Installing MaxScale¶

$ curl -LsS https://downloads.mariadb.com/MariaDB/mariadb_repo_setup | sudo bash
[info] Checking for script prerequisites.
[info] Repository file successfully written to /etc/apt/sources.list.d/mariadb.list
[info] Adding trusted package signing keys...
[info] Running apt-get update...
[info] Done adding trusted package signing keys

$ sudo apt install maxscale
$ maxscale --version
MaxScale 6.1.1

Creating a user account for MaxScale

Create a special user account for checks that incoming clients are valid. Executing the following SQL commands on the master server of your database cluster.

CREATE USER 'maxscale'@'10.10.10.%' IDENTIFIED BY 'maxscale_s3cret';
GRANT SELECT ON mysql.user TO 'maxscale'@'10.10.10.%';
GRANT SELECT ON mysql.db TO 'maxscale'@'10.10.10.%';
GRANT SELECT ON mysql.tables_priv TO 'maxscale'@'10.10.10.%';
GRANT SELECT ON mysql.columns_priv TO 'maxscale'@'10.10.10.%';
GRANT SELECT ON mysql.proxies_priv TO 'maxscale'@'10.10.10.%';
GRANT SELECT ON mysql.roles_mapping TO 'maxscale'@'10.10.10.%';
GRANT SHOW DATABASES ON *.* TO 'maxscale'@'10.10.10.%';
FLUSH PRIVILEGES;

Creating client user accounts

Creating the configuration file

Configuring the servers

Configuring the monitor

CREATE USER 'maxscale_monitor'@'10.10.10.%' IDENTIFIED BY 'maxscale_mon_s3cret';
GRANT REPLICATION CLIENT on *.* to 'maxscale_monitor'@'10.10.10.%';
FLUSH PRIVILEGES;

Configuring the services and listeners

The user and password parameters define the credentials the service uses to populate user authentication data.

mysql.procs_priv

warning: Using old user account query due to insufficient privileges. To avoid this warning, give the service user of ‘Read-Only-Service’ access to the ‘mysql.procs_priv’-table.

GRANT SELECT ON mysql.proxies_priv TO 'maxscale'@'maxscalehost';

Starting MaxScale

# start service
sudo service maxscale start

# view service status
sudo journalctl -u maxscale.service -n200 -f 

Checking MaxScale status with MaxCtrl

ubuntu@maxscale:~$ sudo maxctrl list servers
┌─────────┬──────────────┬──────┬─────────────┬─────────────────────────────┬──────┐
│ Server  │ Address      │ Port │ Connections │ State                       │ GTID │
├─────────┼──────────────┼──────┼─────────────┼─────────────────────────────┼──────┤
│ primary │ 10.10.10.40  │ 3306 │ 0           │ Master, Auth Error, Running │      │
├─────────┼──────────────┼──────┼─────────────┼─────────────────────────────┼──────┤
│ repl01  │ 10.10.10.212 │ 3306 │ 0           │ Auth Error, Running         │      │
└─────────┴──────────────┴──────┴─────────────┴─────────────────────────────┴──────┘

Fixed Auth Error

` maxscale[522]: Error during monitor permissions test for server ‘primary’: Query ‘SHOW SLAVE STATUS;’ failed: ‘Access denied; you need (at least one of) the SUPER, SLAVE MONITOR privilege(s) for this operation’.`

GRANT SLAVE MONITOR ON *.* TO 'maxscale_monitor'@'10.10.10.%';
FLUSH PRIVILEGES;

Show servers status:

ubuntu@maxscale:~$ sudo maxctrl list servers
┌─────────┬──────────────┬──────┬─────────────┬─────────────────┬─────────────────┐
│ Server  │ Address      │ Port │ Connections │ State           │ GTID            │
├─────────┼──────────────┼──────┼─────────────┼─────────────────┼─────────────────┤
│ primary │ 10.10.10.40  │ 3306 │ 3           │ Master, Running │ 0-22040-9936180 │
├─────────┼──────────────┼──────┼─────────────┼─────────────────┼─────────────────┤
│ repl01  │ 10.10.10.212 │ 3306 │ 3           │ Slave, Running  │ 0-22040-9936179 │
└─────────┴──────────────┴──────┴─────────────┴─────────────────┴─────────────────┘

Change user password

ALTER USER 'maxscale_monitor'@'10.10.10.%' IDENTIFIED BY 'maxscale_mon_s3cret';
FLUSH PRIVILEGES;