Why Hibernate Still Logs SQL Even When Disabled in application.yaml

Good leadership consists of doing less and being more. —Dave Ramsey

This blog post explores a troubleshooting scenario where Hibernate continued to output SQL statements in logs even after disabling it in the application.yaml file. It serves as a guide for your team to understand property setting logic in Spring Boot and Hibernate.

The Problem

The issue arose when SQL queries persisted in the logs despite setting hibernate.show_sql to false in application.yaml.

Investigation

Code Review: The investigation delved into the source code of Hibernate (hibernate-core-5.6.10.Final), specifically:

• SqlStatementLogger.java: This class defines the logStatement method responsible for logging SQL statements.
• JdbcServicesImpl.java: This class configures the SqlStatementLogger based on properties like showSQL. -
• StandardServiceRegistryImpl.java: This class accepts a configurationValues map containing Hibernate properties.

  Property Setting Flow: The code revealed the following flow for setting Hibernate properties:

• StandardServiceRegistryBuilder is created with configurationValues.
• This builder applies the settings to the internal registry.
• EntityManagerFactoryBuilderImpl uses this registry during building.
• Ultimately, the properties are set from 1 in your project.

  The Culprit

  The investigation identified MasterJpaConfiguration.java as the source of the issue. It explicitly set hibernate.show_sql to true, overriding any potential false setting from application.yaml.

Fixing the Issue

To resolve the problem, you can:

• Remove the hibernate.show_sql property from MasterJpaConfiguration.java.
• Set hibernate.show_sql to false in application.yaml if intended for global configuration.

  Tips for Future Troubleshooting

  When encountering unexpected behavior related to Hibernate properties:

• Search your project for keywords like hibernate.show_sql or use wildcards like hibernate.show_sql*.
• 
• Remember that properties set in Java code (like MasterJpaConfiguration.java) might override those from configuration files (like application.yaml). This blog post demonstrates a structured approach to troubleshooting Hibernate property settings in Spring Boot applications. By understanding the property flow and using proper search techniques, your team can effectively resolve similar issues in the future.

–HTH–