Docker搭建MySQL主从复制

Docker搭建MySQL主从复制

1. 主从服务器上分别安装Docker

   1.1 Docker 要求 CentOS 系统的内核版本高于 3.10

   [root@localhost ~]# uname -r
   3.10.0-693.el7.x86_64
   

   1.2 确保 yum 包更新到最新。

   [root@localhost ~]# sudo yum update
   Loaded plugins: fastestmirror, langpacks
   Loading mirror speeds from cached hostfile
    * base: mirrors.cqu.edu.cn
    * extras: mirrors.cqu.edu.cn
    * updates: mirrors.cqu.edu.cn
   base                                                                                                                                             | 3.6 kB  00:00:00
   docker-ce-stable                                                                                                                                 | 3.5 kB  00:00:00
   extras                                                                                                                                           | 2.9 kB  00:00:00
   updates                                                                                                                                          | 2.9 kB  00:00:00
   

   1.3 安装需要的软件包， yum-util 提供yum-config-manager功能，另外两个是devicemapper驱动依赖的

   [root@localhost ~]# sudo yum install -y yum-utils device-mapper-persistent-data lvm2
   Loaded plugins: fastestmirror, langpacks
   Loading mirror speeds from cached hostfile
    * base: mirrors.cqu.edu.cn
    * extras: mirrors.cqu.edu.cn
    * updates: mirrors.cqu.edu.cn
   Package yum-utils-1.1.31-52.el7.noarch already installed and latest version
   Package device-mapper-persistent-data-0.8.5-1.el7.x86_64 already installed and latest version
   Package 7:lvm2-2.02.185-2.el7_7.2.x86_64 already installed and latest version
   Nothing to do
   

   1.4 设置yum源

   [root@localhost ~]# sudo yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo
   Loaded plugins: fastestmirror, langpacks
   adding repo from: https://download.docker.com/linux/centos/docker-ce.repo
   grabbing file https://download.docker.com/linux/centos/docker-ce.repo to /etc/yum.repos.d/docker-ce.repo
   repo saved to /etc/yum.repos.d/docker-ce.repo
   

   1.5 安装docker

   [root@localhost ~]#  sudo yum install docker-ce
   Loaded plugins: fastestmirror, langpacks
   Loading mirror speeds from cached hostfile
    * base: mirrors.cqu.edu.cn
    * extras: mirrors.cqu.edu.cn
    * updates: mirrors.cqu.edu.cn
   Package 3:docker-ce-19.03.8-3.el7.x86_64 already installed and latest version
   Nothing to do
   

   1.6 启动docker并设置docker自动启动

   [root@localhost ~]# sudo systemctl start docker
   [root@localhost ~]# sudo systemctl enable docker
   

   1.7 检测docker是否安装成功

   [root@localhost ~]# docker version
   Client: Docker Engine - Community
    Version:           19.03.8
    API version:       1.40
    Go version:        go1.12.17
    Git commit:        afacb8b
    Built:             Wed Mar 11 01:27:04 2020
    OS/Arch:           linux/amd64
    Experimental:      false
   
   Server: Docker Engine - Community
    Engine:
     Version:          19.03.8
     API version:      1.40 (minimum version 1.12)
     Go version:       go1.12.17
     Git commit:       afacb8b
     Built:            Wed Mar 11 01:25:42 2020
     OS/Arch:          linux/amd64
     Experimental:     false
    containerd:
     Version:          1.2.13
     GitCommit:        7ad184331fa3e55e52b890ea95e65ba581ae3429
    runc:
     Version:          1.0.0-rc10
     GitCommit:        dc9208a3303feef5b3839f4323d9beb36df0a9dd
    docker-init:
     Version:          0.18.0
     GitCommit:        fec3683
   
   

2. docker更换国内阿里仓库，并下载安装MySQL

   2.1 docker更换国内阿里仓库

   sudo mkdir -p /etc/docker
   sudo tee /etc/docker/daemon.json <<-'EOF'
   {
     "registry-mirrors": ["https://rdwyjupq.mirror.aliyuncs.com"]
   }
   EOF
   sudo systemctl daemon-reload
   sudo systemctl restart docker
   

   2.2 安装MySQL

   ​ 2.2.1 下载MySQL

   [root@localhost ~]# docker pull mysql
   Using default tag: latest
   latest: Pulling from library/mysql
   c499e6d256d6: Pull complete
   22c4cdf4ea75: Pull complete
   6ff5091a5a30: Pull complete
   2fd3d1af9403: Pull complete
   0d9d26127d1d: Pull complete
   54a67d4e7579: Pull complete
   fe989230d866: Pull complete
   3a808704d40c: Pull complete
   826517d07519: Pull complete
   69cd125db928: Pull complete
   b5c43b8c2879: Pull complete
   1811572b5ea5: Pull complete
   Digest: sha256:b69d0b62d02ee1eba8c7aeb32eba1bb678b6cfa4ccfb211a5d7931c7755dc4a8
   Status: Downloaded newer image for mysql:latest
   docker.io/library/mysql:latest
   

   ​ 2.2.2 查看MySQL镜像

   [root@localhost ~]# docker images
   REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
   mysql               latest              9228ee8bac7a        4 days ago          547MB
   

   ​ 2.2.3 创建MySQL的挂载文件目录（日志、数据、配置）

   [root@localhost ~]# mkdir -p /root/mysql/data /root/mysql/logs /root/mysql/conf
   

   ​ 2.2.4 先启动容器（为了复制配置文件）（这种做法显得多余，但是Docker不是很精通的我没想到更好的办法，请各位大神指导）

   [root@localhost conf]# docker run -d -p 3306:3306 --name mysql -e MYSQL_ROOT_PASSWORD="123456" mysql
   05d161e69f3b2e3e4ebaa50f822934599a31e7ade330e1440a68aec9e404f7ae
   

   ​ 2.2.5 复制配置文件

   [root@localhost conf]# docker cp mysql:/etc/mysql/my.cnf /root/mysql/conf/
   

   ​ 2.2.6 停止并删容器

   [root@localhost conf]# docker stop mysql
   mysql
   [root@localhost conf]# docker rm mysql
   mysql
   

   ​ 2.2.7 重新启动容器（加上挂载）

   [root@localhost conf]# docker run --name mysql -p 3306:3306 -e MYSQL_ROOT_PASSWORD=123456 --mount type=bind,src=/root/mysql/conf/my.cnf,dst=/etc/mysql/my.cnf --mount ty
   pe=bind,src=/root/mysql/data,dst=/var/lib/mysql --mount type=bind,src=/root/mysql/logs,dst=/logs --restart=on-failure:3 -d mysql64824c7e84ceb3513b65a375c55f2c53bc653f95b119008296122b13ff632ba1
   

   ​ 2.2.8 进入MySQL查询现有字符集，结果都是utf8mb4

   show variables like '%char%';
   

   ​ 2.2.9 在挂载的配置文件更改字符集

   character-set-server=utf8
   
   default-character-set=utf8
   
   default-character-set=utf8
   

   ​ 2.2.10 重启docker容器，并查看字符集已经更改，证明挂载的配置文件有效

1. 搭建主从复制数据库

   3.1 配置主Master库

   ​ 3.1.1 进入主库挂载配置文件my.cnf，加入以下配置并重启docker容器

   [mysqld]
   ## 同一局域网内注意要唯一
   server-id=100
   ## 开启二进制日志功能，可以随便取（关键）
   log-bin=mysql-bin
   

   ​ 3.1.2 在主Master库执行语句

   CREATE USER 'slave'@'%' IDENTIFIED BY '123456';
   GRANT REPLICATION SLAVE, REPLICATION CLIENT ON *.* TO 'slave'@'%';
   

   ​ 为防止后面出现报错[Authentication plugin 'caching_sha2_password' cannot be loaded]，执行下面语句

   ALTER USER 'slave'@'%' IDENTIFIED BY 'password' PASSWORD EXPIRE NEVER;   #修改加密规则
   ALTER USER 'slave'@'%' IDENTIFIED WITH mysql_native_password BY 'password';   #更新一下用户的密码
   FLUSH PRIVILEGES;
   alter user 'slave'@'%' identified by '123456';
   

   最后执行语句获取File， Position

   show master status;
   

   3.2 配置从Slave库

   ​ 3.2.1 进入从库挂载配置文件my.cnf，加入以下配置并重启docker容器

   [mysqld]
   ## 设置server_id,注意要唯一
   server-id=101
   ## 开启二进制日志功能，以备Slave作为其它Slave的Master时使用
   log-bin=mysql-slave-bin
   ## relay_log配置中继日志
   relay_log=edu-mysql-relay-bin
   

   ​ 3.2.2 链接主从库，在从库执行语句

   change master to master_host='192.168.47.128', master_user='slave', master_password='123456', master_port=3306, master_log_file='mysql-bin.000001', master_log_pos= 5938, master_connect_retry=30;
   

   master_host ：Master的地址

   master_port：Master的端口号，指的是容器的端口号

   master_user：用于数据同步的用户

   master_password：用于同步的用户的密码

   master_log_file：指定 Slave 从哪个日志文件开始复制数据，即上文中提到的 File 字段的值

   master_log_pos：从哪个 Position 开始读，即上文中提到的 Position 字段的值

   master_connect_retry：如果连接失败，重试的时间间隔，单位是秒，默认是60秒

   ​ 3.2.3 查看主从同步状态

   show slave status ;
   

​ 正常情况下，SlaveIORunning 和 SlaveSQLRunning 都是No，因为我们还没有开启主从复制过程。

  3.2.4 开启主从复制

start slave;

重新查看主从同步状态， 这时SlaveIORunning 和 SlaveSQLRunning 都是Yes，如果你的SlaveIORunning 和 SlaveSQLRunning 其中一个是Connecting或者No，就证明配置有错，查看Last_IO_Error报错的详细信息

通过下面命令，删除已经配置的主从链接信息，重新进行配置

stop slave;
reset master;

	 3.2.5 测试主从复制，最简单的方式是在主库建立个新库，这时，从库会自动同步