Independent researcher Jepsen has identified critical flaws in MariaDB Galera Cluster 12.1.2, revealing that the popular SQL database loses transactions in specific scenarios despite claims of "no lost transactions." The research found committed transactions can be lost during node crashes and network partitions, undermining the system's reliability claims in production environments.

Galera Cluster, an active-active replication system acquired by MariaDB in 2025, fails to satisfy its claimed isolation level between Serializable and Repeatable Read. The documentation incorrectly states transactions are committed on all nodes, while the system actually continues operating when minority nodes fail—a contradiction affecting data integrity guarantees for distributed applications.

These findings raise serious concerns for organizations relying on MariaDB Galera Cluster for critical applications. The transaction loss issues combined with documentation inaccuracies create a trust gap that requires immediate attention from users and the MariaDB development team to prevent potential data corruption.