Web Application and Database Redundancy

U1, U2 & U3 Configuration

Sudo adduser cameron
Sudo usermod -aG sudo cameron
Sudo hostnamectl set-hostname u1-cameron
Sudo nano /etc/netplan/00-installer-config.yaml

U1

U2

U3

Sudo netplan apply
Reboot

Galera Installion and Configuration

sudo apt update
sudo apt install mariadb-server mariadb-client galera-4 rsync -y

sudo systemctl enable mariadb
sudo systemctl start mariadb

sudo nano /etc/mysql/mariadb.conf.d/60-galera.cnf

U1

U2

U3

Firewall Rules

sudo ufw allow 3306/tcp      # MySQL/MariaDB
sudo ufw allow 4444/tcp      # Galera replication
sudo ufw allow 4567/tcp      # Galera communication
sudo ufw allow 4568/tcp      # Galera IST (incremental state transfer)
sudo ufw allow 22/tcp        # SSH
sudo ufw reload

Initialize The Cluster

On U1

sudo systemctl stop mariadb
sudo galera_new_cluster

On U2 & U3

sudo systemctl stop mariadb
sudo systemctl start mariadb

Test Cluster

Sudo mysql -u root -p 

Show status like ‘wsrep_cluser_size’;

Secure The Databases

sudo mysql_secure_installation