搭建Mysql主从复制

Posted 2021-04-23 java王文龙

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目录

01：linux中安装docker

02：使用docker安装mysql

03：可视化工具连接mysql

04：主机中分配用户

05：开启binlog

06：配置从机

07：创建数据库，测试主从复制

01

linux中安装docker

---

首先说明一点，我在linux中安装docker是为了更好的安装其他应用程序，如mysql、nginx，简单方便，当然小伙伴儿们也可以手动一步步安装应用程序，linux中安装docker命令如下：

[root@localhost mysql]# yum -y install docker

查看版本，出现下面内容说明安装成功

[root@localhost mysql]# docker -vDocker version 1.13.1, build 0be3e21/1.13.1

启动docker

[root@localhost mysql]# service docker start

02

使用docker安装mysql

本次通过docker在linux中安装两个mysql，一个做主机，另一个做从机，通过后面的配置达到主从复制的效果

• 安装第一个mysql

[root@localhost /]# docker run --name mysql1 -p 33061:3306 -e MYSQL_ROOT_PASSWORD=root1234 -d mysql:5.7 --character-set-server=utf8mb4 --collation-server=utf8mb4_unicode_ci

--name ：表示创建的容器的名字

-d ：表示容器在后台运行

-p ： 表示将容器的 3306端口映射到宿主机的 33061 端口

MYSQL_ROOT_PASSWORD ：设置密码

--character-set-server ： 设置数据库字符集

--collation-server ：排序规则

mysql：5.7 指定安装mysql的版本，本次就以安装5.7版本为例

docker run 命令：容器创建+启动的命令，如果不想启动，可以用docker create 命令创建所需容器，即使创建不启动，后面还需手动再启动一遍，所以我这里直接用了 docker run 命令一步操作

• 安装第二个mysql

跟上面操作一致，只要端口号和名称不一致即可，其他看小伙伴们自己意愿可自行修改

[root@localhost /]# docker run --name mysql2 -p 33062:3306 -e MYSQL_ROOT_PASSWORD=root1234 -d mysql:5.7 --character-set-server=utf8mb4 --collation-server=utf8mb4_unicode_ci

03

可视化工具连接mysql

我的两个mysql都装在了同一个Linux系统中，所以两个mysql的主机地址是一样的，唯一不一样的是端口号

                                                                                                                         

04

主机分配用户

上面我创建了两个mysql，一个是mysql1，另一个是mysql2，那么我就把mysql1作为主机，mysql2作为从机，首先给主机重新分配一个用户，目的是为从机登录主机读取数据用的，操作如下：

---

Navicat中输入命令：

GRANT REPLICATION SLAVE ON *.* TO 'repl'@'%' IDENTIFIED BY 'root1234';

*.* ： 表示任意库中的任意表

repl ： 用户的名字，小伙伴儿们可以起其他名字，这里用repl为例

% ： 表示可以用任意位置登录，当然也可以写固定的ip地址

IDENTIFIED BY ： 设置登录密码

效果如下：

点击用户可看到刚分配的用户效果如下：

05

开启binlog

注：只有开启了binlog之后，从机才能读取都主机中数据的变化

• 进入 mysql1容器

[root@localhost /]# docker exec -it mysql1 /bin/bash

我docker中没有装vi编辑器（当然如果不嫌麻烦的话，也可以装一个，不过我觉得没什么必要），所以我从docker退出去后，新建一个同名的文件，把配置复制到新创建的文件，修改完配置后再放到docker中覆盖即可，要想开启binlog就得修改配置文件。

• 查看原配置：

root@125dfce1b700:/# cat /etc/mysql/mysql.conf.d/mysqld.cnf

• 配置如下：

# Copyright (c) 2014, 2016, Oracle and/or its affiliates. All rights reserved.## This program is free software; you can redistribute it and/or modify# it under the terms of the GNU General Public License, version 2.0,# as published by the Free Software Foundation.## This program is also distributed with certain software (including# but not limited to OpenSSL) that is licensed under separate terms,# as designated in a particular file or component or in included license# documentation. The authors of MySQL hereby grant you an additional# permission to link the program and your derivative works with the# separately licensed software that they have included with MySQL.## This program is distributed in the hope that it will be useful,# but WITHOUT ANY WARRANTY; without even the implied warranty of# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the# GNU General Public License, version 2.0, for more details.## You should have received a copy of the GNU General Public License# along with this program; if not, write to the Free Software# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
## The MySQL Server configuration file.## For explanations see# http://dev.mysql.com/doc/mysql/en/server-system-variables.html
[mysqld]pid-file = /var/run/mysqld/mysqld.pidsocket = /var/run/mysqld/mysqld.sockdatadir = /var/lib/mysql#log-error = /var/log/mysql/error.log# By default we only accept connections from localhost#bind-address = 127.0.0.1# Disabling symbolic-links is recommended to prevent assorted security riskssymbolic-links=0

• 退出容器

[root@localhost /]# exit

在自己操作系统中创建同名文件，修改后的配置如下：

[root@localhost /]# vi mysqld.cnf

注：名字一定不要错

opyright (c) 2014, 2016, Oracle and/or its affiliates. All rights reserved.## This program is free software; you can redistribute it and/or modify# it under the terms of the GNU General Public License, version 2.0,# as published by the Free Software Foundation.## This program is also distributed with certain software (including# but not limited to OpenSSL) that is licensed under separate terms,# as designated in a particular file or component or in included license# documentation. The authors of MySQL hereby grant you an additional# permission to link the program and your derivative works with the# separately licensed software that they have included with MySQL.## This program is distributed in the hope that it will be useful,# but WITHOUT ANY WARRANTY; without even the implied warranty of# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the# GNU General Public License, version 2.0, for more details.## You should have received a copy of the GNU General Public License# along with this program; if not, write to the Free Software# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA

## The MySQL Server configuration file.## For explanations see# http://dev.mysql.com/doc/mysql/en/server-system-variables.html[mysqld]
log-bin=/var/lib/mysql/binlogserver-id=1binlog-do-db=master_slave_database

pid-file = /var/run/mysqld/mysqld.pidsocket = /var/run/mysqld/mysqld.sockdatadir = /var/lib/mysql#log-error = /var/log/mysql/error.log# By default we only accept connections from localhost#bind-address = 127.0.0.1# Disabling symbolic-links is recommended to prevent assorted security riskssymbolic-links=0

注： 主要添加了三行配置，上面的配置文件第31~33行

log-bin：binlog的位置，这个位置要确保有操作权限

server-id: 给主机设置id

binlog-do-db:设置哪些库可以被复制

• 通过docker命令将修改好的配置拷贝到下面的文件夹中

[root@localhost /]# docker cp ./mysqld.cnf mysql1:/etc/mysql/mysql.conf.d/

• 重启mysql1

[root@localhost /]# docker restart mysql1

• 主机中创建数据库master_slave_database（主机中配置的是哪个数据库就建哪个数据库）

• 可视化工具（Navicat）输入命令出现下面效果说明开启binlog成功
  

show master status;

注：file、position、binlog_do_db的内容记住，待会配置从机的时候要用到

• 配置从机mysql2 

步骤跟配mysql1的步骤是一样的，新建文件，修改配置，然后覆盖原文件即可，从机只是配置内容变了（只配一个server-id=2即可），配置如下

[mysqld]server-id=2
pid-file = /var/run/mysqld/mysqld.pidsocket = /var/run/mysqld/mysqld.sockdatadir = /var/lib/mysql#log-error = /var/log/mysql/error.log# By default we only accept connections from localhost#bind-address = 127.0.0.1# Disabling symbolic-links is recommended to prevent assorted security riskssymbolic-links=0

• 重启mysql2
  

[root@localhost /]# docker restart mysql2

06

配置从机

• 进入mysql2容器

[root@localhost /]# docker exec -it mysql2 /bin/bash

• 登录

root@490fac23b15d:/# mysql -u root -p Enter password: 输入自己设置的mysql密码，然后回车即可，会出现下面内容Welcome to the MySQL monitor. Commands end with ; or \g.Your MySQL connection id is 2Server version: 5.7.33 MySQL Community Server (GPL)
Copyright (c) 2000, 2021, Oracle and/or its affiliates.
Oracle is a registered trademark of Oracle Corporation and/or itsaffiliates. Other names may be trademarks of their respectiveowners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql>

• 开启数据同步【就是指定从机的master是谁】

mysql> change master to master_host='10.20.60.130',master_port=33061,master_user='rep1',master_password='root1234',master_log_file='binlog.000002',master_log_pos=735;
//返回这条数据，说明成功了：Query OK, 0 rows affected, 2 warnings (0.03 sec)

• 查看状态

mysql> show slave status\G;

上面两行都是yes才算成功，如果不成功请查看报错信息，如上图

 Last_IO_Error: error connecting to master 'rep1@10.20.60.130:33061' - retry-time: 60 retries: 969

• 停止从机

mysql> stop slave

• linux打开新窗口【重点：打开新窗口】，查看主机的docker的ip。这样当前页面就不用重复退出mysql及docker容器再重新进入了

[root@localhost /]# docker inspect mysql1

回车后拉到最下面，IPADDress就是docker容器的ip

• 回到刚才的页面重新开启数据同步

mysql> change master to master_host='172.17.0.1',master_port=3306,master_user='rep1',master_password='root1234',master_log_file='binlog.000002',master_log_pos=735;

• 启动从机，并且查看状态
  

mysql> start slave;Query OK, 0 rows affected (0.01 sec)
mysql> show slave status\G;

此时可以看到，Slave_IO_Running: Yes，Slave_SQL_Running: Yes，说明已经成功了

07

创建数据库，测试主从复制

从机中创建 master_slave_database 数据库（跟主机保持一致），创建成功后在主机的master_slave_database 库中创建一个user表，刷新从机，此时会看到从机中master_slave_database 库里也出现了user表，说明主从复制配置成功，效果如下

主机中添加一条数据，看是否能从从机中查询到（观察下面两图的mysql连接是不一样的）

能查到结果，说明配置成功了，至此结束，关注下方公众号获取更多内容！