MariaDB galera

• Bespielsetup mit keepalived (failover IP) auf zwei haproxy-Instanzen (die ein frontend + backend auf die galera-nodes aufmacht)
• https://computingforgeeks.com/how-to-setup-mariadb-galera-cluster-on-ubuntu-18-04-with-haproxy/
• limitations

Bespielplaybook der Rolle mrlesmithjr.mariadb_galera_cluster.

SHOW STATUS LIKE 'wsrep%';

Erklärung der Metriken

SHOW STATUS LIKE 'wsrep_cluster_size';
+--------------------+-------+
| Variable_name      | VALUE |
+--------------------+-------+
| wsrep_cluster_size | 3     |
+--------------------+-------+
 
SHOW STATUS LIKE 'wsrep_cluster_status';
+----------------------+---------+
| Variable_name        | VALUE   |
+----------------------+---------+
| wsrep_cluster_status | PRIMARY |
+----------------------+---------+
 
SHOW STATUS LIKE 'wsrep_local_state_comment';
+---------------------------+--------+
| Variable_name             | VALUE  |
+---------------------------+--------+
| wsrep_local_state_comment | Synced |
+---------------------------+--------+
 
SHOW STATUS LIKE 'wsrep_last_committed';
+----------------------+---------+
| Variable_name        | VALUE   |
+----------------------+---------+
| wsrep_last_committed | 7560036 |
+----------------------+---------+

https://www.symmcom.com/docs/how-tos/databases/how-to-recover-mariadb-galera-cluster-after-partial-or-full-crash

interesting files: cat /var/lib/mysql/grastate.dat

/etc/mysql/conf.d/galera.cnf → wsrep_cluster_address