.::: Install MySQL Router load balancer for Galera MariaDB MySQL :::.

1. Disable selinux & firewalld
[root@mysqlrouter data]# sestatus
SELinux status:                 disabled
[root@mysqlrouter data]# systemctl status firewalld
● firewalld.service - firewalld - dynamic firewall daemon
   Loaded: loaded (/usr/lib/systemd/system/firewalld.service; disabled; vendor preset: enabled)
   Active: inactive (dead)
     Docs: man:firewalld(1)
[root@mysqlrouter data]#

 
2. additional hosts
[root@mysqlrouter data]# cat /etc/hosts
127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6
10.10.10.45 mysqlrouter
10.10.10.51 mariadb01
10.10.10.52 mariadb02
[root@mysqlrouter data]#

3. install client mariadb mysql
[root@mysqlrouter data]#  yum install mariadb -y

4. Download & Install mysqlrouter
[root@mysqlrouter data]# wget https://dev.mysql.com/get/Downloads/MySQL-Router/mysql-router-community-8.0.29-1.el7.x86_64.rpm
[root@mysqlrouter data]# ls
mysql-router-community-8.0.29-1.el7.x86_64.rpm
[root@mysqlrouter data]#

[root@mysqlrouter data]# yum install mysql-router-community-8.0.29-1.el7.x86_64.rpm -y


5. Start mysqlrouter
[root@mysqlrouter data]# systemctl enable mysqlrouter
Created symlink from /etc/systemd/system/multi-user.target.wants/mysqlrouter.service to /usr/lib/systemd/system/mysqlrouter.service.
[root@mysqlrouter data]# systemctl enable mysqlrouter


6. Configuration mysqlrouter.conf

[root@mysqlrouter data]# cat /etc/mysqlrouter/mysqlrouter.conf
..........................
# Documentation is available at
#    http://dev.mysql.com/doc/mysql-router/en/

[DEFAULT]
logging_folder = /var/log/mysqlrouter
runtime_folder = /run/mysqlrouter
config_folder = /etc/mysqlrouter
plugin_folder = /usr/lib64/mysqlrouter
data_folder = /etc/mysqlrouter/data

[logger]
level = INFO
filename = mysqlrouter.log
[routing:basic_failover]
bind_address = 0.0.0.0
bind_port = 7001
mode = read-write
destinations = 10.10.10.51:3306,10.10.10.52:3306
[routing:load_balance]
bind_address = 0.0.0.0
bind_port = 7002
mode = read-only
destinations = 10.10.10.51:3306,10.10.10.52:3306
# If no plugin is configured which starts a service, keepalive
# will make sure MySQL Router will not immediately exit. It is
# safe to remove once Router is configured.
[keepalive]
interval = 60
[root@mysqlrouter data]#

7. enable profile

[root@mysqlrouter mysqlrouter]# mysqlrouter -c /etc/mysqlrouter/mysqlrouter.conf

[root@mysqlrouter data]# cat /etc/profile
# /etc/profile
export PATH=$PATH:/usr/bin/mysqlrouter
# System wide environment and startup programs, for login setup
# Functions and aliases go in /etc/bashrc

....
[root@mysqlrouter data]#

8. Login mysql cluster from mysqlrouter

[root@mysqlrouter mysqlrouter]# mysql -u root -p -h 10.10.10.45 -P 7001
Enter password:
Welcome to the MariaDB monitor.  Commands end with ; or \g.
Your MariaDB connection id is 5
Server version: 10.1.48-MariaDB MariaDB Server

Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

MariaDB [(none)]> select @@hostname;
+------------+
| @@hostname |
+------------+
| mariadb01  |
+------------+
1 row in set (0.01 sec)

MariaDB [(none)]>

9 Try stop mariadb01 stop & check again status

MariaDB [(none)]> select @@hostname;
ERROR 2013 (HY000): Lost connection to MySQL server during query
MariaDB [(none)]> select @@hostname;
ERROR 2006 (HY000): MySQL server has gone away
No connection. Trying to reconnect...
Connection id:    4
Current database: *** NONE ***

+------------+
| @@hostname |
+------------+
| mariadb02  |
+------------+
1 row in set (0.04 sec)

MariaDB [(none)]>

10. check mysqlrouter version
[root@mysqlrouter data]# mysqlrouter -V
MySQL Router  Ver 8.0.29 for Linux on x86_64 (MySQL Community - GPL)
[root@mysqlrouter data]#