A Multi-Master Cluster of MariaDB based on synchronous replication.
Galera Cluster is a synchronous multi-master replication plug-in for InnoDB. It is very different from the regular MySQL Replication, and addresses a number of issues including write conflicts when writing on multiple masters, replication lag and slaves being out of sync with the master. Users do not have to know which server they can write to (the master) and which servers they can read from (the slaves).
ansible-playbook -i inventories/galera/test-db/hosts galera.yml -e 'first_time=true'| Variable | Default | Description |
|---|---|---|
ip |
- | private IP of the VM |
dns_domain |
- | specify the hostname of the node VM |
mariadb_version |
- | specify the version of MariaDB to be installed. |
galera_cluster_name |
10.5 | specify wsrep_cluster_name. |
first_time |
false | is the custom environment variable defined to determine if its first run to setup the cluster. |
mysql_root_password |
- | specify mariadb root password. |
innodb_buffer_pool_size |
512M | set innodb_buffer_pool_size for MariaDB. |
mariadb_repo_url |
default_link | It is repository_url, a URL to the directory where the repodata directory of a MariaDB repository is located. |
- CentOS Linux release 7.9.2009 (Core)
- Ansible 2.11.1
- MariaDB 10.5.10
- Galera 4
- First make sure other nodes are running well and follow these instructions.
- Navigate to mysql folder using
cd /var/lib/mysql/ - Create a new directory using
mkdir /fioldername - Copy the whole folder mysql using
rsync -avz . /foldername/ - Remove all the files in mysql folder using
rm -rf * - Again copy the mysql DB from backup folder to mysql folder using
cp -rpf /foldername/mysql . - Add innodb_force_recovery=1 in /etc/my.cnf.d/server.cnf file
- Add TimeoutSec variable in
/etc/systemd/system/mysql.servicefile - The above TimeoutSec variable value should be mentioned in secs
TimeoutSec=900 - Now start the service
systemctl start mariadb - You can check the status of cluster using
systemctl status mariadb - Once the cluster is up just comment innodb_force_recovery=1 in server.cnf file
- Then again restart the cluster using
systemctl restart mariadb