Docker搭建 MySQL 主从复制

为什么选 Docker

搭建主从复制需要两个以上的MySQL， 使用 Docker 非常方便。如果以前没用过，找个简单的文档看看，熟悉一下命令。

搭建过程

1.下载镜像

docker pull mysql:5.7.

2.创建服务器

docker run --name mysql_master -p : -e MYSQL_ROOT_PASSWORD= -d mysql:5.7.
 
//通过镜像 mysql:5.7.21 启动一个名为 mysql_master 的 MySQL 服务器，端口号是3306，映射的宿主机端口号是3310，root 账号密码是123456

3.创建Slave服务器

docker run --name mysql_slave  -p : -e MYSQL_ROOT_PASSWORD= -d mysql:5.7.

通过 docker container ls -a  可以看到创建成功

CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                    NAMES
d2298154e6d4        mysql:5.7.        "docker-entrypoint.s…"    hours ago         Up  hours          0.0.0.0:->/tcp   mysql_slave
b8d7e74b2d31        mysql:5.7.        "docker-entrypoint.s…"    hours ago         Up About an hour    0.0.0.0:->/tcp   mysql_master

4.查看IP

docker inspect --format='{{.NetworkSettings.IPAddress}}' b8d
//172.17.0.2
docker inspect --format='{{.NetworkSettings.IPAddress}}' d22
//172.17.0.3

master IP : 172.17.0.2

slave   IP : 172.17.0.3

MySQL 配置

1. Master 配置

//进入Master服务器
docker exec -it b8d /bin/bash
//进的入配置
cd /etc/mysql
//修改配置文件--my.cnf增加下面两行
server_id=
log-bin=mysql-bin
//配置完成后重启
service mysql restart
//如果容器停止了，要从新启动进入，docker container start b8d
//再次进入容器
mysql -uroot -p
//执行下面命令进行复制授权
CREATE USER 'slave'@'%' IDENTIFIED BY '';
GRANT REPLICATION SLAVE, REPLICATION CLIENT ON *.* TO 'slave'@'%';
//检查命令
show master status;
 
+------------------+----------+--------------+------------------+-------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+-------------------+
| mysql-bin. |     370 |              |                  |                   |
+------------------+----------+--------------+------------------+-------------------+
 row in set (0.00 sec)
 
//File Position 两个数据后面配置 Slave 会用到。

2. Slave 配置

//进入Slave 容器
docker exec -it d22  /bin/bash
//配置mysql，增加下面
server_id=
log-bin=mysql-bin
//重启进入执行
change master to master_host='172.17.0.2', master_user='slave', master_password='', master_port=, master_log_file='mysql-bin.000002', master_log_pos=, master_connect_retry=;
//启动
start slave;
//查看主从同步状态
show slave status \G;
 
*************************** . row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 172.17.0.2
                  Master_User: slave
                  Master_Port:
                Connect_Retry:
              Master_Log_File: mysql-bin.
          Read_Master_Log_Pos:
               Relay_Log_File: d2298154e6d4-relay-bin.
                Relay_Log_Pos:
        Relay_Master_Log_File: mysql-bin.
             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:
                   Last_Error:
                 Skip_Counter:
          Exec_Master_Log_Pos:
              Relay_Log_Space:
              Until_Condition: None
               Until_Log_File:
                Until_Log_Pos:
           Master_SSL_Allowed: No
           Master_SSL_CA_File:
           Master_SSL_CA_Path:
              Master_SSL_Cert:
            Master_SSL_Cipher:
               Master_SSL_Key:
        Seconds_Behind_Master:
Master_SSL_Verify_Server_Cert: No
                Last_IO_Errno:
                Last_IO_Error:
               Last_SQL_Errno:
               Last_SQL_Error:
  Replicate_Ignore_Server_Ids:
             Master_Server_Id:
                  Master_UUID: 2cf67843--11e8-bfa5-0242ac110002
             Master_Info_File: /var/lib/mysql/master.info
                    SQL_Delay:
          SQL_Remaining_Delay: NULL
      Slave_SQL_Running_State: Slave has read all relay log; waiting for more updates
           Master_Retry_Count:
                  Master_Bind:
      Last_IO_Error_Timestamp:
     Last_SQL_Error_Timestamp:
               Master_SSL_Crl:
           Master_SSL_Crlpath:
           Retrieved_Gtid_Set:
            Executed_Gtid_Set:
                Auto_Position:
         Replicate_Rewrite_DB:
                 Channel_Name:
           Master_TLS_Version:
 row in set (0.00 sec)

Slave_IO_Running: Yes 和 Slave_SQL_Running: Yes  表明配置成功。 配置 master_log_file='mysql-bin.000002',  master_log_pos=370, 这两个参数要注意 和 show

master status 输出的值保持一致，不然会出现同步错误。