转发自：https://blog.csdn.net/money9sun/article/details/85099134
第一步：安装docker https://www.cnblogs.com/cyq632694540/p/10596276.html
第二步：检查mysql的镜像，并下载
# docker search mysql:5.7
# docker pull mysql:5.7
# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
docker.io/mysql 5.7 ae6b78bedf88 4 weeks ago 372 MB
第三步：开启两个mysql的容器
建立自定义的网络，用于两个容易互相通信
# docker network create --subnet=172.18.0.0/16 mynetwork
开启master01
# docker run -p 3308:3306 -p 22002:22 --name master01 -e MYSQL_ROOT_PASSWORD=123456 --net mynetwork --ip 172.18.0.2 -d mysql:5.7
开启master02
# docker run -p 3309:3306 -p 22003:22 --name master02 -e MYSQL_ROOT_PASSWORD=123456 --net mynetwork --ip 172.18.0.3 -d mysql:5.7
第三步：安装软件及修改配置
# docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
a2e76f0faae1 mysql:5.7 "docker-entrypoint..." 26 hours ago Up 25 hours 33060/tcp, 0.0.0.0:22004->22/tcp, 0.0.0.0:3309->3306/tcp master02
1b6773fc8c3d mysql:5.7 "docker-entrypoint..." 26 hours ago Up 25 hours 33060/tcp, 0.0.0.0:22003->22/tcp, 0.0.0.0:3308->3306/tcp master01
进入master01容器
# docker exec -it 1b6773fc8c3d /bin/bash
root@1b6773fc8c3d:/# apt-get update
root@1b6773fc8c3d:/# apt-get install vim
root@1b6773fc8c3d:/# cd /etc/mysql/mysql.conf.d
root@1b6773fc8c3d:/# ls
mysqld.cnf
修改配置文件
root@1b6773fc8c3d:/# vi mysqld.cnf
添加的内容如下：
server-id=31
auto-increment-increment=2
auto-increment-offset=1
log-bin=/var/log/mysql/mysql-bin.log
binlog_format=mixed
relay-log=relay-bin
log-slave-updates
保存；
service mysql restart 这时候容器会退出，再启动即可，命令 docker restart 容器id即可
同样的方法，进入master02容器，配置文件修改为
server-id=32
auto-increment-increment=2
auto-increment-offset=2 ### 这里要注意 offset是偏移量，保证不同的mysql主机生成的主键是不同的，避免主键冲突
log-bin=/var/log/mysql/mysql-bin.log
binlog_format=mixed
relay-log=relay-bin
log-slave-updates
保存并重启mysql服务。
第四步：创建同步账户，开启slave
1、进入master01容器
# mysql -u root -p
2、创建同步账户
mysql>grant replication slave,replication client on *.* to 'slave'@'%' identified by '123456';
mysql> flush privileges;
mysql> flush tables with read lock;
3、查看binlog的状态
mysql>show master status;
+------------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+-------------------+
| mysql-bin.000001 | 433 | | | |
+------------------+----------+--------------+------------------+-------------------+
1 row in set (0.01 sec)
4、进入master02容器
# mysql -u root -p
5、创建同步账户
mysql>grant replication slave,replication client on *.* to 'slave'@'%' identified by '123456';
mysql> flush privileges;
mysql> CHANGE MASTER TO MASTER_HOST='172.18.0.2',MASTER_PORT=3308,MASTER_USER='slave',MASTER_PASSWORD='123456',MASTER_LOG_FILE='mysql-bin.000001',MASTER_LOG_POS=433;
// PS：这边的用户信息，pos，和主服务器IP要填写正确；连接错误的话，请查看 show slave status \G 里面的 【 Last_IO_Error 】和 【Last_SQL_Error】 错误信息，进行错误排查
//相关操作
stop slave;
start slave;
show slave status \G;
show master status;
mysql> start slave;
mysql> show slave status \G
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 172.18.0.2
Master_User: slave
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.000001
Read_Master_Log_Pos: 3184
Relay_Log_File: relay-bin.000002
Relay_Log_Pos: 1346
Relay_Master_Log_File: mysql-bin.000001
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
看到 Slave_IO_Running: Yes Slave_SQL_Running: Yes 表示成功
7、查看master02 binlog的状态
mysql>show master status;
+------------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+-------------------+
| mysql-bin.000001 | 521 | | | |
+------------------+----------+--------------+------------------+-------------------+
1 row in set (0.01 sec)
8、回到master01 并进入mysql控制台，创建同步账户
mysql> CHANGE MASTER TO MASTER_HOST='172.18.0.3',MASTER_PORT=3309,MASTER_USER='slave',MASTER_PASSWORD='123456',MASTER_LOG_FILE='mysql-bin.000001',MASTER_LOG_POS=521;
mysql> start slave;
mysql> show slave status \G
2019-05-30 更新------>出现主主不同步的情况时：
进入mysql
> show slave status \G; //查看错误日志
然后会有个提示 让你看下某个表下面的log
select * from performance_schema.replication_applier_status_by_worker \G ;
然后看下什么原因导致的错误；解决问题后。
设置mysql的my.cnf 配置
添加此段信息 slave-skip-errors=all 跳过错误的同步，重启mysql 搞定
