Latitude Studio uses the Apache log4j logging utility.
Liferay's primary log configuration is managed in portal-log4j.xml file, which is packed inside portal application's WEB-INF/lib/portal-impl.jar.
Liferay also provides a second configuration file, portal-log4j-ext.xml, which can be used to override settings in the main portal-log4j.xml file.
Both of these files are in standard log4j XML configuration format. Both files allow creating and modifying appenders, binding appenders to loggers, and adjusting the default log verbosity of different classes/packages.
By default, the Latitude override file specifics a log verbosity of INFO for the com.endeca and com.endeca.portal.instrumentation packages. The file does not override any of the default log verbosity settings specified for non-Endeca components packaged in portal-log4j.xml.
In addition to the console and df.log appenders, Endeca also provides a second file appender for capturing metrics logging. This appender creates a file called df-metrics.log, which is generated in the same location as df.log.
All log entries produced by classes in com.endeca.portal.instrumentation are routed to df-metrics.log—they are not printed to the console or to df.log.
By keeping performance information separate, administrators can easily distinguish server logs from performance logs, and can easily run analysis scripts on the performance logs.