Appendix C. Logging Information and Recipes

C.1. Log Level Descriptions

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.

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>