For offline installation, a number of things have to be configured in the first place:
- SELinux is disabled, or set permissive mode.
- A mysql client is optional but recommended to test out the client connectivity from MaxScale server. This requires local repository to be configured correctly.
In this example, we are going to deploy our MaxScale with the following configuration:
| Monitoring user | maxscale_monitor |
| Monitoring password | Th7sdJLKp2w |
| Read/write split port | 3306 |
| Round robin port | 3307 |
| Cluster Type | MariaDB 10.4 Galera Cluster |
Installation & Configuration
1) Download the MaxScale installer from the MariaDB download page. Choose the latest GA version and CentOS 8 as the operating system. In this example, the link that we got was:
https://dlm.mariadb.com/1092012/MaxScale/2.5.1/centos/8/x86_64/maxscale-2.5.1-1.centos.8.x86_64.rpm Transfer the downloaded package into the MaxScale server.
2) Install MariaDB MaxScale using yum:
yum localinstall maxscale-2.5.1-1.centos.8.x86_64.rpm 3) Create a monitoring user that will be used by MaxScale on one of the MariaDB servers:
CREATE USER `maxscale_monitor`@`192.168.10.220` IDENTIFIED BY 'Th7sdJLKp2';
GRANT SELECT ON mysql.* TO `maxscale_monitor`@`192.168.10.220`;
GRANT SHOW DATABASES ON *.* TO `maxscale_monitor`@`192.168.10.220`; Where, 192.168.10.220 is the IP address of our MaxScale server.
4) It is unsafe to store the monitoring user password inside the MaxScale configuration file in plain text. Therefore, we have to use encryption. MaxScale provide a tool to generate encrypted secrets called maxkeys and maxpasswd. Firstly, generate a key:
$ maxkeys
Generating .secrets file in /var/lib/maxscale.5) Then, generate the encrypted value of our password “Th7sdJLKp2w”:
$ maxpasswd Th7sdJLKp2w
D91DB5813F7C815B351CCF7D7F1ED6DB 6) Now we can use the generated value above in our MaxScale configuration at /etc/maxscale.cnf:
[maxscale]
threads=auto
# Server definitions
#
# Set the address of the server to the network
# address of a MariaDB server.
#
[mariadbgalera1]
type=server
address=192.168.10.201
port=3306
protocol=MariaDBBackend
priority=1
[mariadbgalera2]
type=server
address=192.168.10.202
port=3306
protocol=MariaDBBackend
priority=2
[mariadbgalera3]
type=server
address=192.168.10.203
port=3306
protocol=MariaDBBackend
priority=3
# Monitor for the servers
#
# This will keep MaxScale aware of the state of the servers.
# MariaDB Monitor documentation:
# https://mariadb.com/kb/en/mariadb-maxscale-24-mariadb-monitor/
[MariaDB-Monitor]
type=monitor
module=galeramon
servers=mariadbgalera1,mariadbgalera2,mariadbgalera3
user=maxscale_monitor
password=D91DB5813F7C815B351CCF7D7F1ED6DB
monitor_interval=2000
available_when_donor=true
# Service definitions
#
# Service Definition for a read-only service and
# a read/write splitting service.
#
[Read-Write-Service]
type=service
router=readwritesplit
servers=mariadbgalera1,mariadbgalera2,mariadbgalera3
user=maxscale_monitor
password=D91DB5813F7C815B351CCF7D7F1ED6DB
[Round-Robin-Service]
type=service
router=readconnroute
servers=mariadbgalera1,mariadbgalera2,mariadbgalera3
user=maxscale_monitor
password=D91DB5813F7C815B351CCF7D7F1ED6DB
router_options=slave
# Listener definitions for the services
#
# These listeners represent the ports the
# services will listen on.
#
[Read-Write-Listener]
type=listener
service=Read-Write-Service
protocol=MariaDBClient
port=3306
address=0.0.0.0
[Round-Robin-Listener]
type=listener
service=Round-Robin-Service
protocol=MariaDBClient
port=3307
address=0.0.0.0 7) Start and enable the MaxScale service on boot:
systemctl start maxscale
systemctl enable maxscale Verification
We can verify if MaxScale is running correctly by using:
$ systemctl status maxscale
● maxscale.service - MariaDB MaxScale Database Proxy
Loaded: loaded (/usr/lib/systemd/system/maxscale.service; enabled; vendor preset: disabled)
Active: active (running) since Thu 2020-07-30 03:33:54 UTC; 2min 35s ago
Main PID: 5112 (maxscale)
CGroup: /system.slice/maxscale.service
└─5112 /usr/bin/maxscale
Jul 30 03:33:54 mxb1.local maxscale[5112]: [MariaDBAuth] [Round-Robin-Service] Loaded 13 MySQL users for listener 'Round-Robin-Listener' from server 'mariadbgalera1' with c... 0x92ff8486.
Jul 30 03:33:54 mxb1.local maxscale[5112]: Listening for connections at [0.0.0.0]:3307
Jul 30 03:33:54 mxb1.local maxscale[5112]: Service 'Round-Robin-Service' started (2/3)
Jul 30 03:33:54 mxb1.local maxscale[5112]: Removing stale journal file for monitor 'MariaDB-Monitor'.
Jul 30 03:33:54 mxb1.local systemd[1]: Started MariaDB MaxScale Database Proxy.
Jul 30 03:33:54 mxb1.local maxscale[5112]: Server changed state: mariadbgalera1[192.168.10.201:3306]: new_slave. [Running] -> [Slave, Synced, Running]
Jul 30 03:33:54 mxb1.local maxscale[5112]: Server changed state: mariadbgalera2[192.168.10.202:3306]: new_slave. [Running] -> [Slave, Synced, Running]
Jul 30 03:33:54 mxb1.local maxscale[5112]: Server changed state: mariadbgalera3[192.168.10.203:3306]: new_master. [Running] -> [Master, Synced, Running] Or,
$ netstat -tulpn | grep maxscale
tcp 0 0 0.0.0.0:3306 0.0.0.0:* LISTEN 5112/maxscale
tcp 0 0 0.0.0.0:3307 0.0.0.0:* LISTEN 5112/maxscale
tcp 0 0 127.0.0.1:8989 0.0.0.0:* LISTEN 5112/maxscale Take note at the ports that are configured for MaxScale and make sure they are listening correctly.
Furthermore, you can observe the MaxScale log at
/var/log/maxscale/maxscale.log.
