Worked on enhancing the reliability of the MySQLInputSourceDatabaseConnector in the apache/druid repository by focusing on robustness against invalid configurations. Addressed a critical bug by expanding exception handling to cover a wide range of input scenarios, reducing the risk of runtime failures due to misconfigurations. Improved maintainability by updating unit tests to ensure comprehensive coverage of edge cases and potential exceptions. Utilized Java and Maven to implement these changes, including updates to the pom.xml for necessary dependencies. This work strengthened the diagnosability and stability of MySQL input configurations, contributing to more resilient data ingestion workflows within the project.