb
MariaDB-rocksdb-engine-debuginfo.x86_64 10.3.28-1.el7.centos mariadb
MariaDB-server.x86_64 10.3.28-1.el7.centos mariadb
MariaDB-server-debuginfo.x86_64 10.3.28-1.el7.centos mariadb
MariaDB-shared.x86_64 10.3.28-1.el7.centos mariad- 安装
-
[root@localhost ~]# yum list --showduplicates MariaDB-server 已加载插件：fastestmirror Loading mirror speeds from cached hostfile * base: mirrors.aliyun.com * extras: mirrors.163.com * updates: mirrors.aliyun.com 已安装的软件包 MariaDB-server.x86_64 10.3.28-1.el7.centos @mariadb 可安装的软件包 MariaDB-server.x86_64 10.3.26-1.el7.centos mariadb MariaDB-server.x86_64 10.3.27-1.el7.centos mariadb MariaDB-server.x86_64 10.3.28-1.el7.centos mariadb mariadb-server.x86_64 1:5.5.68-1.el7 [root@localhost ~]# yum install MariaDB-server 已加载插件：fastestmirror Loading mirror speeds from cached hostfile * base: mirrors.aliyun.com * extras: mirrors.163.com * updates: mirrors.aliyun.com 正在解决依赖关系 --> 正在检查事务 ---> 软件包 MariaDB-server.x86_64.0.10.3.28-1.el7.centos 将被 安装 --> 正在处理依赖关系 perl(Data::Dumper)，它被软件包 MariaDB-server-10.3.28-1.el 7.centos.x86_64 需要 ==== perl-Time-HiRes.x86_64 4:1.9725-3.el7 perl-Time-Local.noarch 0:1.2300-2.el7 perl-constant.noarch 0:1.27-2.el7 perl-libs.x86_64 4:5.16.3-299.el7_9 perl-macros.x86_64 4:5.16.3-299.el7_9 perl-parent.noarch 1:0.225-244.el7 perl-podlators.noarch 0:2.5.1-3.el7 perl-threads.x86_64 0:1.87-4.el7 perl-threads-shared.x86_64 0:1.43-6.el7 rsync.x86_64 0:3.1.2-10.el7 替代: mariadb-libs.x86_64 1:5.5.68-1.el7 - 启动服务
-
[root@localhost ~]# systemctl restart mariadb [root@localhost ~]# netstat -antp Active Internet connections (servers and established) Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN 1061/sshd tcp 0 0 127.0.0.1:25 0.0.0.0:* LISTEN 1327/master tcp 0 0 192.168.137.5:22 192.168.137.2:62865 ESTABLISHED 1573/sshd: root@not tcp 0 0 192.168.137.5:22 192.168.137.2:62863 ESTABLISHED 1569/sshd: root@pts tcp6 0 0 :::3306 :::* LISTEN 2087/mysqld tcp6 0 0 :::22 :::* LISTEN 1061/sshd tcp6 0 0 ::1:25 :::* LISTEN 1327/master [root@localhost ~]# mysql Welcome to the MariaDB monitor. Commands end with ; or \g. Your MariaDB connection id is 8 Server version: 10.3.28-MariaDB MariaDB Server Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. MariaDB [(none)]> exit Bye [root@localhost ~]#配置主主复制
- 二台主主机器上增加一个用户
[root@localhost my.cnf.d]# mysql
Welcome to the MariaDB monitor. Commands end with ; or \g.
Your MariaDB connection id is 16
Server version: 10.3.28-MariaDB-log MariaDB Server
Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
MariaDB [(none)]> grant replication slave on *.* to mm_slave@'%' identified by '123456';
MariaDB [(none)]> flush privileges;
修改主主二台机器的配置，关闭防火墙，重启。
[mariadb-10.3]
server_id=1 #不能重复，137.4使用1 ，137.5使用 2
log-bin
auto_increment_offset=1 137.4使用1 ，137.5使用 2
auto_increment_increment=2
加入复制
-- 注意，二个机器都要增加，确定master_host是对方的机器
MariaDB [(none)]> change master to master_host='192.168.137.5' , master_password='123456';
Query OK, 0 rows affected (0.024 sec)
MariaDB [(none)]> start slave;
Query OK, 0 rows affected (0.002 sec)
测试通过
MariaDB [(none)]> show slave status \G
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.137.5
Master_User: mm_slave
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: localhost-bin.000001
Read_Master_Log_Pos: 653
Relay_Log_File: localhost-relay-bin.000002
Relay_Log_Pos: 956
Relay_Master_Log_File: localhost-bin.000001
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
从服务器加入二个主
增加server_id,重启启动
-- /etc/my.cnf
[mariadb]
server_id=3
加入主，记得所有的mater别名必须加单引号。否则会报错。
ERROR 1200 (HY000): Misconfigured slave: MASTER_HOST was not set; Fix in config file or with CHANGE MASTER TO
正确加入如下
MariaDB [(none)]> change master 'master1374' to master_host='192.168.137.4', master_password='123456',master_user='mm_slave';
MariaDB [(none)]> start slave 'master1374'
MariaDB [(none)]> change master 'master1375' to master_host='192.168.137.4', master_password='123456',master_user='mm_slave';
MariaDB [(none)]> start slave 'master1375'MariaDB [(none)]> show slave 'master1374' status\G
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.137.4
Master_User: mm_slave
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: localhost-bin.000001
Read_Master_Log_Pos: 653
Relay_Log_File: localhost-relay-bin-master1374.000002
Relay_Log_Pos: 956
Relay_Master_Log_File: localhost-bin.000001
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
MariaDB [(none)]> show slave 'master1375' status\G
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.137.5
Master_User: mm_slave
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: localhost-bin.000001
Read_Master_Log_Pos: 653
Relay_Log_File: localhost-relay-bin-master1374.000002
Relay_Log_Pos: 956
Relay_Master_Log_File: localhost-bin.000001
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
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