MySQL高可用——MaxScale

羡仙. • 2020 年 02 月 26 日

本文基于MHA

依赖包yum install -y novacom-server.x86_64 libaio.x86_64 libaio-devel.x86_64

安装

官网下载地址

[root@localhost softpackage]# rpm -ivh maxscale-2.4.7-1.centos.7.x86_64.rpm

警告：maxscale-2.4.7-1.centos.7.x86_64.rpm: 头V4 RSA/SHA1 Signature, 密钥 ID 28c12247: NOKEY

准备中... ################################# [100%]

正在升级/安装...

1:maxscale-2.4.7-1 ################################# [100%]

Created symlink from /etc/systemd/system/multi-user.target.wants/maxscale.service to /usr/lib/systemd/system/maxscale.service.

环境介绍服务器功能hostnameMysql Server_id192.168.128.125从库qvbilam_mha_111

192.168.128.126主库qvbilam_mha_212

192.168.128.127从库qvbilam_mha_313

192.168.128.128从库qvbilam_mha_414

192.168.128.129MHA,MaxScalelocalhost-

使用

创建权限用户-- 创建监控账号

create user qvbilam_scale_monitor@'192.168.128.%' identified by 'qvbilam';

-- 授权用于监控服务账号权限

grant replication slave,replication client on *.* to qvbilam_scale_monitor@'192.168.128.%';

-- 创建路由账号

create user qvbilam_scale_route@'192.168.128.%' identified by 'qvbilam';

-- 授予路由账号权限

grant select on mysql.* to qvbilam_scale_route@'192.168.128.%';

修改配置# cp /etc/maxscale.cnf /etc/maxscale.cnf.back

vi /etc/maxscale.cnf

# --------------- 内容如下 ---------------

# 进程数,

[maxscale]

threads=auto

# 数据库地址

[server1]

type=server

address=192.168.128.125

port=3306

protocol=MariaDBBackend

[server2]

type=server

address=192.168.128.126

port=3306

protocol=MariaDBBackend

[server3]

type=server

address=192.168.128.127

port=3306

protocol=MariaDBBackend

[server4]

type=server

address=192.168.128.128

port=3306

protocol=MariaDBBackend

# 监控模块

[MariaDB-Monitor]

type=monitor

module=mariadbmon

servers=server1,server2,server3,server4 # 需要监控的服务器

user=qvbilam_scale_monitor # Mysql监控用户

password=qvbilam # Mysql监控密码

monitor_interval=2000 # 监控间隔时间/毫秒

# 只读模块,不需要注释掉

# [Read-Only-Service]

# type=service

# router=readconnroute

# servers=server1

# user=myuser

# password=mypwd

# router_options=slave

# 读写分离模块

[Read-Write-Service]

type=service

router=readwritesplit

servers=server1,server2,server3,server4 # 服务列表

user=qvbilam_scale_route # mysql创建的路由账号

password=qvbilam # mysql路由账号的密码

max_slave_replication_lag=60 # 从服务器延迟超过60秒后不参与读写分离的集群中

# 只读服务监听,不需要注释掉

# [Read-Only-Listener]

# type=listener

# service=Read-Only-Service

# protocol=MariaDBClient

# port=4008

# 读写分离监听

[Read-Write-Listener]

type=listener

service=Read-Write-Service

protocol=MariaDBClient

port=3006 # 默认4006,为了方便相当于使用mysql.

# maxadmin 服务

[MaxAdmin-Service]

type=service

router=cli

[MaxAdmin-Listener]

type=listener

service=MaxAdmin-Service

protocol=maxscaled

port=6603

启动# 惊奇的发现会自动生成maxscale 用户

[root@localhost ~]# cat /etc/passwd | grep maxscale

maxscale:x:995:994::/home/maxscale:/bin/false

# 启动报错

[root@localhost ~]# maxscale

Error: MaxScale cannot be run as root.

Failed to write child process message!

# 不让用root启动,用自动创建的用户启动测试

[root@localhost ~]# maxscale --u=maxscale

Failed to open file '/var/log/maxscale/maxscale.log': 13, Permission denied

# 给log文件权限后再启动

[root@localhost ~]# chmod 777 maxscale.log

[root@localhost maxscale]# maxscale --u=maxscale -f /etc/maxscale.cnf

# 通过maxadmin查看集群状态 默认账号admin,默认密码mariadb

[root@localhost ~]# maxadmin --user=admin --password=mariadb

MaxScale> list servers

Servers.

-------------------+-----------------+-------+-------------+--------------------

Server | Address | Port | Connections | Status

-------------------+-----------------+-------+-------------+--------------------

server1 | 192.168.128.125 | 3306 | 0 | Slave, Running

server2 | 192.168.128.126 | 3306 | 0 | Master, Running

server3 | 192.168.128.127 | 3306 | 0 | Slave, Running

server4 | 192.168.128.128 | 3306 | 0 | Slave, Running

-------------------+-----------------+-------+-------------+--------------------

测试

连接MaxScale# 连接监控服务器的maxscale服务

# -u: maxscale配置中[Read-Write-Service]模块下的user,即mysql中创建的路由用户

# -h: 监控服务器ip(没有启动mysql)

# -P: maxscale配置中[Read-Write-Listener]模块下的port,默认4406

mysql -uqvbilam_scale_route -pqvbilam -h192.168.128.129 -P3306

# 成功进入mysql界面

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 17

Server version: 5.7.25-log MySQL Community Server (GPL)

Copyright (c) 2000, 2020, Oracle and/or its affiliates. All rights reserved.

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 [(none)]>

读写分离

通过下面演示可以看到当执行读操作的时候,分配的主机名是qvbilam_mha_1(从库125),当执行事务也就是写操作的时候,分配的主机名为qvbilam_mha_2(主库126).# 测试读

MySQL [(none)]> select @@hostname;

+---------------+

| @@hostname |

+---------------+

| qvbilam_mha_1 |

+---------------+

1 row in set (0.01 sec)

# 测试写

MySQL [(none)]> begin;

Query OK, 0 rows affected (0.00 sec)

MySQL [(none)]> select @@hostname;

+---------------+

| @@hostname |

+---------------+

| qvbilam_mha_2 |

+---------------+

1 row in set (0.00 sec)

MySQL [(none)]> rollback;

Query OK, 0 rows affected (0.00 sec)