Mysql使用ProxySQL实现读写分离

Posted 2020-10-31

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：
  • 系统均为CentOS7.4，并且关闭防火墙和selinux
  • ProxySQL版本：proxysql-1.4.8-1-centos7.x86_64.rpm
  • Mysql版本：mariadb 5.5.56-2.el7
  • ProxySQL主机IP：192.168.100.2
  • Mysql主库IP：192.168.100.3
  • 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：
[[email protected] ~]#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

[[email protected] ~]#/etc/init.d/proxysql start
Starting ProxySQL: DONE!

[[email protected] ~]#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

[[email protected] ~]# 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‘,1,1);

#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

[[email protected] ~]#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)