Spnego uses java.util.Logging.
For normal production use, use the WARNING level for Java logging.
Spnego seeks to trade off informing production support developers or important messages and cluttering the log.
SEVERE SEVERE messages should not occur in normal production and indicate that action should be taken.
WARN WARN messages generally indicate a configuration change should be made or an unusual event has occurred.
FINE FINE messages are for development use. All FINE level statements are surrounded with a guard so that they are not executed unless the level is FINE.
Setting the logging level to FINE should provide more information on the source of any problems.
Many logging systems enable a logging level change to be made without restarting the application. Glassfish allows log level changes to be made from the management console. They take immediate effect.