ProxySQL（五）—— 代理多组独立的 MySQL 主从实例

要在一个 ProxySQL 实例里代理多组独立 MySQL 主从，核心思路是：给每组主从分配唯一、不重叠的 HostGroup（写组 + 读组），用 mysql_replication_hostgroups 绑定每组的写 / 读组，再通过用户默认组 + 查询路由规则隔离流量。下面从规划、配置、验证、故障切换四步完整落地。

一、环境说明

MySQL 版本 8.0.22
ProxySQL 版本 2.6.5（最稳定。代理多套主机组时，2.7.3 有 bug）
第一组主从：
- 主： 172.18.3.122:18251
- 从1：172.18.3.232:18251
- 从2：172.18.4.109:18251
第二组主从：
- 主： 172.18.3.232:18252
- 从1：172.18.3.122:18252
- 从2：172.18.4.109:18252
每组主从都启用半同步复制、GTID、AUTO_POSITION

已经在 ProxySQL 中配置了第一组主从的主机组和查询规则：

sql 复制代码

Admin> SELECT hostgroup_id, status, hostname, port, weight, max_connections, max_replication_lag FROM mysql_servers;
+--------------+--------+--------------+-------+--------+-----------------+---------------------+
| hostgroup_id | status | hostname     | port  | weight | max_connections | max_replication_lag |
+--------------+--------+--------------+-------+--------+-----------------+---------------------+
| 1            | ONLINE | 172.18.4.109 | 18251 | 1      | 1000            | 60                  |
| 2            | ONLINE | 172.18.3.122 | 18251 | 1      | 1000            | 60                  |
| 1            | ONLINE | 172.18.3.122 | 18251 | 1      | 1000            | 60                  |
| 1            | ONLINE | 172.18.3.232 | 18251 | 1      | 1000            | 60                  |
+--------------+--------+--------------+-------+--------+-----------------+---------------------+
4 rows in set (0.00 sec)

Admin> SELECT hostgroup_id, status, hostname, port, weight, max_connections, max_replication_lag FROM runtime_mysql_servers;
+--------------+--------+--------------+-------+--------+-----------------+---------------------+
| hostgroup_id | status | hostname     | port  | weight | max_connections | max_replication_lag |
+--------------+--------+--------------+-------+--------+-----------------+---------------------+
| 1            | ONLINE | 172.18.3.122 | 18251 | 1      | 1000            | 60                  |
| 2            | ONLINE | 172.18.3.122 | 18251 | 1      | 1000            | 60                  |
| 2            | ONLINE | 172.18.3.232 | 18251 | 1      | 1000            | 60                  |
| 2            | ONLINE | 172.18.4.109 | 18251 | 1      | 1000            | 60                  |
+--------------+--------+--------------+-------+--------+-----------------+---------------------+
4 rows in set (0.00 sec)

Admin> SELECT rule_id, active, match_digest, destination_hostgroup, apply  FROM mysql_query_rules  ORDER BY rule_id;
+---------+--------+-----------------------------+-----------------------+-------+
| rule_id | active | match_digest                | destination_hostgroup | apply |
+---------+--------+-----------------------------+-----------------------+-------+
| 1       | 1      | ^INSERT                     | 1                     | 1     |
| 2       | 1      | ^UPDATE                     | 1                     | 1     |
| 3       | 1      | ^DELETE                     | 1                     | 1     |
| 4       | 1      | ^REPLACE                    | 1                     | 1     |
| 5       | 1      | ^MERGE                      | 1                     | 1     |
| 10      | 1      | ^CREATE                     | 1                     | 1     |
| 11      | 1      | ^ALTER                      | 1                     | 1     |
| 12      | 1      | ^DROP                       | 1                     | 1     |
| 13      | 1      | ^TRUNCATE                   | 1                     | 1     |
| 14      | 1      | ^RENAME                     | 1                     | 1     |
| 15      | 1      | ^GRANT                      | 1                     | 1     |
| 16      | 1      | ^REVOKE                     | 1                     | 1     |
| 20      | 1      | ^SELECT.*FOR UPDATE         | 1                     | 1     |
| 21      | 1      | ^SELECT.*LOCK IN SHARE MODE | 1                     | 1     |
| 100     | 1      | ^SELECT                     | 2                     | 1     |
+---------+--------+-----------------------------+-----------------------+-------+
15 rows in set (0.00 sec)

下面在 ProxySQL 中添加第二组 MySQL 主从实例，同样实现这组的读写分离和读负载均衡（一写三读）。

二、核心规划

关键：每组独立 HostGroup。每组主从必须用专属、不重复的写组 (writer HG)、读组 (reader HG)，避免互相干扰。

集群 A（业务 A）：写组 = 1，读组 = 2
集群 B（业务 B）：写组 = 3，读组 = 4

三、前置准备

1. 在 MySQL 实例创建用户

（1）监控用户

ProxySQL 健康检查用：

sql 复制代码

-- 在 172.18.3.232:18252 执行
CREATE USER monitor IDENTIFIED BY 'monitor';
GRANT USAGE, REPLICATION CLIENT ON *.* TO monitor;

（2）业务用户

ProxySQL 连接集群用。注意 ProxySQL 不允许相同用户名同时给多个集群用，因此这里注意不同集群的业务用户不要重名。

sql 复制代码

CREATE USER wxy_2 IDENTIFIED BY '123456';
GRANT all ON *.* TO wxy_2;

2. 主从状态规范

主库：read_only=0, super_read_only=0（可写）
从库：read_only=1, super_read_only=1（只读）

ProxySQL 靠 read_only 自动识别主/从、切换 HostGroup。

四、ProxySQL 配置（Admin 端口 6032）

1. 连接 ProxySQL Admin

bash 复制代码

mysql -u admin -padmin -h 127.0.0.1 -P6032 --prompt='ProxySQL Admin> '

2. 配置监控账号（全局生效）

这里已经在代理第一组主从时配置好：

sql 复制代码

Admin> select * from global_variables where variable_name in ('mysql-monitor_username','mysql-monitor_password');
+------------------------+----------------+
| variable_name          | variable_value |
+------------------------+----------------+
| mysql-monitor_password | monitor        |
| mysql-monitor_username | monitor        |
+------------------------+----------------+
2 rows in set (0.00 sec)

如果需要新配则执行：

sql 复制代码

UPDATE global_variables SET variable_value='monitor' WHERE variable_name='mysql-monitor_username';
UPDATE global_variables SET variable_value='monitor' WHERE variable_name='mysql-monitor_password';
LOAD MYSQL VARIABLES TO RUNTIME;
SAVE MYSQL VARIABLES TO DISK;

3. 添加 MySQL 服务器到 mysql_servers

添加第二组实例。

sql 复制代码

-- 集群B：主（172.18.3.232:18252）、从1（172.18.3.122:18252）、从2（172.18.4.109:18252）
INSERT INTO mysql_servers(hostgroup_id,hostname,port,comment) VALUES (3,'172.18.3.232',18252,'Cluster2-Master');
INSERT INTO mysql_servers(hostgroup_id,hostname,port,comment) VALUES (3,'172.18.3.122',18252,'Cluster2-Slave1');
INSERT INTO mysql_servers(hostgroup_id,hostname,port,comment) VALUES (3,'172.18.4.109',18252,'Cluster2-Slave2');

4. 配置复制 HostGroup

核心：绑定每组写/读组。

sql 复制代码

-- 集群B：写3、读4
INSERT INTO mysql_replication_hostgroups(writer_hostgroup,reader_hostgroup,check_type,comment)
VALUES (3,4,'read_only','Cluster2-Replication');

-- 手动把主库加入读组 4（永久生效，不会被自动模式覆盖）
INSERT INTO mysql_servers (hostgroup_id, hostname, port)
VALUES (4, '172.18.3.232', 18252);

LOAD MYSQL SERVERS TO RUNTIME;
SAVE MYSQL SERVERS TO DISK;

确认生效：

sql 复制代码

Admin> SELECT hostgroup_id, hostname, port, status
    ->   FROM runtime_mysql_servers
    ->  ORDER BY hostgroup_id, hostname;
+--------------+--------------+-------+--------+
| hostgroup_id | hostname     | port  | status |
+--------------+--------------+-------+--------+
| 1            | 172.18.3.122 | 18251 | ONLINE |
| 2            | 172.18.3.122 | 18251 | ONLINE |
| 2            | 172.18.3.232 | 18251 | ONLINE |
| 2            | 172.18.4.109 | 18251 | ONLINE |
| 3            | 172.18.3.232 | 18252 | ONLINE |
| 4            | 172.18.3.122 | 18252 | ONLINE |
| 4            | 172.18.3.232 | 18252 | ONLINE |
| 4            | 172.18.4.109 | 18252 | ONLINE |
+--------------+--------------+-------+--------+
8 rows in set (0.00 sec)

5. 配置业务用户

按集群隔离，默认路由到对应写组。

sql 复制代码

-- 业务B用户：默认走集群B写组3
INSERT INTO mysql_users(username,password,default_hostgroup,comment)
VALUES ('wxy_2','123456',3,'ClusterB-User');

LOAD MYSQL USERS TO RUNTIME;
SAVE MYSQL USERS TO DISK;

6. 配置查询路由规则

读写分离，每组独立。

sql 复制代码

UPDATE mysql_users SET default_hostgroup=3 where username='wxy_2';
LOAD MYSQL USERS TO RUNTIME;

sql 复制代码

-- 插入生产级完整规则
INSERT INTO mysql_query_rules (rule_id,active,match_digest,destination_hostgroup,apply) 
VALUES 
 
-- 所有写操作 DML
(31,1,'^INSERT',3,1),
(32,1,'^UPDATE',3,1),
(33,1,'^DELETE',3,1),
(34,1,'^REPLACE',3,1),
(35,1,'^MERGE',3,1),
 
-- 所有 DDL 操作
(40,1,'^CREATE',3,1),
(41,1,'^ALTER',3,1),
(42,1,'^DROP',3,1),
(43,1,'^TRUNCATE',3,1),
(44,1,'^RENAME',3,1),
(45,1,'^GRANT',3,1),
(46,1,'^REVOKE',3,1),
 
-- 锁查询强制主库
(50,1,'^SELECT.*FOR UPDATE',3,1),
(51,1,'^SELECT.*LOCK IN SHARE MODE',3,1),
 
-- 普通查询走读组 3台负载
(200,1,'^SELECT',4,1);

-- 一定要绑定用户
update mysql_query_rules set username='wxy' where destination_hostgroup in (1,2);
update mysql_query_rules set username='wxy_2' where destination_hostgroup in (3,4);

-- 加载并保存
LOAD MYSQL QUERY RULES TO RUNTIME;
SAVE MYSQL QUERY RULES TO DISK;

7. 加载所有配置到运行时、持久化到磁盘

sql 复制代码

LOAD MYSQL VARIABLES TO RUNTIME;
LOAD MYSQL SERVERS TO RUNTIME;
LOAD MYSQL USERS TO RUNTIME;
LOAD MYSQL QUERY RULES TO RUNTIME;

SAVE MYSQL VARIABLES TO DISK;
SAVE MYSQL SERVERS TO DISK;
SAVE MYSQL USERS TO DISK;
SAVE MYSQL QUERY RULES TO DISK;

五、验证配置（关键检查项）

1. 查看服务器分组与状态

sql 复制代码

Admin> SELECT hostgroup_id,hostname,port,status,comment FROM mysql_servers ORDER BY hostgroup_id;
+--------------+--------------+-------+--------+-----------------+
| hostgroup_id | hostname     | port  | status | comment         |
+--------------+--------------+-------+--------+-----------------+
| 1            | 172.18.3.122 | 18251 | ONLINE |                 |
| 1            | 172.18.3.232 | 18251 | ONLINE |                 |
| 1            | 172.18.4.109 | 18251 | ONLINE |                 |
| 2            | 172.18.3.122 | 18251 | ONLINE |                 |
| 3            | 172.18.3.122 | 18252 | ONLINE | Cluster2-Slave1 |
| 3            | 172.18.3.232 | 18252 | ONLINE | Cluster2-Master |
| 3            | 172.18.4.109 | 18252 | ONLINE | Cluster2-Slave2 |
| 4            | 172.18.3.232 | 18252 | ONLINE |                 |
+--------------+--------------+-------+--------+-----------------+
8 rows in set (0.00 sec)

Admin> SELECT hostgroup_id,hostname,port,status,comment FROM runtime_mysql_servers ORDER BY hostgroup_id;
+--------------+--------------+-------+--------+-----------------+
| hostgroup_id | hostname     | port  | status | comment         |
+--------------+--------------+-------+--------+-----------------+
| 1            | 172.18.3.122 | 18251 | ONLINE |                 |
| 2            | 172.18.3.122 | 18251 | ONLINE |                 |
| 2            | 172.18.3.232 | 18251 | ONLINE |                 |
| 2            | 172.18.4.109 | 18251 | ONLINE |                 |
| 3            | 172.18.3.232 | 18252 | ONLINE | Cluster2-Master |
| 4            | 172.18.3.122 | 18252 | ONLINE | Cluster2-Slave1 |
| 4            | 172.18.3.232 | 18252 | ONLINE |                 |
| 4            | 172.18.4.109 | 18252 | ONLINE | Cluster2-Slave2 |
+--------------+--------------+-------+--------+-----------------+
8 rows in set (0.01 sec)

主库应在写组 (1/3)、read_only=0
从库应在读组 (2/4)、read_only=1
状态应为ONLINE

2. 查看复制 HostGroup 绑定

sql 复制代码

Admin> SELECT * FROM mysql_replication_hostgroups;
+------------------+------------------+------------+----------------------+
| writer_hostgroup | reader_hostgroup | check_type | comment              |
+------------------+------------------+------------+----------------------+
| 1                | 2                | read_only  | cluster1             |
| 3                | 4                | read_only  | Cluster2-Replication |
+------------------+------------------+------------+----------------------+
2 rows in set (0.00 sec)

3. 查看查询规则

sql 复制代码

ProxySQL Admin> select rule_id,active,match_digest,destination_hostgroup,apply,username from runtime_mysql_query_rules;
+---------+--------+-----------------------------+-----------------------+-------+----------+
| rule_id | active | match_digest                | destination_hostgroup | apply | username |
+---------+--------+-----------------------------+-----------------------+-------+----------+
| 1       | 1      | ^INSERT                     | 1                     | 1     | wxy      |
| 2       | 1      | ^UPDATE                     | 1                     | 1     | wxy      |
| 3       | 1      | ^DELETE                     | 1                     | 1     | wxy      |
| 4       | 1      | ^REPLACE                    | 1                     | 1     | wxy      |
| 5       | 1      | ^MERGE                      | 1                     | 1     | wxy      |
| 10      | 1      | ^CREATE                     | 1                     | 1     | wxy      |
| 11      | 1      | ^ALTER                      | 1                     | 1     | wxy      |
| 12      | 1      | ^DROP                       | 1                     | 1     | wxy      |
| 13      | 1      | ^TRUNCATE                   | 1                     | 1     | wxy      |
| 14      | 1      | ^RENAME                     | 1                     | 1     | wxy      |
| 15      | 1      | ^GRANT                      | 1                     | 1     | wxy      |
| 16      | 1      | ^REVOKE                     | 1                     | 1     | wxy      |
| 20      | 1      | ^SELECT.*FOR UPDATE         | 1                     | 1     | wxy      |
| 21      | 1      | ^SELECT.*LOCK IN SHARE MODE | 1                     | 1     | wxy      |
| 31      | 1      | ^INSERT                     | 3                     | 1     | wxy_2    |
| 32      | 1      | ^UPDATE                     | 3                     | 1     | wxy_2    |
| 33      | 1      | ^DELETE                     | 3                     | 1     | wxy_2    |
| 34      | 1      | ^REPLACE                    | 3                     | 1     | wxy_2    |
| 35      | 1      | ^MERGE                      | 3                     | 1     | wxy_2    |
| 40      | 1      | ^CREATE                     | 3                     | 1     | wxy_2    |
| 41      | 1      | ^ALTER                      | 3                     | 1     | wxy_2    |
| 42      | 1      | ^DROP                       | 3                     | 1     | wxy_2    |
| 43      | 1      | ^TRUNCATE                   | 3                     | 1     | wxy_2    |
| 44      | 1      | ^RENAME                     | 3                     | 1     | wxy_2    |
| 45      | 1      | ^GRANT                      | 3                     | 1     | wxy_2    |
| 46      | 1      | ^REVOKE                     | 3                     | 1     | wxy_2    |
| 50      | 1      | ^SELECT.*FOR UPDATE         | 3                     | 1     | wxy_2    |
| 51      | 1      | ^SELECT.*LOCK IN SHARE MODE | 3                     | 1     | wxy_2    |
| 100     | 1      | ^SELECT                     | 2                     | 1     | wxy      |
| 200     | 1      | ^SELECT                     | 4                     | 1     | wxy_2    |
+---------+--------+-----------------------------+-----------------------+-------+----------+
30 rows in set (0.00 sec)

4. 通过 monitor 库查看后端服务器健康状态

sql 复制代码

ProxySQL Admin> SELECT * FROM monitor.mysql_server_connect_log ORDER BY time_start_us DESC LIMIT 10;
+--------------+-------+------------------+-------------------------+---------------+
| hostname     | port  | time_start_us    | connect_success_time_us | connect_error |
+--------------+-------+------------------+-------------------------+---------------+
| 172.18.3.122 | 18251 | 1777270548379729 | 571                     | NULL          |
| 172.18.4.109 | 18252 | 1777270548371076 | 953                     | NULL          |
| 172.18.3.232 | 18252 | 1777270548362346 | 854                     | NULL          |
| 172.18.3.122 | 18252 | 1777270548353708 | 462                     | NULL          |
| 172.18.4.109 | 18251 | 1777270548344983 | 1033                    | NULL          |
| 172.18.3.232 | 18251 | 1777270548336322 | 819                     | NULL          |
| 172.18.3.232 | 18252 | 1777270546381347 | 750                     | NULL          |
| 172.18.4.109 | 18252 | 1777270546372332 | 917                     | NULL          |
| 172.18.3.232 | 18251 | 1777270546363212 | 780                     | NULL          |
| 172.18.3.122 | 18252 | 1777270546354110 | 496                     | NULL          |
+--------------+-------+------------------+-------------------------+---------------+
10 rows in set (0.00 sec)

5. 测试连接与路由（业务端口 6033）

在 ProxySQL 所在机器执行：

bash 复制代码

mysql -uwxy_2 -p123456 -h127.0.0.1 -P6033

这是业务入口，所有测试都走这里。同时打开 ProxySQL 管理窗口：

bash 复制代码

mysql -u admin -padmin -h 127.0.0.1 -P6032 --prompt 'ProxySQL Admin> '

（1）读写分离

sql 复制代码

-- 写请求必须走主库（hostgroup 3）
CREATE DATABASE test_proxysql;
USE test_proxysql;
CREATE TABLE t(id INT);
INSERT INTO t VALUES (1);
UPDATE t SET id=2;
DELETE FROM t WHERE id=2;

在管理端查看流量分布：

sql 复制代码

ProxySQL Admin> SELECT hostgroup, count_star, last_seen, digest_text
    ->   FROM stats_mysql_query_digest
    ->  ORDER BY last_seen DESC;
+-----------+------------+------------+----------------------------------+
| hostgroup | count_star | last_seen  | digest_text                      |
+-----------+------------+------------+----------------------------------+
| 3         | 1          | 1777270718 | INSERT INTO t VALUES (?)         |
| 3         | 1          | 1777270718 | show tables                      |
| 3         | 1          | 1777270718 | DELETE FROM t WHERE id=?         |
| 3         | 1          | 1777270718 | UPDATE t SET id=?                |
| 3         | 1          | 1777270718 | show databases                   |
| 3         | 1          | 1777270718 | CREATE TABLE t(id INT)           |
| 4         | 1          | 1777270718 | SELECT DATABASE()                |
| 3         | 1          | 1777270718 | CREATE DATABASE test_proxysql    |
| 3         | 1          | 1777270693 | select @@version_comment limit ? |
+-----------+------------+------------+----------------------------------+
9 rows in set (0.00 sec)

读写分离 100% 正确，手动执行的所有写操作，全部 → hostgroup=3（主库）；手动执行的读操作：SELECT DATABASE() → hostgroup=4（读组）。

执行的 6 条全部查到了。
多出来的是系统自动 SQL，完全正常。
读写分离正常工作。

（2）读负载均衡

bash 复制代码

[mysql@kxvv-yz-mysqlproxy~]$mysql -uwxy_2 -p123456 -h127.0.0.1 -P6033 -e "SELECT @@server_id;"
mysql: [Warning] Using a password on the command line interface can be insecure.
+-------------+
| @@server_id |
+-------------+
|    10918252 |
+-------------+
[mysql@kxvv-yz-mysqlproxy~]$mysql -uwxy_2 -p123456 -h127.0.0.1 -P6033 -e "SELECT @@server_id;"
mysql: [Warning] Using a password on the command line interface can be insecure.
+-------------+
| @@server_id |
+-------------+
|    23218252 |
+-------------+
[mysql@kxvv-yz-mysqlproxy~]$mysql -uwxy_2 -p123456 -h127.0.0.1 -P6033 -e "SELECT @@server_id;"
mysql: [Warning] Using a password on the command line interface can be insecure.
+-------------+
| @@server_id |
+-------------+
|    10918252 |
+-------------+
[mysql@kxvv-yz-mysqlproxy~]$mysql -uwxy_2 -p123456 -h127.0.0.1 -P6033 -e "SELECT @@server_id;"
mysql: [Warning] Using a password on the command line interface can be insecure.
+-------------+
| @@server_id |
+-------------+
|    10918252 |
+-------------+
[mysql@kxvv-yz-mysqlproxy~]$mysql -uwxy_2 -p123456 -h127.0.0.1 -P6033 -e "SELECT @@server_id;"
mysql: [Warning] Using a password on the command line interface can be insecure.
+-------------+
| @@server_id |
+-------------+
|    12218252 |
+-------------+
[mysql@kxvv-yz-mysqlproxy~]$mysql -uwxy_2 -p123456 -h127.0.0.1 -P6033 -e "SELECT @@server_id;"
mysql: [Warning] Using a password on the command line interface can be insecure.
+-------------+
| @@server_id |
+-------------+
|    10918252 |
+-------------+
[mysql@kxvv-yz-mysqlproxy~]$mysql -uwxy_2 -p123456 -h127.0.0.1 -P6033 -e "SELECT @@server_id;"
mysql: [Warning] Using a password on the command line interface can be insecure.
+-------------+
| @@server_id |
+-------------+
|    12218252 |
+-------------+
[mysql@kxvv-yz-mysqlproxy~]$mysql -uwxy_2 -p123456 -h127.0.0.1 -P6033 -e "SELECT @@server_id;"
mysql: [Warning] Using a password on the command line interface can be insecure.
+-------------+
| @@server_id |
+-------------+
|    10918252 |
+-------------+
[mysql@kxvv-yz-mysqlproxy~]$mysql -uwxy_2 -p123456 -h127.0.0.1 -P6033 -e "SELECT @@server_id;"
mysql: [Warning] Using a password on the command line interface can be insecure.
+-------------+
| @@server_id |
+-------------+
|    12218252 |
+-------------+
[mysql@kxvv-yz-mysqlproxy~]$mysql -uwxy_2 -p123456 -h127.0.0.1 -P6033 -e "SELECT @@server_id;"
mysql: [Warning] Using a password on the command line interface can be insecure.
+-------------+
| @@server_id |
+-------------+
|    10918252 |
+-------------+
[mysql@kxvv-yz-mysqlproxy~]$

手动单 IP 测试，看不到轮询。即使在权重均为 1 的情况下，ProxySQL 也无法实现严格的"1-2-3-1-2-3..."轮询顺序。这并非配置错误，而是由ProxySQL内部连接处理机制决定的。具体说明参见"https://blog.csdn.net/wzy0623/article/details/160352639?#t42"。

六、扩展到 N 组主从

新增一组：分配新的唯一写组、读组（如 5、6）
插入 mysql_servers（写组 5、读组 6）
插入 mysql_replication_hostgroups（5,6）
新增业务用户、默认组 = 5
新增查询规则，路由 SELECT 到 6
加载保存配置

七、关键注意事项

HostGroup 必须全局唯一：每组写 / 读组不能与其他组重复，这是多集群隔离的基础。
监控账号统一：所有 MySQL 实例用同一个 monitor 用户，简化维护。
read_only 是自动识别核心：主从切换必须正确设置 read_only/super_read_only。
故障转移：ProxySQL 仅做自动路由切换，不执行 MySQL 主从提升。通过自定义脚本可以实现对应用透明的主从自动失败切换，实例参见"https://blog.csdn.net/wzy0623/article/details/160409298"。
版本兼容：ProxySQL 2.6.5 + MySQL 8.0.22 完全兼容，注意 MySQL 8 密码插件应配置为 mysql_native_password。