The JBossAS log (as of 5.0.0.Beta4) is filled with this kind of thing:

2008-02-28 17:57:51,703 DEBUG [com.arjuna.ats.arjuna.logging.arjLogger] Periodic recovery - second pass <Thu, 28 Feb 2008 17:57:51>
2008-02-28 17:57:51,703 DEBUG [com.arjuna.ats.arjuna.logging.arjLogger] AtomicActionRecoveryModule: Second pass
2008-02-28 17:57:51,703 DEBUG [com.arjuna.ats.txoj.logging.txojLoggerI18N] [com.arjuna.ats.internal.txoj.recovery.TORecoveryModule_6] - TORecoveryModule - second pass
2008-02-28 17:57:51,703 DEBUG [com.arjuna.ats.jta.logging.loggerI18N] [com.arjuna.ats.internal.jta.recovery.info.secondpass] Local XARecoveryModule - second pass
2008-02-28 17:59:51,703 DEBUG [com.arjuna.ats.arjuna.logging.arjLogger] Periodic recovery - first pass <Thu, 28 Feb 2008 17:59:51>
2008-02-28 17:59:51,704 DEBUG [com.arjuna.ats.arjuna.logging.arjLogger] StatusModule: first pass
2008-02-28 17:59:51,704 DEBUG [com.arjuna.ats.txoj.logging.txojLoggerI18N] [com.arjuna.ats.internal.txoj.recovery.TORecoveryModule_3] - TORecoveryModule - first pass
2008-02-28 17:59:51,704 DEBUG [com.arjuna.ats.jta.logging.loggerI18N] [com.arjuna.ats.internal.jta.recovery.info.firstpass] Local XARecoveryModule - first pass

These messages ought to be at TRACE level. The first hint is that this is the only thing spamming the log after successful startup. Also on more than one occasion, folks pop into the public #jboss IRC channel asking about why their logs get spammed with these messages. An otherwise idle JBossAS instance quietly gobbles 750kb of disk space a day with these messages.