一、proxysql介绍

• 读写分离
• 基于用户、schema、语句对SQL进行路由
• 缓存结果，减轻后端数据库服务器压力
• 健康状态检测

二、proxysql实现读写分离

1、环境描述

192.168.140.10 主库 MySQL 8.0
192.168.140.11 从库 MySQL 8.0
192.168.140.12 proxysql

2、两台数据库配置读写分离，从库添加read_only参数

3、安装proxysql

cat > /etc/yum.repos.d/proxysql.repo << EOF
[proxysql]
name=ProxySQL YUM repository
baseurl=https://repo.proxysql.com/ProxySQL/proxysql-2.6.x/centos/\$releasever
gpgcheck=1
gpgkey=https://repo.proxysql.com/ProxySQL/proxysql-2.6.x/repo_pub_key
EOF

[root@proxysql ~]# yum install -y proxysql mariadb[root@proxysql ~]# systemctl enable --now proxysql
[root@proxysql ~]# netstat -tunlp
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name    
tcp        0      0 0.0.0.0:6032            0.0.0.0:*               LISTEN      16544/proxysql      
tcp        0      0 0.0.0.0:6033            0.0.0.0:*               LISTEN      16544/proxysql 6032端口: proxysql管理端口，用于对Proxysql进行配置、状态查看
6033端口: proxysql业务连接端口

3.1 proxysql内置库说明

mysql> show databases;
+-----+---------------+-------------------------------------+
| seq | name          | file                                |
+-----+---------------+-------------------------------------+
| 0   | main          |                                     |
| 2   | disk          | /var/lib/proxysql/proxysql.db       |
| 3   | stats         |                                     |
| 4   | monitor       |                                     |
| 5   | stats_history | /var/lib/proxysql/proxysql_stats.db |
+-----+---------------+-------------------------------------+
5 rows in set (0.00 sec)说明：
1、main库，最主要的库，对proxysql进行配置大多数要修改main库中的表，为内存数据库，需要持久化保存
2、disk库， 和main库一致，是main库的持久化
3、stats库，统计信息库
4、monitor库，对后端服务器做健康状态检查的信息库
5、stats_history库，历史状态信息

3.2 main库中主要的表说明

mysql> show tables from main;
+----------------------------------------------------+
| tables                                             |
+----------------------------------------------------+
| coredump_filters                                   |
| global_variables                                   |
| mysql_aws_aurora_hostgroups                        |
| mysql_collations                                   |
| mysql_firewall_whitelist_rules                     |
| mysql_firewall_whitelist_sqli_fingerprints         |
| mysql_firewall_whitelist_users                     |
| mysql_galera_hostgroups                            |
| mysql_group_replication_hostgroups                 |
| mysql_hostgroup_attributes                         |
| mysql_query_rules                                  |     // 路由SQL语句的表
| mysql_query_rules_fast_routing                     |
| mysql_replication_hostgroups                       |
| mysql_servers                                      |	  // 存储后端数据库服务器连接信息的表
| mysql_servers_ssl_params                           |    
| mysql_users                                        |    // 存储连接后端数据库用户的表
| proxysql_servers                                   |
| restapi_routes                                     |
| runtime_checksums_values                           |
| runtime_coredump_filters                           |
| runtime_global_variables                           |
| runtime_mysql_aws_aurora_hostgroups                |
| runtime_mysql_firewall_whitelist_rules             |
| runtime_mysql_firewall_whitelist_sqli_fingerprints |
| runtime_mysql_firewall_whitelist_users             |
| runtime_mysql_galera_hostgroups                    |
| runtime_mysql_group_replication_hostgroups         |
| runtime_mysql_hostgroup_attributes                 |
| runtime_mysql_query_rules                          |
| runtime_mysql_query_rules_fast_routing             |
| runtime_mysql_replication_hostgroups               |
| runtime_mysql_servers                              |
| runtime_mysql_servers_ssl_params                   |
| runtime_mysql_users                                |
| runtime_proxysql_servers                           |
| runtime_restapi_routes                             |
| runtime_scheduler                                  |
| scheduler                                          |
+----------------------------------------------------+
38 rows in set (0.01 sec)

4、在后端主库创建允许proxysql连接的用户

mysql> CREATE USER 'proxyuser'@"192.168.183.12" identified by 'WWW.1.com';
Query OK, 0 rows affected (0.02 sec)mysql> GRANT all ON *.* TO 'proxyuser'@'192.168.183.12';
Query OK, 0 rows affected (0.00 sec)mysql> FLUSH PRIVILEGES;
Query OK, 0 rows affected (0.00 sec)

5、在proxysql上添加后端服务器信息、并指定读、写组

[root@proxysql ~]# mysql -uadmin -padmin -h 127.0.0.1 -P 6032mysql> show databases;
+-----+---------------+-------------------------------------+
| seq | name          | file                                |
+-----+---------------+-------------------------------------+
| 0   | main          |                                     |
| 2   | disk          | /var/lib/proxysql/proxysql.db       |
| 3   | stats         |                                     |
| 4   | monitor       |                                     |
| 5   | stats_history | /var/lib/proxysql/proxysql_stats.db |
+-----+---------------+-------------------------------------+
5 rows in set (0.00 sec)mysql> insert into mysql_servers(hostgroup_id,hostname,port,weight,comment) values(1, "192.168.183.10",3306,1,"write group");
Query OK, 1 row affected (0.00 sec)mysql> insert into mysql_servers(hostgroup_id,hostname,port,weight,comment) values(2, "192.168.183.11",3306,1,"read group");
Query OK, 1 row affected (0.00 sec)mysql> select * from mysql_servers;
+--------------+----------------+------+-----------+--------+--------+-------------+-----------------+---------------------+---------+----------------+-------------+
| hostgroup_id | hostname       | port | gtid_port | status | weight | compression | max_connections | max_replication_lag | use_ssl | max_latency_ms | comment     |
+--------------+----------------+------+-----------+--------+--------+-------------+-----------------+---------------------+---------+----------------+-------------+
| 1            | 192.168.183.10 | 3306 | 0         | ONLINE | 1      | 0           | 1000            | 0                   | 0       | 0              | write group |
| 2            | 192.168.183.11 | 3306 | 0         | ONLINE | 1      | 0           | 1000            | 0                   | 0       | 0              | read group  |
+--------------+----------------+------+-----------+--------+--------+-------------+-----------------+---------------------+---------+----------------+-------------+
2 rows in set (0.00 sec)说明：
数字1代表写组
数字2代表读组mysql> load mysql servers to runtime;
Query OK, 0 rows affected (0.00 sec)mysql> save mysql servers to disk;
Query OK, 0 rows affected (0.02 sec)

6、在Proxysql上添加连接后端数据库的用户

mysql> insert into mysql_users(username,password,default_hostgroup,transaction_persistent) values("proxyuser","WWW.1.com",1,1);
Query OK, 1 row affected (0.00 sec)mysql> select * from mysql_users;
+-----------+-----------+--------+---------+-------------------+----------------+---------------+------------------------+--------------+---------+----------+-----------------+------------+---------+
| username  | password  | active | use_ssl | default_hostgroup | default_schema | schema_locked | transaction_persistent | fast_forward | backend | frontend | max_connections | attributes | comment |
+-----------+-----------+--------+---------+-------------------+----------------+---------------+------------------------+--------------+---------+----------+-----------------+------------+---------+
| proxyuser | WWW.1.com | 1      | 0       | 1                 | NULL           | 0             | 1                      | 0            | 1       | 1        | 10000           |            |         |
+-----------+-----------+--------+---------+-------------------+----------------+---------------+------------------------+--------------+---------+----------+-----------------+------------+---------+
1 row in set (0.00 sec)mysql> load mysql users to runtime;
Query OK, 0 rows affected (0.00 sec)mysql> save mysql users to disk;
Query OK, 0 rows affected (0.01 sec)

7、在proxysql添加健康状态检查的用户

7.1 在后端主库创建健康状态检查用户

mysql> CREATE USER 'healthuser'@"%" IDENTIFIED BY 'WWW.1.com';
Query OK, 0 rows affected (0.00 sec)mysql> GRANT select ON *.* TO 'healthuser'@"%";
Query OK, 0 rows affected (0.00 sec)mysql> FLUSH PRIVILEGES;
Query OK, 0 rows affected (0.00 sec)

7.2 proxysql上添加该用户

mysql> set mysql-monitor_username="healthuser";
Query OK, 1 row affected (0.00 sec)mysql> set mysql-monitor_password="WWW.1.com";
Query OK, 1 row affected (0.01 sec)mysql> load mysql variables to runtime;
Query OK, 0 rows affected (0.01 sec)mysql> save mysql variables to disk;
Query OK, 162 rows affected (0.00 sec)

8、添加读写分离的路由规则

mysql> insert into mysql_query_rules(rule_id,active,match_digest,destination_hostgroup,apply) values(1,1,"^SELECT.*FOR UPDATE$
",1,1);
Query OK, 1 row affected (0.00 sec)mysql> insert into mysql_query_rules(rule_id,active,match_digest,destination_hostgroup,apply) values(2,1,"^SELECT",2,1);
Query OK, 1 row affected (0.00 sec)mysql> 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)mysql> load mysql query rules to runtime;
Query OK, 0 rows affected (0.00 sec)mysql> load admin variables to runtime;
Query OK, 0 rows affected (0.00 sec)mysql> save mysql query rules to disk;
Query OK, 0 rows affected (0.01 sec)mysql> save admin variables to disk;
Query OK, 49 rows affected (0.01 sec)

9、测试读写分离

9.1 登录Proxysql业务端，任意执行读写操作

[root@proxysql ~]# mysql -uproxyuser -pWWW.1.com -h 127.0.0.1 -P6033
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 2
Server version: 5.5.30 (ProxySQL)Copyright (c) 2000, 2024, 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> 
mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| sys                |
+--------------------+
4 rows in set (0.01 sec)mysql> create database test1;
Query OK, 1 row affected (0.01 sec)mysql> create database test2;
Query OK, 1 row affected (0.01 sec)mysql> select user,host from mysql.user;
+------------------+----------------+
| user             | host           |
+------------------+----------------+
| healthuser       | %              |
| repluser         | %              |
| proxyuser        | 192.168.183.12 |
| mysql.infoschema | localhost      |
| mysql.session    | localhost      |
| mysql.sys        | localhost      |
| root             | localhost      |
+------------------+----------------+
7 rows in set (0.00 sec)mysql> 

9.2 登录proxysql管理端，通过hostgroup_id查看读写分离效果

mysql> select * from stats_mysql_query_digest;
+-----------+--------------------+-----------+----------------+--------------------+----------------------------------+------------+------------+------------+----------+----------+----------+-------------------+---------------+
| hostgroup | schemaname         | username  | client_address | digest             | digest_text                      | count_star | first_seen | last_seen  | sum_time | min_time | max_time | sum_rows_affected | sum_rows_sent |
+-----------+--------------------+-----------+----------------+--------------------+----------------------------------+------------+------------+------------+----------+----------+----------+-------------------+---------------+
| 2         | information_schema | proxyuser |                | 0xf02b330c823d739  | select user,host from mysql.user | 1          | 1719230970 | 1719230970 | 5030     | 5030     | 5030     | 0                 | 7             |
| 1         | information_schema | proxyuser |                | 0x5b29ed96765bad6c | create database test2            | 1          | 1719230951 | 1719230951 | 7884     | 7884     | 7884     | 1                 | 0             |
| 1         | information_schema | proxyuser |                | 0xec77b5d4dcabfb9f | create database test1            | 1          | 1719230948 | 1719230948 | 4983     | 4983     | 4983     | 1                 | 0             |
| 1         | information_schema | proxyuser |                | 0x2033e45904d3df0  | show databases                   | 1          | 1719230934 | 1719230934 | 12909    | 12909    | 12909    | 0                 | 4             |
| 1         | information_schema | proxyuser |                | 0x226cd90d52a2ba0b | select @@version_comment limit ? | 1          | 1719230929 | 1719230929 | 0        | 0        | 0        | 0                 | 0             |
+-----------+--------------------+-----------+----------------+--------------------+----------------------------------+------------+------------+------------+----------+----------+----------+-------------------+---------------+
5 rows in set (0.02 sec)