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Appendix C. Logging Information and Recipes

C.1. Log Level Descriptions
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Table C.1, “log4j Log Level Definitions” lists the typical meanings for different log levels in log4j. Your application may interpret these levels differently, depending on your choices.
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Table C.1. log4j Log Level Definitions
log4j Level JDK Level Description
FATAL
The Application Service is likely to crash.
ERROR SEVERE
A definite problem exists.
WARN WARNING
Likely to be a problem, but may be recoverable.
INFO INFO
Low-volume detailed logging. Something of interest, but not a problem.
DEBUG FINE
Low-volume detailed logging. Information that is probably not of interest.
FINER
Medium-volume detailed logging.
TRACE FINEST
High-volume detailed logging.

Note

The more verbose logging levels are not appropriate for production systems, because of the high level of output they generate.

Example C.1. Restricting Logged Information to a Specific Log Level

        <!-- Show the evolution of the DataSource pool in the logs [inUse/Available/Max]-->
<category name="org.jboss.resource.connectionmanager.JBossManagedConnectionPool">
  <priority value="TRACE" class="org.jboss.logging.XLevel"></priority>
</category>
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