转载文献：
https://blog.51cto.com/bigboss/2103290
ProxySQL简介：
• ProxySQL是一个高性能的MySQL中间件，拥有强大的规则引擎。
• 详细的中文介绍：别人写的，基本跟官方无差别
• 官方文档：https://github.com/sysown/proxysql/wiki/
• 下载地址：https://github.com/sysown/proxysql/releases
准备工作
• 本文所用环境：
o 系统均为CentOS7.4，并且关闭防火墙和selinux
o ProxySQL版本：proxysql-1.4.8-1-centos7.x86_64.rpm
o Mysql版本：mariadb 5.5.56-2.el7
o ProxySQL主机IP：192.168.100.2
o Mysql主库IP：192.168.100.3
o Mysql从库IP：192.168.100.4
• 前提条件： Mysql主从已经配置好了同步
开始安装ProxySQL
• 安装ProxySQL：
wget https://github.com/sysown/proxysql/releases/download/v1.4.8/proxysql-1.4.8-1-centos7.x86_64.rpm
yum install -y proxysql-1.4.8-1-centos7.x86_64.rpm
#proxysql需要依赖一些perl库，所以使用yum安装
#安装生成的文件：
[root@ProxySQL ~]#rpm -ql proxysql
/etc/init.d/proxysql #启动脚本
/etc/proxysql.cnf #配置文件，仅在第一次(/var/lib/proxysql/proxysql.db文件不存在)启动时有效
#启动后可以在proxysql管理端中通过修改数据库的方式修改配置并生效(官方推荐方式。)
/usr/bin/proxysql #主程序文件
/usr/share/proxysql/tools/proxysql_galera_checker.sh
/usr/share/proxysql/tools/proxysql_galera_writer.pl
• 启动proxysql：
/etc/init.d/proxysql start
#proxysql客户端监听在6033端口上，管理端监听6032端口
[root@ProxySQL ~]#/etc/init.d/proxysql start
Starting ProxySQL: DONE!
[root@ProxySQL ~]#ss -tanl
State Recv-Q Send-Q Local Address:Port Peer Address:Port
LISTEN 0 128 :6032 :
LISTEN 0 128 :6033 :
LISTEN 0 128 :6033 :
LISTEN 0 128 :6033 :
LISTEN 0 128 :6033 :*
• 连接proxysql管理端进行配置：
mysql -uadmin -padmin -h127.0.0.1 -P6032
#默认的管理端账号密码都是admin，登录进去之后可以修改变量进行修改账号密码
[root@ProxySQL ~]# mysql -uadmin -padmin -h127.0.0.1 -P6032
Welcome to the MariaDB monitor. Commands end with ; or \g.
Your MySQL connection id is 1
Server version: 5.5.30 (ProxySQL Admin Module)
Copyright (c) 2000, 2017, Oracle, MariaDB Corporation Ab and others.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
MySQL [(none)]>
• 添加后端的mysql主机：
insert into mysql_servers(hostgroup_id,hostname,port,weight,comment) values(1,'192.168.100.3',3306,1,'Write Group');
insert into mysql_servers(hostgroup_id,hostname,port,weight,comment) values(2,'192.168.100.4',3306,1,'Read Group');
#使用insert语句添加主机到mysql_servers表中，其中：hostgroup_id 1 表示写组，2表示读组。
MySQL [(none)]> select from mysql_servers;
+--------------+---------------+------+--------+--------+-------------+-----------------+---------------------+--
| hostgroup_id | hostname | port | status | weight | compression | max_connections | max_replication_lag | u
+--------------+---------------+------+--------+--------+-------------+-----------------+---------------------+--
| 1 | 192.168.100.3 | 3306 | ONLINE | 1 | 0 | 1000 | 0 | 0
| 2 | 192.168.100.4 | 3306 | ONLINE | 1 | 0 | 1000 | 0 | 0
+--------------+---------------+------+--------+--------+-------------+-----------------+---------------------+--
2 rows in set (0.00 sec)
• 添加可以访问后端主机的账号：
GRANT ALL ON .* TO 'proxysql'@'192.168.100.%' IDENTIFIED BY '123456';
#在后端mysql中添加可以增删改查的账号
insert into mysql_users(username,password,default_hostgroup,transaction_persistent)values('proxysql','123456',1,1);
#在proxysql主机的mysql_users表中添加刚才创建的账号，proxysql客户端需要使用这个账号来访问数据库。
#default_hostgroup默认组设置为写组，也就是1
#当读写分离的路由规则不符合时，会访问默认组的数据库
MySQL [(none)]> insert into mysql_users(username,password,default_hostgroup,transaction_persistent)values('proxysql','123456',1,1);
Query OK, 1 row affected (0.00 sec)
MySQL [(none)]> select * from mysql_users\G
1. row
username: proxysql
password: 123456
active: 1
use_ssl: 0
default_hostgroup: 1
default_schema: NULL
schema_locked: 0
transaction_persistent: 1
fast_forward: 0
backend: 1
frontend: 1
max_connections: 10000
1 row in set (0.00 sec)
• 添加健康监测的账号：
GRANT SELECT ON . TO 'monitor'@'192.168.100.%' IDENTIFIED BY 'monitor';
#在后端主机中添加可以访问数据库的账号,SELECT权限即可
set mysql-monitor_username='monitor'
set mysql-monitor_password='monitor'
#在proxysql管理端中修改变量设置健康检测的账号
• 添加读写分离的路由规则：
insert into mysql_query_rules(rule_id,active,match_digest,destination_hostgroup,apply)values(1,1,'^SELECT.*FOR UPDATE$',1,1);
insert into mysql_query_rules(rule_id,active,match_digest,destination_hostgroup,apply)values(2,1,'^SELECT',2,1);
#将select语句全部路由至hostgroup_id=2的组(也就是读组)
#但是select * from tb for update这样的语句是修改数据的，所以需要单独定义，将它路由至hostgroup_id=1的组(也就是写组)
#其他没有被规则匹配到的组将会被路由至用户默认的组(mysql_users表中的default_hostgroup)
MySQL [(none)]> select rule_id,active,match_digest,destination_hostgroup,apply from mysql_query_rules;
+---------+--------+----------------------+-----------------------+-------+
| rule_id | active | match_digest | destination_hostgroup | apply |
+---------+--------+----------------------+-----------------------+-------+
| 1 | 1 | ^SELECT.*FOR UPDATE$ | 1 | 1 |
| 2 | 1 | ^SELECT | 2 | 1 |
+---------+--------+----------------------+-----------------------+-------+
2 rows in set (0.00 sec)
• 将刚才我们修改的数据加载至RUNTIME中(参考ProxySQL的多层配置结构)：
load mysql users to runtime;
load mysql servers to runtime;
load mysql query rules to runtime;
load mysql variables to runtime;
load admin variables to runtime;
#load进runtime，是配置生效
save mysql users to disk;
save mysql servers to disk;
save mysql query rules to disk;
save mysql variables to disk;
save admin variables to disk;
#save到磁盘(/var/lib/proxysql/proxysql.db)中，永久保存配置
MySQL [(none)]> load mysql users to runtime;
Query OK, 0 rows affected (0.00 sec)
... ...
... ...
MySQL [(none)]> save admin variables to disk;
Query OK, 31 rows affected (0.01 sec)
测试读写分离
• 连接proxysql客户端:
mysql -uproxysql -p123456 -h127.0.0.1 -P6033
#登录用户是刚才我们在mysql_user表中创建的用户，端口为6033
[root@centos7 ~]#mysql -uproxysql -p123456 -h127.0.0.1 -P6033
Welcome to the MariaDB monitor. Commands end with ; or \g.
Your MySQL connection id is 4
Server version: 5.5.30 (ProxySQL)
Copyright (c) 2000, 2017, 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 |
+--------------------+
| information_schema |
| mysql |
| performance_schema |
| test |
+--------------------+
4 rows in set (0.00 sec)
MySQL [(none)]>
• 尝试修改数据库和查询：
create database bigboss;
create database weijinyun;
select user,host from mysql.user;
#创建两个数据库和查个表。
MySQL [(none)]> create database bigboss;
Query OK, 1 row affected (0.01 sec)
MySQL [(none)]> create database weijinyun;
Query OK, 1 row affected (0.00 sec)
MySQL [(none)]> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| bigboss |
| mysql |
| performance_schema |
| test |
| weijinyun |
+--------------------+
6 rows in set (0.01 sec)
MySQL [(none)]> select user,host from mysql.user;
+-------------+---------------+
| user | host |
+-------------+---------------+
| root | 127.0.0.1 |
| monitor | 192.168.100.% |
| proxysql | 192.168.100.% |
| repliaction | 192.168.100.% |
| root | ::1 |
| | centos7 |
| root | centos7 |
| | localhost |
| root | localhost |
+-------------+---------------+
9 rows in set (0.01 sec)
• 验证读写分离是否成功：
#proxysql有个类似审计的功能，可以查看各类SQL的执行情况。在proxysql管理端执行：
select * from stats_mysql_query_digest;
#从下面的hostgroup和digest_text值来看，所有的写操作都被路由至1组，读操作都被路由至2组，
#其中1组为写组，2组为读组！
#读写分离成功！！！
MySQL [(none)]> select * from stats_mysql_query_digest;
+-----------+--------------------+----------+--------------------+----------------------------------+------------+------------+------------+----------+----------+----------+
| hostgroup | schemaname | username | digest | digest_text | count_star | first_seen | last_seen | sum_time | min_time | max_time |
+-----------+--------------------+----------+--------------------+----------------------------------+------------+------------+------------+----------+----------+----------+
| 1 | information_schema | proxysql | 0xA6212D89D814BAC5 | create database weijinyun | 1 | 1523658457 | 1523658457 | 1244 | 1244 | 1244 |
| 2 | information_schema | proxysql | 0x0F02B330C823D739 | select user,host from mysql.user | 1 | 1523658520 | 1523658520 | 12538 | 12538 | 12538 |
| 1 | information_schema | proxysql | 0x02033E45904D3DF0 | show databases | 5 | 1523658103 | 1523658486 | 24852 | 1263 | 17592 |
| 1 | information_schema | proxysql | 0xA175FD2982EC6396 | create database bigboss | 1 | 1523658437 | 1523658437 | 1833 | 1833 | 1833 |
| 1 | information_schema | proxysql | 0x226CD90D52A2BA0B | select @@version_comment limit ? | 3 | 1523658098 | 1523658473 | 0 | 0 | 0 |
+-----------+--------------------+----------+--------------------+----------------------------------+------------+------------+------------+----------+----------+----------+
6 rows in set (0.00 sec)
转载文献：
https://blog.51cto.com/bigboss/2103290