LXD offers a quick-to-deploy, highly-efficient environment in which we can host a fault-resistant Galera cluster. In this hands-on lab, we’ll do just that by creating and configuring an initial container, then using that as a basis for a three-node Galera cluster.
Learning Objectives
Successfully complete this lab by achieving the following learning objectives:
- Configure the Initial Cluster Containers
Create the container:
lxc launch ubuntu:18.04 galera01Access the container and run initial updates:
lxc exec galera01 -- bash apt update apt upgradeAdd the MariaDB repository:
apt-key adv --recv-keys --keyserver hkp://keyserver.ubuntu.com:80 0xF1656F24C74CD1D8 add-apt-repository 'deb [arch=amd64,ppc64el] http://ftp.utexas.edu/mariadb/repo/10.1/ubuntu bionic main' apt updateInstall MariaDB:
apt install mariadb-server -yRun
mysql_secure_installation:mysql_secure_installationUpdate the
innodb_buffer_pool_sizefor the MariaDB configuration:vim /etc/mysql/my.cnfinnodb_buffer_pool_size = 16MConfigure the firewall:
ufw enable ufw allow 3306/tcp ufw allow 4444/tcp ufw allow 4567/tcp ufw allow 4568/tcp ufw allow 4567/udp ufw statusExit the container and take a snapshot:
exit lxc snapshot galera01 initCreate the two additional containers and start them:
lxc copy galera01/init galera02 lxc copy galera01/init galera03 lxc start galera02 lxc start galera03- Configure Galera
View all containers and make note of each IP address:
lxc listOpen the
galera.cnfconfiguration in thecloud_user‘s home directory and update thewsrep_cluster_addressto list all IP addresses. Update thewsrep_node_addressandwsrep_node_namefor thegalera01node:vim galera.cnf[mysqld] binlog_format=ROW default-storage-engine=innodb innodb_autoinc_lock_mode=2 bind-address=0.0.0.0 # Galera Provider Configuration wsrep_on=ON wsrep_provider=/usr/lib/galera/libgalera_smm.so # Galera Cluster Configuration wsrep_cluster_name="galera_cluster" wsrep_cluster_address="gcomm://<IP_ADDRESS>,<IP_ADDRESS>,<IP_ADDRESS>" # Galera Synchronization Configuration wsrep_sst_method=rsync # Galera Node Configuration wsrep_node_address="<IP_ADDRESS>" wsrep_node_name="galera01"Push to the first container:
lxc file push galera.cnf galera01/etc/mysql/conf.d/galera.cnfUpdate the configuration file again, changing the
addressandnameso it works withgalera02:vim galera.cnfwsrep_node_address="<IP_ADDRESS>" wsrep_node_name="galera02"lxc file push galera.cnf galera02/etc/mysql/conf.d/galera.cnfDo the same for
galera03:vim galera.cnfwsrep_node_address="<IP_ADDRESS>" wsrep_node_name="galera03"lxc file push galera.cnf galera03/etc/mysql/conf.d/galera.cnf- Start the Cluster
Stop MySQL on all nodes:
lxc exec galera01 -- systemctl stop mysql lxc exec galera02 -- systemctl stop mysql lxc exec galera03 -- systemctl stop mysqlStart the Galera cluster:
lxc exec galera01 -- galera_new_cluster lxc exec galera02 -- systemctl start mysql lxc exec galera03 -- systemctl start mysqlTo confirm that everything is working, view the cluster size on all containers:
lxc exec galera01 -- mysql -u root -p -e "show status like 'wsrep_cluster_size'" lxc exec galera02 -- mysql -u root -p -e "show status like 'wsrep_cluster_size'" lxc exec galera03 -- mysql -u root -p -e "show status like 'wsrep_cluster_size'"
