MySQL数据库读写分离（小白的“升级打怪”成长之路）

数据库角色	IP	应用与系统版本
master	192.168.166.25	rocky linux9.4 mysql-8.0.36
slave	192.168.166.26	rocky linux9.4 mysql-8.0.36
slave2	192.168.166.27	rocky linux9.4 mysql-8.0.36
maxscale	192.168.166.9	rocky linux9.4 maxscale24.02.3-GA

2、mysql主从复制配置

分别在主从三台服务器上安装mysql8，并配置主从复制。

##由于认证插件问题，需要在master服务器使用下述命令进行更改密码的验证插件。
ALTER USER'slave'@'%' IDENTIFIED WITH mysql_native_password BY 'password';
FLUSH PRIVILEGES;

###修改认证插件
##my.cnf
default-authentication-plugin=mysql_native_password

3、maxscale安装

#下载yum源
[root@maxscale ~]# curl -LsS https://r.mariadb.com/downloads/mariadb_repo_setup | sudo bash

# [info] Checking for script prerequisites.

# [info] MariaDB Server version 11.2 is valid

# [info] Repository file successfully written to /etc/yum.repos.d/mariadb.repo

# [info] Adding trusted package signing keys...

/etc/pki/rpm-gpg ~
~

# [info] Successfully added trusted package signing keys

# [info] Cleaning package cache...

25 files removed
[root@maxscale ~]# ls /etc/yum.repos.d/
mariadb.repo  rocky-addons.repo  rocky-devel.repo  rocky-extras.repo  rocky.repo
#安装maxscale
[root@maxscale ~]# yum -y install maxscale

4、配置maxscale

登录到主库

[root@master ~]# mysql -uroot
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 14
Server version: 8.0.36 MySQL Community Server - GPL

Copyright (c) 2000, 2023, Oracle and/or its affiliates.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
#创建maxscale用户密码是maxscale
mysql> CREATE USER 'maxscale'@'%' IDENTIFIED BY 'maxscale';
Query OK, 0 rows affected (0.00 sec)
#授权maxscale可以查询所有数据库
mysql> GRANT SELECT ON mysql.* TO 'maxscale'@'%';
Query OK, 0 rows affected (0.01 sec)
#授权可以看所有数据库
mysql> GRANT SHOW DATABASES ON *.* TO 'maxscale'@'%';
Query OK, 0 rows affected (0.00 sec)
#创建admin用户可以在maxscale上登录
mysql> CREATE USER 'admin'@'192.168.166.%' IDENTIFIED BY 'admin';
Query OK, 0 rows affected (0.01 sec)

在maxscale上安装mysql

[root@maxscale ~]# yum -y install mysql
[root@maxscale ~]# which mysql
/usr/bin/mysql
#登录到master
[root@maxscale ~]# mysql -uadmin -padmin -h192.168.166.25
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 15
Server version: 8.0.36 MySQL Community Server - GPL

Copyright (c) 2000, 2023, Oracle and/or its affiliates.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
####因为没有权限所以只能看到两个数据库
mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| performance_schema |
+--------------------+
2 rows in set (0.00 sec)

mysql> exit
Bye

回到master主库设置增删改查权限

mysql> GRANT CREATE, SELECT, INSERT, UPDATE, DELETE ON *.* TO 'admin'@'192.168.166.%';
Query OK, 0 rows affected (0.00 sec)

在maxscale上修改配置文件

[root@maxscale ~]# vim /etc/maxscale.cnf
#先看有无这个
[maxscale]
threads=auto

#修改后端服务器地址
[server1]
type=server
address=192.168.166.25
port=3306
protocol=MySQLBackend

[server2]
type=server
address=192.168.166.26
port=3306
protocol=MySQLBackend

[server3]
type=server
address=192.168.166.27
port=3306
protocol=MySQLBackend

#配置监控
[MySQL-Monitor]
type=monitor
module=mariadbmon
servers=server1,server2,server3
user=monitor
password=monitor
monitor_interval=2s

#注释掉只读配置
#[Read-Only-Service]
#type=service
#router=readconnroute
#servers=server2
#user=maxscale
#password=maxscale
#router_options=slave

#修改读写分离服务
[Read-Write-Service]
type=service
router=readwritesplit
servers=server1,server2,server3
user=maxscale
password=maxscale
version_string = 8.0
#配置listener
#注释掉只读
#[Read-Only-Listener]
#type=listener
#service=Read-Only-Service
#protocol=mariadbprotocol
#port=4008
#修改读写分离
[Read-Write-Listener]
type=listener
service=Read-Write-Service
protocol=mariadbprotocol
port=3306 #(伪装成数据库端口3306)

切换到主库创建monitor用户

mysql> CREATE USER 'monitor'@'%' IDENTIFIED BY 'monitor';
Query OK, 0 rows affected (0.01 sec)
#再添加授权
mysql> GRANT REPLICATION CLIENT on *.* to 'monitor'@'%';
Query OK, 0 rows affected (0.00 sec)

mysql> GRANT REPLICATION SLAVE on *.* to 'monitor'@'%';
Query OK, 0 rows affected (0.01 sec)

mysql> GRANT SUPER,RELOAD on *.* to 'monitor'@'%';
Query OK, 0 rows affected, 1 warning (0.01 sec)

启动服务

[root@maxscale ~]# systemctl start maxscale

查看端口

[root@maxscale ~]# ss -antl
State     Recv-Q    Send-Q       Local Address:Port       Peer Address:Port   Process    
LISTEN    0         4096             127.0.0.1:8989            0.0.0.0:*                 
LISTEN    0         128                0.0.0.0:22              0.0.0.0:*                 
LISTEN    0         4096                     *:3306                  *:*                 
LISTEN    0         128                   [::]:22                 [::]:*                 
[root@maxscale ~]# ss -antlp
State      Recv-Q     Send-Q          Local Address:Port           Peer Address:Port     Process                                                                                  
LISTEN     0          4096                127.0.0.1:8989                0.0.0.0:*         users:(("maxscale",pid=15450,fd=19))                                                    
LISTEN     0          128                   0.0.0.0:22                  0.0.0.0:*         users:(("sshd",pid=792,fd=3))                                                           
LISTEN     0          4096                        *:3306                      *:*         users:(("maxscale",pid=15450,fd=27))                                                    
LISTEN     0          128                      [::]:22                     [::]:*         users:(("sshd",pid=792,fd=4))

查看有哪些服务

[root@maxscale ~]# maxctrl list services
┌────────────────────┬────────────────┬─────────────┬───────────────────┬───────────────────────────┐
│ Service            │ Router         │ Connections │ Total Connections │ Targets                   │
├────────────────────┼────────────────┼─────────────┼───────────────────┼───────────────────────────┤
│ Read-Write-Service │ readwritesplit │ 0           │ 0                 │ server1, server2, server3 │
└────────────────────┴────────────────┴─────────────┴───────────────────┴───────────────────────────┘

查看后台服务器有哪些

[root@maxscale ~]# maxctrl list servers
┌─────────┬─────────────────┬──────┬─────────────┬─────────────────┬──────┬───────────────┐
│ Server  │ Address         │ Port │ Connections │ State           │ GTID │ Monitor       │
├─────────┼─────────────────┼──────┼─────────────┼─────────────────┼──────┼───────────────┤
│ server1 │ 192.168.166.25 │ 3306 │ 0           │ Master, Running │      │ MySQL-Monitor │
├─────────┼─────────────────┼──────┼─────────────┼─────────────────┼──────┼───────────────┤
│ server2 │ 192.168.166.27 │ 3306 │ 0           │ Slave, Running  │      │ MySQL-Monitor │
├─────────┼─────────────────┼──────┼─────────────┼─────────────────┼──────┼───────────────┤
│ server3 │ 192.168.166.26 │ 3306 │ 0           │ Slave, Running  │      │ MySQL-Monitor │
└─────────┴─────────────────┴──────┴─────────────┴─────────────────┴──────┴───────────────┘

测试

用客户机连接maxscale

username：admin
password：admin

会发现进行读操作时，是在slave的从数据库上执行；在进行写操作时，是在master主数据库上执行

实战案例

1、配置mysql数据库主从复制

两台设备(ip分别为192.168.58.160和192.168.58.161)都安装mysql服务

[root@mysql-slave ~]# yum install -y mysql-server
[root@mysql-slave ~]# systemctl start mysqld

主服务配置

对时

#192.168.58.160
[root@localhost ~]# timedatectl set-timezone Asia/Shanghai
[root@mysql ~]# vim /etc/chrony.conf
# Use public servers from the pool.ntp.org project.
# Please consider joining the pool (http://www.pool.ntp.org/join.html).
pool 2.rocky.pool.ntp.org iburst

# Record the rate at which the system clock gains/losses time.
driftfile /var/lib/chrony/drift

##添加修改此字段
# Use public servers from the pool.ntp.org project.
# Please consider joining the pool (http://www.pool.ntp.org/join.html).
#pool 2.rocky.pool.ntp.org iburst
server ntp.aliyun.com iburst
# Record the rate at which the system clock gains/losses time.
driftfile /var/lib/chrony/drift


[root@mysql ~]# systemctl restart chronyd.service 
[root@mysql ~]# hostnamectl set-hostname mysql-master
[root@mysql ~]# bash

[root@mysql-master ~]# mysql
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 76
Server version: 8.0.41 Source distribution

Copyright (c) 2000, 2025, Oracle and/or its affiliates.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> create user slave@'192.168.58.%' identified by '123.com';    #创建从主机可以进行访问的用户slave
Query OK, 0 rows affected (0.02 sec)

mysql> grant all on *.* to slave@'192.168.58.%';    #给slave用户赋权
Query OK, 0 rows affected (0.02 sec)

mysql> exit
Bye
[root@mysql-master ~]# vim /etc/my.cnf.d/mysql-server.cnf 
[mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
log-error=/var/log/mysql/mysqld.log
pid-file=/run/mysqld/mysqld.pid

#添加命令，启用二进制日志记录功能
[mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
log-error=/var/log/mysql/mysqld.log
pid-file=/run/mysqld/mysqld.pid
log-bin=mysql-bin
binlog_format="statement"

[root@mysql-master ~]# systemctl restart mysqld
#关闭防火墙和SELinux
[root@mysql-master ~]# systemctl stop firewalld
[root@mysql-master ~]# setenforce 0
[root@mysql-master ~]# cd /var/lib/mysql
#验证配置
[root@mysql-master mysql]# ls
 auto.cnf          db1                  mysql-bin.000001     private_key.pem
 binlog.000001    '#ib_16384_0.dblwr'   mysql-bin.index      public_key.pem
 binlog.000002    '#ib_16384_1.dblwr'   mysql.ibd            server-cert.pem
 binlog.000003     ib_buffer_pool       mysql.sock           server-key.pem
 binlog.index      ibdata1              mysql.sock.lock      sys
 ca-key.pem        ibtmp1               mysql_upgrade_info   test
 ca.pem           '#innodb_redo'        mysqlx.sock          test2
 client-cert.pem  '#innodb_temp'        mysqlx.sock.lock     undo_001
 client-key.pem    mysql                performance_schema   undo_002

[root@mysql-master mysql]# mysql
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 9
Server version: 8.0.41 Source distribution

Copyright (c) 2000, 2025, Oracle and/or its affiliates.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

#查看master正在使用的日志文件及日志书写位置
mysql> show master status;
+------------------+----------+--------------+------------------+-------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+-------------------+
| mysql-bin.000001 |      157 |              |                  |                   |
+------------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)
#注意：查看位置完毕后，不要对master做任何操作，等配置完从服务再进行其余操作

从服务器配置

对时

#192.168.58.161
[root@localhost ~]# timedatectl set-timezone Asia/Shanghai
[root@mysql ~]# vim /etc/chrony.conf
# Use public servers from the pool.ntp.org project.
# Please consider joining the pool (http://www.pool.ntp.org/join.html).
pool 2.rocky.pool.ntp.org iburst

# Record the rate at which the system clock gains/losses time.
driftfile /var/lib/chrony/drift

##添加修改此字段
# Use public servers from the pool.ntp.org project.
# Please consider joining the pool (http://www.pool.ntp.org/join.html).
#pool 2.rocky.pool.ntp.org iburst
server ntp.aliyun.com iburst
# Record the rate at which the system clock gains/losses time.
driftfile /var/lib/chrony/drift

[root@mysql ~]# systemctl restart chronyd.service 
[root@localhost ~]# hostnamectl set-hostname mysql-slave
[root@localhost ~]# bash
[root@mysql-slave ~]# vim /etc/my.cnf.d/mysql-server.cnf 
[mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
log-error=/var/log/mysql/mysqld.log
pid-file=/run/mysqld/mysqld.pid

#添加命令，启用二进制日志中继日志
[mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
log-error=/var/log/mysql/mysqld.log
pid-file=/run/mysqld/mysqld.pid
binlog_format="statement"
relay-log-index=slave-bin.index
server-id=22

[root@mysql-slave ~]# systemctl restart mysqld
#关闭防火墙和SELinux
[root@mysql-slave ~]# systemctl stop firewalld
[root@mysql-slave ~]# setenforce 0
[root@mysql-slave ~]# cd /var/lib/mysql
#配置验证，此时没有与主服务器进行连接，所以没有产生对应的relay log
[root@mysql-slave mysql]# ls
 auto.cnf         '#ib_16384_0.dblwr'   mysql.ibd            public_key.pem
 binlog.000001    '#ib_16384_1.dblwr'   mysql.sock           server-cert.pem
 binlog.000002     ib_buffer_pool       mysql.sock.lock      server-key.pem
 binlog.index      ibdata1              mysql_upgrade_info   sys
 ca-key.pem        ibtmp1               mysqlx.sock          undo_001
 ca.pem           '#innodb_redo'        mysqlx.sock.lock     undo_002
 client-cert.pem  '#innodb_temp'        performance_schema
 client-key.pem    mysql                private_key.pem
[root@mysql-slave mysql]# mysql
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 8
Server version: 8.0.41 Source distribution

Copyright (c) 2000, 2025, Oracle and/or its affiliates.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

##配置从服务器的所属主服务器
mysql> change master to master_host='192.168.58.160',master_user='slave',master_password='123.com',master_log_file='mysql-bin.000001',master_log_pos=157;
Query OK, 0 rows affected, 8 warnings (0.02 sec)

##启动slave角色，默认没有配置主从时，所有的mysql节点都是master
mysql> start slave;
Query OK, 0 rows affected, 2 warnings (0.01 sec)

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| sys                |
+--------------------+
4 rows in set (0.01 sec)

验证结果

#192.168.58.160
#创建新库c2505
mysql> create database c2505;
Query OK, 1 row affected (0.00 sec)

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| c2505              |
| information_schema |
| mysql              |
| performance_schema |
| sys                |
+--------------------+
8 rows in set (0.01 sec)

#192.168.58.161
#验证，查看到这里也创建了一个新库c2505
mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| c2505              |
| information_schema |
| mysql              |
| performance_schema |
| sys                |
+--------------------+
5 rows in set (0.00 sec)

2、配置maxscale

#192.168.58.170
[root@bogon ~]# hostnamectl set-hostname maxscale
[root@bogon ~]# bash
#安装maxscale
[root@maxscale ~]# yum -y install maxscale
[root@maxscale ~]# yum -y install mariadb

修改主从服务器数据库配置文件

#192.168.58.160
#登录到主库
root@mysql-master mysql]# vim /etc/my.cnf.d/mysql-server.cnf 
[mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
log-error=/var/log/mysql/mysqld.log
pid-file=/run/mysqld/mysqld.pid
log-bin=mysql-bin
binlog_format="statement"

[mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
log-error=/var/log/mysql/mysqld.log
pid-file=/run/mysqld/mysqld.pid
log-bin=mysql-bin
binlog_format="statement"
server-id=11    #添加此id，注意此id不能与其他服务器id相同
default-authentication-plugin=mysql_native_password     #修改认证插件

[root@mysql-master mysql]# systemctl restart mysqld
[root@mysql-master mysql]# mysql 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 10
Server version: 8.0.41 Source distribution

Copyright (c) 2000, 2025, Oracle and/or its affiliates.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

#创建maxscale用户密码是maxscale
mysql> create user maxscale@'%' identified by 'maxscale';
Query OK, 0 rows affected (0.02 sec)
#授权maxscale用户
mysql> grant all on *.* to maxscale@'%';
Query OK, 0 rows affected (0.01 sec)
#创建admin用户可以在maxscale上登录
mysql> create user 'admin'@'192.168.58.%' identified by 'admin';
Query OK, 0 rows affected (0.01 sec)
mysql> grant create,select,insert,update,delete on *.* to 'admin'@'192.168.58.%';
Query OK, 0 rows affected (0.00 sec)

创建monitor用户
mysql> create user 'monitor'@'%' identified by 'monitor';
Query OK, 0 rows affected (0.01 sec)

mysql> grant replication client on *.* to 'monitor'@'%';
Query OK, 0 rows affected (0.00 sec)

mysql> grant replication slave on *.* to 'monitor'@'%';
Query OK, 0 rows affected (0.01 sec)

mysql> grant super,reload on *.* to 'monitor'@'%';
Query OK, 0 rows affected, 1 warning (0.00 sec)

#192.168.58.161
[root@mysql-slave mysql]# vim /etc/my.cnf.d/mysql-server.cnf
mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
log-error=/var/log/mysql/mysqld.log
pid-file=/run/mysqld/mysqld.pid
binlog_format="statement"
relay-log-index=slave-bin.index

[mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
log-error=/var/log/mysql/mysqld.log
pid-file=/run/mysqld/mysqld.pid
binlog_format="statement"
relay-log-index=slave-bin.index
server-id=22    #添加此id，注意此id不能与其他服务器id相同
default-authentication-plugin=mysql_native_password     #修改认证插件

[root@mysql-slave mysql]# systemctl restart mysqld

更改maxscale的配置文件

#192.168.58.170
[root@maxscale ~]# mysql -uadmin -padmin -h192.168.58.160
Welcome to the MariaDB monitor.  Commands end with ; or \g.
Your MySQL connection id is 12
Server version: 8.0.41 Source distribution

Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

MySQL [(none)]> show databases;
+--------------------+
| Database           |
+--------------------+
| c2505              |
| db1                |
| information_schema |
| mysql              |
| performance_schema |
| sys                |
| test               |
| test2              |
+--------------------+
8 rows in set (0.009 sec)
 
MySQL [(none)]> exit
Bye

[root@maxscale ~]# vim /etc/maxscale.cnf

[maxscale]
threads=auto

[server1]
type=server
address=192.168.58.160
port=3306
protocol=MySQLBackend

[server2]
type=server
address=192.168.58.161
port=3306
protocol=MySQLBackend


[MySQL-Monitor]
type=monitor
module=mariadbmon
servers=server1,server2
user=monitor
password=monitor
monitor_interval=2s

#注释掉只读配置
#[Read-Only-Service]
#type=service
#router=readconnroute
#servers=server2
#user=maxscale
#password=maxscale
#router_options=slave

#修改读写分离服务
[Read-Write-Service]
type=service
router=readwritesplit
servers=server1,server2
user=maxscale
password=maxscale
version_string = 8.0
#配置listener
#注释掉只读
#[Read-Only-Listener]
#type=listener
#service=Read-Only-Service
#protocol=mariadbprotocol
#port=4008
#修改读写分离
[Read-Write-Listener]
type=listener
service=Read-Write-Service
protocol=mariadbprotocol
port=3306

[root@maxscale ~]# setenforce 0
[root@maxscale ~]# systemctl stop firewalld

启动服务

#192.168.58.170
[root@maxscale ~]# systemctl start maxscale

验证结果

MySQL数据库读写分离（小白的“升级打怪”成长之路）

一、maxscale概述

MaxScale核心介绍

主要功能特性

二、读写分离

1、环境说明