[root@localhost ~]# curl -sS https://downloads.mariadb.com/MariaDB/mariadb_repo_setup |  sudo bash -s -- --mariadb-maxscale-version="2.4"  --mariadb-server-version="mariadb-10.4"
[info] Repository file successfully written to /etc/yum.repos.d/mariadb.repo
[info] Adding trusted package signing keys...
[info] Successfully added trusted package signing keys

[root@localhost ~]# yum install -y maxscale

MariaDB [(none)]> CREATE USER 'maxscale'@'%' IDENTIFIED BY 'maxscale_pw';
Query OK, 0 rows affected (2.035 sec)
MariaDB [(none)]> GRANT SELECT ON mysql.user TO 'maxscale'@'%';
Query OK, 0 rows affected (0.036 sec)
MariaDB [(none)]> GRANT SELECT ON mysql.db TO 'maxscale'@'%';
Query OK, 0 rows affected (0.005 sec)
MariaDB [(none)]> GRANT SELECT ON mysql.tables_priv TO 'maxscale'@'%';
Query OK, 0 rows affected (0.003 sec)
MariaDB [(none)]> GRANT SELECT ON mysql.roles_mapping TO 'maxscale'@'%';
Query OK, 0 rows affected (0.002 sec)
MariaDB [(none)]> GRANT SHOW DATABASES ON *.* TO 'maxscale'@'%';
Query OK, 0 rows affected (0.001 sec)
#MariaDB versions 10.2.2 to 10.2.10 also require GRANT SELECT ON mysql.* TO
'maxscale'@'%';

[root@localhost ~]# mysql -uroot -p
Enter password: 
MariaDB [(none)]> grant all privileges on *.* to 'jdoe'@'%' IDENTIFIED BY 'my_secret_password';
Query OK, 0 rows affected (0.340 sec)
MariaDB [(none)]> 

[root@localhost ~]# vim /etc/maxscale.cnf
#...修改server1增加server2，如果你2个salve，再增加server3
[server1]
type=server
address=192.168.117.128
port=3306
protocol=MariaDBBackend
[server2]
type=server
address=192.168.117.129
port=3306
protocol=MariaDBBackend
#...省略部分内容

[root@localhost ~]# vim /etc/maxscale.cnf
#...省略部分内容
[MariaDB-Monitor]
type=monitor
module=mariadbmon
servers=server1,server2
user=monitor_user
password=my_password
monitor_interval=2000
##检查复制延迟
detect_replication_lag=true
#全部slave不可用，select查询转发至master。
detect_stale_master=true
#...省略部分内容

#创建监控账号，在master上执行
CREATE USER 'monitor_user'@'%' IDENTIFIED BY 'my_password';
GRANT REPLICATION CLIENT on *.* to 'monitor_user'@'%';
#如果配置集群自动故障转移请执行，不配置故障转移可以省略
GRANT SUPER, RELOAD on *.* to 'monitor_user'@'%';

[root@localhost ~]# vim /etc/maxscale.cnf
#[Read-Write-Service] #<--删除掉原来的默认配置组
#[Read-Only-Service]#<--删除掉原来的默认配置组
#[Read-Only-Listener]#<--删除掉原来的默认配置组
#[Read-Write-Listener]#<--删除掉原来的默认配置组
#...省略部分内容，以下为新增加的内容
[Splitter-Service]
type=service
router=readwritesplit
servers=server1,server2
user=maxscale
password=maxscale_pw
#全部slave提供select查询服务
max_slave_connections=100%
#slave超时5秒，请求转发到其他slave
max_slave_replication_lag=5
#预先设置会话变量，例如 set character_set_connection=utf8,character_set_results=utf8,character_set_client=binary
use_sql_variables_in=all
#允许root用户登录
enable_root_user=1

[Splitter-Listener]
type=listener
service=Splitter-Service
protocol=MariaDBClient
port=4006
#...省略部分内容

[root@localhost ~]# systemctl start maxscale
[root@localhost ~]# systemctl enable maxscale

[root@localhost ~]# maxctrl list services
┌──────────────────┬────────────────┬─────────────┬───────────────────┬──────────────────┐
│ Service          │ Router         │ Connections │ Total Connections │ Servers          │
├──────────────────┼────────────────┼─────────────┼───────────────────┼──────────────────┤
│ Splitter-Service │ readwritesplit │ 0           │ 0                 │ server1, server2 │
└──────────────────┴────────────────┴─────────────┴───────────────────┴──────────────────┘
[root@localhost ~]# maxctrl list servers
┌─────────┬─────────────────┬──────┬─────────────┬─────────────────┬────────┐
│ Server  │ Address         │ Port │ Connections │ State           │ GTID   │
├─────────┼─────────────────┼──────┼─────────────┼─────────────────┼────────┤
│ server1 │ 192.168.117.128 │ 3306 │ 0           │ Master, Running │ 0-1-16 │
├─────────┼─────────────────┼──────┼─────────────┼─────────────────┼────────┤
│ server2 │ 192.168.117.129 │ 3306 │ 0           │ Slave, Running  │ 0-1-16 │
└─────────┴─────────────────┴──────┴─────────────┴─────────────────┴────────┘
[root@localhost ~]# maxctrl list listeners Splitter-Service
省略输出

MariaDB [(none)]> use reptest;
Database changed
MariaDB [reptest]> create table test_maxscale(id int); 
Query OK, 0 rows affected (0.539 sec)

MariaDB [reptest]> insert into test_maxscale values(87); 
Query OK, 1 row affected (0.110 sec)

MariaDB [reptest]> select * from test_maxscale;  
+------+
| id   |
+------+
|   87 |
+------+
1 row in set (0.070 sec)

MariaDB [(none)]> use reptest;
Database changed
MariaDB [reptest]> insert into test_maxscale values(86);
Query OK, 1 row affected (0.397 sec)

MariaDB [reptest]> select * from test_maxscale; 
+------+
| id   |
+------+
|   87 |
|   86 |
+------+
2 rows in set (0.073 sec)

[root@localhost ~]# mysql -P4006 -ujdoe -pmy_secret_password -h192.168.117.129 -e "insert into reptest.test_maxscale values(100);"
[root@localhost ~]# mysql -P4006 -ujdoe -pmy_secret_password -h192.168.117.129 -e "select * from reptest.test_maxscale;"
+------+
| id   |
+------+
|   87 |
|   86 |
|  100 |
+------+
[root@localhost ~]# mysql -P3306 -ujdoe -pmy_secret_password -h192.168.117.128 -e "select * from reptest.test_maxscale;"
+------+
| id   |
+------+
|   87 |
|  100 |
+------+
[root@localhost ~]# mysql -P3306 -ujdoe -pmy_secret_password -h192.168.117.129 -e "select * from reptest.test_maxscale;"
+------+
| id   |
+------+
|   87 |
|   86 |
|  100 |
+------+