You'll need a log4j properties file, and you'll need to set the system property that log4j reads to find that properties file.

The properties file controls where the logged messages go, what their format is, and which messages are logged. For example, here is the file I use when debugging (note that I edit it to select what I want logged).

# log4j Properties file.

#

# Add the following to the command-line to use this file:

#

#	-Dlog4j.configuration=file:///C:\workspaces\log4j.properties

#

# Comments on useful settings:

#

#	log4j.rootLogger=DEBUG, stdout

#

#		Turns the logging on for the DEBUG level (default is WARN)

#

#	log4j.logger.sqlTxLogger=DEBUG

#

#		Dumps the sql statements that are being executed along with the transaction boundaries.

#



# Default logging is for WARN and higher

log4j.rootLogger=WARN, stdout



log4j.appender.stdout=org.apache.log4j.ConsoleAppender



#log4j.appender.stdout=org.apache.log4j.FileAppender

#log4j.appender.stdout.File=D:\\wtp_0.7_allinone\\trace.log



log4j.appender.stdout.layout=org.apache.log4j.PatternLayout

# Pattern to output the caller's file name and line number.

log4j.appender.stdout.layout.ConversionPattern=%d{ABSOLUTE}  %5p %-50.50c  - %m%n

# Get file and line numbers, but it's very expensive...

#log4j.appender.stdout.layout.ConversionPattern=%-8r  %5p (%F:%L)  - %m%n

#Default conversion pattern

#log4j.appender.stdout.layout.ConversionPattern=%r  %p %c %x - %m%n

# Another example pattern

#log4j.appender.stdout.layout.ConversionPattern=%5p  (%F:%L) - %m%n



# turn on low-level sql tracing (very verbose)

#log4j.logger.sqlTxLogger=DEBUG



#log4j.logger.com.ibm.team.internal.repository.QueryBindingCreator=DEBUG

#log4j.logger.com.ibm.team.internal.repository.RdbRepositoryDataMediator=DEBUG

To set the system property log4j.configuration, I would edit
the server.startup.bat script in the jazz/server directory,
and add to the CATALINA_OPTS envvar (see the top of the
above sample file for the syntax).