I just upgraded from Glassfish 3.1 to 3.1.1 and all logging for my app below INFO (i.e. FINE/FINER/FINEST) stopped working.  Turns out there is a bug that normally expresses itself by stopping logging working altogether.  I think another symptom is glassfish starts to ignore logging if the level for the particular logger is set to FINE or below.

Anyway – fix seems to be to run the command:

asadmin set-log-levels com.sun.enterprise.server.logging.GFFileHandler=ALL

For more info see the 3.11 Release Notes