1. 环境

Red Hat Enterprise Linux Server release 7.0 (Maipo)（虚拟机）
mysql5.7 下载链接

2. 安装和配置主从复制

解压

tar xzvf mysql-5.7.23-linux-glibc2.12-x86_64.tar.gz -C /export/server
cd /export/server
mv mysql-5.7.23-linux-glibc2.12-x86_64 mysql

添加mysql目录的所属组和所属者：

groupadd mysql
useradd -r -g mysql mysql
cd /export/server
chown -R mysql:mysql mysql/
chmod -R 755 mysql/

创建mysql数据存放目录（其中/export/data是我创建专门用来为各种服务存放数据的目录）
```
mkdir /export/data/mysql
```
初始化mysql服务

cd /export/server/mysql
./bin/mysqld --basedir=/export/server/mysql --datadir=/export/data/mysql --user=mysql --pid-file=/export/data/mysql/mysql.pid --initialize

# 如果成功会显示mysql的root账户的初始密码，记下来以备后续登录。如果报错缺少依赖，则使用yum instally依次安装即可

配置my.cnf

vim /etc/my.cnf

[mysqld]
basedir=/export/server/mysql
datadir=/export/data/mysql
socket=/tmp/mysql.sock
user=mysql
server-id=10 # 服务id，在集群时必须唯一，建议设置为IP的第四段
port=3306
# Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links=0
# Settings user and group are ignored when systemd is used.
# If you need to run mysqld under a different user or group,
# customize your systemd unit file for mariadb according to the
# instructions in http://fedoraproject.org/wiki/Systemd

[mysqld_safe]
log-error=/export/data/mysql/error.log
pid-file=/export/data/mysql/mysql.pid

#
# include all files from the config directory
#
!includedir /etc/my.cnf.d

将服务添加到开机自动启动

cp /export/server/mysql/support-files/mysql.server /etc/init.d/mysqld

启动服务
```
service mysqld start
```

配置环境变量，在/etc/profile中添加如下内容

# mysql env
MYSQL_HOME=/export/server/mysql
MYSQL_PATH=$MYSQL_HOME/bin
PATH=$PATH:$MYSQL_PATH
export PATH

使配置即可生效
```
source /etc/profile
```

使用root登录

mysql -uroot -p
# 这里填写之前初始化服务时提供的密码

登录上去之后，更改root账户密码（我为了方便将密码改为root），否则操作数据库会报错
```
set password=password('root');
flush privileges;
```

设置服务可被所有远程客户端访问

use mysql;
update user set host='%' where user='root';
flush privileges;

3. 配置主从节点

3.1. 配置master

以linux（192.168.10.10）上的mysql为master，宿主机（192.168.10.1）上的mysql为slave配置主从复制。

修改master的my.cnf如下

[mysqld]
basedir=/export/server/mysql
datadir=/export/data/mysql
socket=/tmp/mysql.sock
user=mysql
server-id=10
port=3306
# Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links=0
# Settings user and group are ignored when systemd is used.
# If you need to run mysqld under a different user or group,
# customize your systemd unit file for mariadb according to the
# instructions in http://fedoraproject.org/wiki/Systemd

log-bin=mysql-bin    # 开启二进制日志
expire-logs-days=7  # 设置日志过期时间，避免占满磁盘
binlog-ignore-db=mysql    # 不使用主从复制的数据库
binlog-ignore-db=information_schema
binlog-ignore-db=performation_schema
binlog-ignore-db=sys
binlog-do-db=test    #使用主从复制的数据库

[mysqld_safe]
log-error=/export/data/mysql/error.log
pid-file=/export/data/mysql/mysql.pid

#
# include all files from the config directory
#
!includedir /etc/my.cnf.d

重启master
```
service mysqld restart
```
登录master查看配置是否生效（ON即为开启，默认为OFF）

mysql> show variables like 'log_bin';
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| log_bin       | ON    |
+---------------+-------+

在master的数据库中建立备份账号：backup为用户名，%表示任何远程地址，用户back可以使用密码1234通过任何远程客户端连接master
```
grant replication slave on *.* to 'backup'@'%' identified by '1234'
```

查看user表可以看到我们刚创建的用户：

mysql> use mysql
mysql> select user,authentication_string,host from user;
+---------------+-------------------------------------------+-----------+
| user          | authentication_string                     | host      |
+---------------+-------------------------------------------+-----------+
| root          | *81F5E21E35407D884A6CD4A731AEBFB6AF209E1B | %         |
| mysql.session | *THISISNOTAVALIDPASSWORDTHATCANBEUSEDHERE | localhost |
| mysql.sys     | *THISISNOTAVALIDPASSWORDTHATCANBEUSEDHERE | localhost |
| backup        | *A4B6157319038724E3560894F7F932C8886EBFCF | %         |
+---------------+-------------------------------------------+-----------+

新建test数据库，创建一个article表以备后续测试

CREATE TABLE `article` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`title` varchar(64) DEFAULT NULL,
`content` text,
PRIMARY KEY (`id`)
) CHARSET=utf8;

重启服务并刷新数据库状态到存储文件中（with read lock表示在此过程中，客户端只能读数据，以便获得一个一致性的快照）

[root@zhenganwen ~]# service mysqld restart
Shutting down MySQL.... SUCCESS!
Starting MySQL. SUCCESS!
[root@zhenganwen mysql]# mysql -uroot -proot
mysql> flush tables with read lock;
Query OK, 0 rows affected (0.00 sec)

查看master上当前的二进制日志和偏移量（记一下其中的File和Position）

mysql> show master status \G
*************************** 1. row ***************************
           File: mysql-bin.000002
       Position: 154
   Binlog_Do_DB: test
Binlog_Ignore_DB: mysql,information_schema,performation_schema,sys
Executed_Gtid_Set:
1 row in set (0.00 sec)

File表示实现复制功能的日志，即上图中的Binary log；Position则表示Binary log日志文件的偏移量之后的都会同步到slave中，那么在偏移量之前的则需要我们手动导入。主服务器上面的任何修改都会保存在二进制日志Binary log里面，从服务器上面启动一个I/O thread（实际上就是一个主服务器的客户端进程），连接到主服务器上面请求读取二进制日志，然后把读取到的二进制日志写到本地的一个Realy log里面。从服务器上面开启一个SQL thread定时检查Realy log，如果发现有更改立即把更改的内容在本机上面执行一遍。如果一主多从的话，这时主库既要负责写又要负责为几个从库提供二进制日志。此时可以稍做调整，将二进制日志只给某一从，这一从再开启二进制日志并将自己的二进制日志再发给其它从。或者是干脆这个从不记录只负责将二进制日志转发给其它从，这样架构起来性能可能要好得多，而且数据之间的延时应该也稍微要好一些

手动导入，从master中导出数据

mysqldump -uroot -proot -hlocalhost test > /export/data/test.sql
将test.sql中的内容在slave上执行一遍

3.2. 配置slave

修改slave的my.ini文件中的[mysqld]部分
```
log-bin=mysql
server-id=1 #192.168.10.1
```
保存修改后重启slave，WIN+R->services.msc->MySQL5.7->重新启动
登录slave检查log_bin是否以被开启

show VARIABLES like 'log_bin';

配置与master的同步复制

stop slave;
change master to
    master_host='192.168.10.10',    -- master的IP
    master_user='backup',            -- 之前在master上创建的用户
    master_password='1234',
    master_log_file='mysql-bin.000002', -- master上 show master status \G 提供的信息
    master_log_pos=154;

启用slave节点并查看状态

mysql> start slave;
mysql> show slave status \G
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 192.168.10.10
                  Master_User: backup
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000002
          Read_Master_Log_Pos: 154
               Relay_Log_File: DESKTOP-KUBSPE0-relay-bin.000002
                Relay_Log_Pos: 320
        Relay_Master_Log_File: mysql-bin.000002
             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: 0
                   Last_Error:
                 Skip_Counter: 0
          Exec_Master_Log_Pos: 154
              Relay_Log_Space: 537
              Until_Condition: None
               Until_Log_File:
                Until_Log_Pos: 0
           Master_SSL_Allowed: No
           Master_SSL_CA_File:
           Master_SSL_CA_Path:
              Master_SSL_Cert:
            Master_SSL_Cipher:
               Master_SSL_Key:
        Seconds_Behind_Master: 0
Master_SSL_Verify_Server_Cert: No
                Last_IO_Errno: 0
                Last_IO_Error:
               Last_SQL_Errno: 0
               Last_SQL_Error:
  Replicate_Ignore_Server_Ids:
             Master_Server_Id: 10
                  Master_UUID: f68774b7-0b28-11e9-a925-000c290abe05
             Master_Info_File: C:\ProgramData\MySQL\MySQL Server 5.7\Data\master.info
                    SQL_Delay: 0
          SQL_Remaining_Delay: NULL
      Slave_SQL_Running_State: Slave has read all relay log; waiting for more updates
           Master_Retry_Count: 86400
                  Master_Bind:
      Last_IO_Error_Timestamp:
     Last_SQL_Error_Timestamp:
               Master_SSL_Crl:
           Master_SSL_Crlpath:
           Retrieved_Gtid_Set:
            Executed_Gtid_Set:
                Auto_Position: 0
         Replicate_Rewrite_DB:
                 Channel_Name:
           Master_TLS_Version:
1 row in set (0.00 sec)
*** 注意查看第4、14、15三行，若与我一致，表示slave配置成功 ***

3.3. 测试

关闭master的读取锁定

mysql> unlock tables;
Query OK, 0 rows affected (0.00 sec)

向master中插入一条数据

mysql> use test
mysql> insert into article (title,content) values ('mysql master and slave','record the cluster building succeed!:)');
Query OK, 1 row affected (0.00 sec)

查看slave是否自动同步了数据

mysql> insert into article (title,content) values ('mysql master and slave','record the cluster building succeed!:)');
Query OK, 1 row affected (0.00 sec)

作者：公众号_程序员乔戈里链接：https://juejin.im/post/5c2c53396fb9a04a053fc7fe 来源：掘金著作权归作者所有。商业转载请联系作者获得授权，非商业转载请注明出处。

主从配置