Tomcat logs its output in a file called catalina.out. Such file contains the output from the server itself and from all the web applications that don't specify an alternative output file.
Different loggers can be used to log web application outputs. The following instructions are for java.util.logging and Log4j.
Web Application logging with java.util.logging
All you have to do is create a file called logging.properties in WEB-INF/classes with the following content, where you have replaced APPLICATION_OUTPUT_FILE with your choice of output file name (it would be nice to have in it the name of the application that produced the file):
handlers = org.apache.juli.FileHandler
############################################################
# Handler specific properties.
# Describes specific configuration info for Handlers.
############################################################
org.apache.juli.FileHandler.level = FINE
org.apache.juli.FileHandler.directory = ${catalina.base}/logs
org.apache.juli.FileHandler.prefix = APPLICATION_OUTPUT_FILE.
If you now redeploy your application all the output from your application will be logged in a file called $
-$
.log, so a file is created each day. There is no way to change this configuration as it is all done internally in tomcat.
The advantage of using java.util.logging over log4j is that no additional dependencies are introduced.
Redirection stdout and stderr to Logger
By default Tomcat will not redirect stdout and stderr to the Logger. This behaviour ca be changed by setting the context parameter swallowOutput to true. This has been done on glast-tomcat02 and glast-tomcat03.
Monitoring the log file
Use probe to monitor the log file produced by your application going to:
http://_serverName_.slac.stanford.edu:8080/probe/logs/
where serverName is the tomcat server on which the application has been deployed.