On 1/7/26 13:49, teemu.ollakka--- via discuss wrote:
Hi Kyle! Galera operates in such a way that every transaction is replicated to every node in the cluster and committed into storage engine before success is returned to the client. This means that when the client receives the acknowledgement, there is at least one node (the one on which the transaction was originally executed on) which has persisted the transaction. So theoretically in the scenario you described, at least one of the nodes should be able to recover all the acknowledged transactions when the cluster is restarted after full crash. The fact that an alternate timeline appears after the cluster restart suggests that all the committed transactions were not recovered by the storage engine on restart. The jepsen-galera.cnf has the following InnoDB settings: # Performance related settings innodb_autoinc_lock_mode = 2 innodb_flush_log_at_trx_commit = 0
Ah, I included these because MariaDB's Galera configuration guide recommended them. https://mariadb.com/docs/galera-cluster/galera-management/configuration/configuring-mariadb-galera-cluster#performance-related-options says that setting flush_log_at_trx_commit=0 is "a safer, recommended option with Galera Cluster". But yes, it looks like setting it to 0 is actually a fast path to data loss! Should the documentation be changed?
Yours truly, --Kyle _______________________________________________ discuss mailing list -- [email protected] To unsubscribe send an email to [email protected]
