Automating Hermitage tests transaction behavior between MySQL and MariaDB using open-source tool Monastery. The project simulates concurrent database operations to expose inconsistencies in isolation levels, focusing on Dirty Reads and Writes scenarios.

The test involves two transactions modifying a shoes table with LEFT and RIGHT shoe data. At different isolation levels, MariaDB shows 100% consistency in final states across all tests, while MySQL exhibits dirty reads in 40% of cases under Read Committed. This discrepancy stems from MariaDB's stricter default isolation implementation versus MySQL's more permissive SQL standard compliance.

Key findings highlight how MySQL's adherence to ambiguous SQL standards allows phantom reads in Repeatable Read mode, whereas MariaDB's Serializable isolation prevents all anomalies. The Monastery framework enables reproducible testing across database versions, with benchmarks showing MariaDB's InnoDB engine handling 2x more concurrent transactions without data corruption.

Results underscore critical differences for developers choosing between databases. While both support ACID compliance, MariaDB's isolation level implementations align more closely with real-world consistency expectations. This project provides actionable insights for database selection in high-concurrency environments.

Why does this matter? Organizations relying on transactional integrity must understand these nuances. The test framework offers a practical tool for evaluating database behaviors beyond theoretical isolation level descriptions.