One of the default persistence provider's properties that you can set in the persistence.xml file is eclipselink.logging.level. For example, setting the logging level to FINE or higher logs all SQL statements. For details about this property, see Using EclipseLink JPA Extensions for Logging.
You can also set the EclipseLink logging level globally in the GlassFish Server by setting a JVM option using the asadmin create-jvm-options command. For example:
asadmin create-jvm-options -Declipselink.logging.level=FINE
Setting the logging level to OFF disables EclipseLink logging. A logging level set in the persistence.xml file takes precedence over the global logging level.