Galera is a synchronous multi-master cluster for MySQL/InnoDB databases. For more information about the product and its features, please visit the official webpage.
The two components Galera cluster comprised of are Galera plugin itself and a patched version of MySQL server which connect using wsrep API.
Install the AUR.AUR and AUR packages from the
Enable at startup
To enable mysql daemon to start at boot, add the mysqld service to systemd:
# systemctl enable mysqld.service
Once you have installed theAUR and AUR packages, you need to configure the cluster.
On each node edit
/etc/mysql/my.cnf and update the wsrep_cluster_address variable so it contains the list of all nodes in the cluster:
Change the variables wsrep_node_address and wsrep_node_name to the IP address/hostname and name(this doesn't need to be unique) for each node, e.g.:
The wsrep_cluster_name variable should contain the same name for all cluster nodes:
Also, set wsrep_sst_method to the desired state snapshot transfer method, the preferred one is rsync.
When you have finished with
/etc/mysql/my.cnf, start the mysqld service on the first node:
# systemctl start mysqld-bootstrap.service
This will bootstrap the cluster. Use MySQL's command line tool to log in as root into your MySQL server:
$ mysql -p -u root
Check the status of the cluster:
mysql> SHOW STATUS LIKE 'wsrep_%';
This will show you wsrep-related status variables:
... | wsrep_local_state | 4 | | wsrep_local_state_comment | Synced | | wsrep_cert_index_size | 0 | | wsrep_causal_reads | 0 | | wsrep_incoming_addresses | 192.168.1.4:3306 | | wsrep_cluster_conf_id | 1 | | wsrep_cluster_size | 1 | | wsrep_cluster_state_uuid | 6cd96745-2ea8-11e3-bbc8-d666651b51ef | | wsrep_cluster_status | Primary | | wsrep_connected | ON | | wsrep_local_index | 0 | | wsrep_provider_name | Galera | ...
If you use xtrabackup or mysqldump SST method, you will need to create a MySQL user for sst transfers.
Once you configured the first node, you should be able to start all other nodes with:
# systemctl start mysqld.service