ProxySQL实现读写分离

环境说明：

IP	角色	应用	系统平台
192.168.92.131	读写分离解析主机	proxysql	rhel8
192.168.92.129	master	mysql	rhel8
192.168.92.130	slave	mysql	rhel8

准备工作：

• 关闭防火墙
• 关闭SELINUX
• 安装mysql并配置主从

安装mysql并配置主从

//授权（master）
[root@master ~]# mysql -uroot -p123456

mysql> grant replication slave on *.* to 'repl'@'192.168.92.130' identified by '123456';
Query OK, 0 rows affected, 1 warning (0.00 sec)

mysql> flush privileges;
Query OK, 0 rows affected (0.01 sec)

//连接测试（slave）
[root@slave ~]# mysql -urepl -p123456 -h192.168.92.129
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 7
Server version: 5.7.31 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>

//更改配置文件（master）
[root@master ~]# vi /etc/my.cnf

[mysqld]
basedir=/usr/local/mysql
datadir=/opt/mydata
socket=/tmp/mysql.sock
port=3306
pid-file=/opt/mydata/mysql.pid
user=mysql
skip-name-resolve

server-id = 10
log-bin = mysql_bin

[root@master ~]# service mysqld restart
Shutting down MySQL.. SUCCESS! 
Starting MySQL. SUCCESS!

//更改配置文件（slave）
[root@slave ~]# vi /etc/my.cnf

[mysqld]
basedir=/usr/local/mysql
datadir=/opt/mydata
socket=/tmp/mysql.sock
port=3306
pid-file=/opt/mydata/mysql.pid
user=mysql
skip-name-resolve

server-id = 20
relay-log = myrelay

[root@slave ~]# service mysqld restart
Shutting down MySQL.. SUCCESS! 
Starting MySQL. SUCCESS!

//设置改变属主（slave）
mysql> change master to
    -> master_host='192.168.92.129',
    -> master_user='repl',
    -> master_password='123456',
    -> master_log_file='mysql_bin.000001',
    -> master_log_pos=154;
Query OK, 0 rows affected, 2 warnings (0.02 sec)

mysql> start slave;
Query OK, 0 rows affected (0.00 sec)

mysql> show slave statusG
。。。。。。
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
。。。。。。

配置ProxySQL

mysql主库添加proxysql可以增删改查的账号

//授权（master）
mysql> grant all on *.* to 'proxysql'@'192.168.92.131' ideentified by 'porxysql';
Query OK, 0 rows affected, 1 warning (0.00 sec)

mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)

//连接测试（proxy SQL）
[root@proxysql ~]# mysql -uproxysql -pproxysql -h192.168.92.129
ERROR 1045 (28000): Access denied for user 'proxysql'@'192.168.92.131' (using password: YES)
[root@proxysql ~]# mysql -uproxysql -pporxysql -h192.168.92.129
Welcome to the MariaDB monitor.  Commands end with ; or g.
Your MySQL connection id is 9
Server version: 5.7.31-log MySQL Community Server (GPL)

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)]> exit
Bye
[root@proxysql ~]# mysql -uproxysql -pporxysql -h192.168.92.130
Welcome to the MariaDB monitor.  Commands end with ; or g.
Your MySQL connection id is 5
Server version: 5.7.31 MySQL Community Server (GPL)

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)]>

登录proxysql管理端

[root@proxysql ~]# export MYSQL_PS1="(u@h:p) [d]> "
[root@proxysql ~]# mysql -uadmin -padmin -P7777 -h127.0.0.1
Welcome to the MariaDB monitor.  Commands end with ; or g.
Your MySQL connection id is 2
Server version: 5.5.30 (ProxySQL Admin Module)

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

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

(admin@127.0.0.1:7777) [(none)]>

proxysql管理端添加后端连接mysql主从数据库的配置

(admin@127.0.0.1:7777) [(none)]> insert into mysql_servers(hostgroup_id,hostname,port,weight,comment) values(100,'192.168.92.129',3306,1,'Write Group');
Query OK, 1 row affected (0.001 sec)

(admin@127.0.0.1:7777) [(none)]> insert into mysql_servers(hostgroup_id,hostname,port,weight,comment) values(200,'192.168.92.130',3306,1,'Read Group');
Query OK, 1 row affected (0.000 sec)

(admin@127.0.0.1:7777) [(none)]> select * from mysql_servers;
+--------------+----------------+------+-----------+--------+--------+-------------+-----------------+---------------------+---------+----------------+-------------+
| hostgroup_id | hostname       | port | gtid_port | status | weight | compression | max_connections | max_replication_lag | use_ssl | max_latency_ms | comment     |
+--------------+----------------+------+-----------+--------+--------+-------------+-----------------+---------------------+---------+----------------+-------------+
| 100          | 192.168.92.129 | 3306 | 0         | ONLINE | 1      | 0           | 1000            | 0                   | 0       | 0              | Write Group |
| 200          | 192.168.92.130 | 3306 | 0         | ONLINE | 1      | 0           | 1000            | 0                   | 0       | 0              | Read Group  |
+--------------+----------------+------+-----------+--------+--------+-------------+-----------------+---------------------+---------+----------------+-------------+
2 rows in set (0.000 sec)

//修改后，需要加载到RUNTIME，并保存到disk
(admin@127.0.0.1:7777) [(none)]> load mysql servers to runtime;
Query OK, 0 rows affected (0.006 sec)

(admin@127.0.0.1:7777) [(none)]> save mysql servers to disk;
Query OK, 0 rows affected (0.071 sec)

 在 proxysql 主机的 mysql_users 表中添加刚才在 master 上创建的账号 proxysql，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100;
当读写分离的路由规则不符合时，会访问默认组的数据库;

(admin@127.0.0.1:7777) [(none)]> insert into mysql_users(username,password,default_hostgroup,transaction_persistent) values('proxysql','proxysql',100,1);
Query OK, 1 row affected (0.000 sec)

(admin@127.0.0.1:7777) [(none)]> select * from mysql_users G
*************************** 1. row ***************************
              username: proxysql      用户名
              password: proxysql      密码
                active: 1             是否启用账户
               use_ssl: 0             
     default_hostgroup: 100           默认主
        default_schema: NULL
         schema_locked: 0
transaction_persistent: 1
          fast_forward: 0
               backend: 1
              frontend: 1
       max_connections: 10000         最大连接数
            attributes: 
               comment: 
1 row in set (0.000 sec)

//保存到dixk
(admin@127.0.0.1:7777) [(none)]> load mysql users to runtime;
Query OK, 0 rows affected (0.001 sec)

(admin@127.0.0.1:7777) [(none)]> save mysql users to disk;
Query OK, 0 rows affected (0.010 sec)

添加健康检测的帐号

在mysql的 master 端添加属于proxysql的只读账号

mysql> grant select on *.* to 'monitor'@'192.168.92.%' identified by 'monitor';
Query OK, 0 rows affected, 1 warning (0.00 sec)

mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)

在proxysql主机端修改变量设置健康检测的账号

(admin@127.0.0.1:7777) [(none)]> set mysql-monitor_username='monitor';
Query OK, 1 row affected (0.000 sec)

(admin@127.0.0.1:7777) [(none)]> set mysql-monitor_password='monitor';
Query OK, 1 row affected (0.000 sec)

(admin@127.0.0.1:7777) [(none)]> load mysql variables to runtime;
Query OK, 0 rows affected (0.002 sec)

(admin@127.0.0.1:7777) [(none)]> save mysql variables to disk;
Query OK, 140 rows affected (0.005 sec)

添加读写分离的路由规则

需求：

• 将 select 查询语句全部路由至 hostgroup_id=2 的组(也就是读组)
• 但是 select * from tb for update 这样的语句是会修改数据的，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)

(admin@127.0.0.1:7777) [(none)]> insert into mysql_query_rules(rule_id,active,match_digest,destination_hostgroup,apply) values(100,1,'^SELECT.*FOR UPDATE$',100,1);
Query OK, 1 row affected (0.001 sec)

(admin@127.0.0.1:7777) [(none)]> insert into mysql_query_rules(rule_id,active,match_digest,destination_hostgroup,apply) values(200,1,'^SELECT',200,1);
Query OK, 1 row affected (0.000 sec)

(admin@127.0.0.1:7777) [(none)]> select rule_id,active,match_digest,destination_hostgroup,apply from mysql_query_rules;
+---------+--------+----------------------+-----------------------+-------+
| rule_id | active | match_digest         | destination_hostgroup | apply |
+---------+--------+----------------------+-----------------------+-------+
| 100     | 1      | ^SELECT.*FOR UPDATE$ | 100                   | 1     |
| 200     | 1      | ^SELECT              | 200                   | 1     |
+---------+--------+----------------------+-----------------------+-------+
2 rows in set (0.000 sec)

(admin@127.0.0.1:7777) [(none)]> load mysql query rules to runtime;
Query OK, 0 rows affected (0.001 sec)

(admin@127.0.0.1:7777) [(none)]> save mysql query rules to disk;
Query OK, 0 rows affected (0.034 sec)

验证读写分离

登录 proxysql 客户端

登录用户是刚才我们在 mysql_user 表中创建的用户，端口为6033

[root@proxysql ~]# mysql -uproxysql -pproxysql -h127.0.0.1 -P6033
Welcome to the MariaDB monitor.  Commands end with ; or g.
Your MySQL connection id is 5
Server version: 5.5.30 (ProxySQL)

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

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

(proxysql@127.0.0.1:6033) [(none)]> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| school             |
| sys                |
+--------------------+
5 rows in set (0.006 sec)

尝试修改数据库和查询

创建2个数据库并查询一下表

(proxysql@127.0.0.1:6033) [(none)]> create database jinxinruntian;
Query OK, 1 row affected (0.007 sec)

(proxysql@127.0.0.1:6033) [(none)]> create database wangqing;
Query OK, 1 row affected (0.004 sec)

(proxysql@127.0.0.1:6033) [(none)]> select user,host from mysql.user;
+---------------+----------------+
| user          | host           |
+---------------+----------------+
| monitor       | 192.168.92.%   |
| repl          | 192.168.92.130 |
| proxysql      | 192.168.92.131 |
| mysql.session | localhost      |
| mysql.sys     | localhost      |
| root          | localhost      |
+---------------+----------------+
6 rows in set (0.003 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，其需要在proxysql管理端执行

(admin@127.0.0.1:7777) [(none)]> select * from stats_mysql_query_digestG
*************************** 1. row ***************************
        hostgroup: 200
       schemaname: information_schema
         username: proxysql
   client_address: 
           digest: 0x0F02B330C823D739
      digest_text: select user,host from mysql.user
       count_star: 1
       first_seen: 1623022307
        last_seen: 1623022307
         sum_time: 2953
         min_time: 2953
         max_time: 2953
sum_rows_affected: 0
    sum_rows_sent: 6
*************************** 2. row ***************************
        hostgroup: 100
       schemaname: information_schema
         username: proxysql
   client_address: 
           digest: 0xCE6BB7764BA98E04
      digest_text: create database jinxinruntian
       count_star: 1
       first_seen: 1623022295
        last_seen: 1623022295
         sum_time: 6590
         min_time: 6590
         max_time: 6590
sum_rows_affected: 1
    sum_rows_sent: 0
*************************** 3. row ***************************
        hostgroup: 100
       schemaname: none
         username: proxysql
   client_address: 
           digest: 0x99531AEFF718C501
      digest_text: show tables
       count_star: 1
       first_seen: 1623022281
        last_seen: 1623022281
         sum_time: 28595
         min_time: 28595
         max_time: 28595
sum_rows_affected: 0
    sum_rows_sent: 0
*************************** 4. row ***************************
        hostgroup: 200
       schemaname: school
         username: proxysql
   client_address: 
           digest: 0x620B328FE9D6D71A
      digest_text: SELECT DATABASE()
       count_star: 1
       first_seen: 1623022281
        last_seen: 1623022281
         sum_time: 2763
         min_time: 2763
         max_time: 2763
sum_rows_affected: 0
    sum_rows_sent: 1

从上面的 hostgroup 和 digest_text 值来看，所有的写操作都被路由至100组，读操作都被路由至200组，其中100组为写组，200组为读组！