How to set level logging to DEBUG in Tomcat? - debugging

Question

I would like to set level logging to DEBUG in tomcat but in console nevertheless only INFO and WARN output.
Could anybody tell me what's wrong?
My C:\tomcat\logging.properties:
# Licensed to the Apache Software Foundation (ASF) under one or more
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# this work for additional DEBUGrmation regarding copyright ownership.
# The ASF licenses this file to You under the Apache License, Version 2.0
# (the "License"); you may not use this file except in compliance with
# the License. You may obtain a copy of the License at
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# http://www.apache.org/licenses/LICENSE-2.0
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# limitations under the License.
handlers = 1catalina.org.apache.juli.FileHandler, 2localhost.org.apache.juli.FileHandler, 3manager.org.apache.juli.FileHandler, 4host-manager.org.apache.juli.FileHandler, java.util.logging.ConsoleHandler
.handlers = 1catalina.org.apache.juli.FileHandler, java.util.logging.ConsoleHandler
############################################################
# Handler specific properties.
# Describes specific configuration DEBUG for Handlers.
############################################################
1catalina.org.apache.juli.FileHandler.level = DEBUG
1catalina.org.apache.juli.FileHandler.directory = ${catalina.base}/logs
1catalina.org.apache.juli.FileHandler.prefix = catalina.
2localhost.org.apache.juli.FileHandler.level = DEBUG
2localhost.org.apache.juli.FileHandler.directory = ${catalina.base}/logs
2localhost.org.apache.juli.FileHandler.prefix = localhost.
3manager.org.apache.juli.FileHandler.level = DEBUG
3manager.org.apache.juli.FileHandler.directory = ${catalina.base}/logs
3manager.org.apache.juli.FileHandler.prefix = manager.
4host-manager.org.apache.juli.FileHandler.level = DEBUG
4host-manager.org.apache.juli.FileHandler.directory = ${catalina.base}/logs
4host-manager.org.apache.juli.FileHandler.prefix = host-manager.
java.util.logging.ConsoleHandler.level = DEBUG
java.util.logging.ConsoleHandler.formatter = java.util.logging.SimpleFormatter
############################################################
# Facility specific properties.
# Provides extra control for each logger.
############################################################
org.apache.catalina.core.ContainerBase.[Catalina].[localhost].level = DEBUG
org.apache.catalina.core.ContainerBase.[Catalina].[localhost].handlers = 2localhost.org.apache.juli.FileHandler
org.apache.catalina.core.ContainerBase.[Catalina].[localhost].[/manager].level = DEBUG
org.apache.catalina.core.ContainerBase.[Catalina].[localhost].[/manager].handlers = 3manager.org.apache.juli.FileHandler
org.apache.catalina.core.ContainerBase.[Catalina].[localhost].[/host-manager].level = DEBUG
org.apache.catalina.core.ContainerBase.[Catalina].[localhost].[/host-manager].handlers = 4host-manager.org.apache.juli.FileHandler
# For example, set the com.xyz.foo logger to only log SEVERE
# messages:
#org.apache.catalina.startup.ContextConfig.level = DEBUG
#org.apache.catalina.startup.HostConfig.level = DEBUG
#org.apache.catalina.session.ManagerBase.level = DEBUG
#org.apache.catalina.core.AprLifecycleListener.level=DEBUG
Example of my log:
INFO: Deploying configuration descriptor manager.xml
08.11.2010 1:06:42 org.apache.catalina.startup.HostConfig deployWAR
INFO: Deploying web application archive spring-mvc-trial.war
08.11.2010 1:06:46 org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deploying web application directory docs
08.11.2010 1:06:46 org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deploying web application directory examples
08.11.2010 1:06:46 org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deploying web application directory ROOT
08.11.2010 1:06:46 org.apache.coyote.http11.Http11AprProtocol start
INFO: Starting Coyote HTTP/1.1 on http-8080
08.11.2010 1:06:46 org.apache.coyote.ajp.AjpAprProtocol start
INFO: Starting Coyote AJP/1.3 on ajp-8009
08.11.2010 1:06:46 org.apache.catalina.startup.Catalina start
INFO: Server startup in 3777 ms
08.11.2010 1:09:36 org.apache.coyote.http11.Http11AprProtocol pause
INFO: Pausing Coyote HTTP/1.1 on http-8080
08.11.2010 1:09:36 org.apache.coyote.ajp.AjpAprProtocol pause
INFO: Pausing Coyote AJP/1.3 on ajp-8009
08.11.2010 1:09:37 org.apache.catalina.core.StandardService stop
INFO: Stopping service Catalina
08.11.2010 1:09:37 org.apache.catalina.loader.WebappClassLoader clearReferencesJdbc
SEVERE: The web application [/spring-mvc-trial] registered the JBDC driver [com.mysql.jdbc.Driver] but failed to unregister it when the web application was stopped. To prevent a memory leak, the JDBC Driver has been forcibly unregistered.
08.11.2010 1:09:37 org.apache.catalina.loader.WebappClassLoader clearReferencesThreads
SEVERE: The web application [/spring-mvc-trial] appears to have started a thread named [MySQL Statement Cancellation Timer] but has failed to stop it. This is very likely to create a memory leak.
08.11.2010 1:09:38 org.apache.coyote.http11.Http11AprProtocol destroy
INFO: Stopping Coyote HTTP/1.1 on http-8080
08.11.2010 1:09:38 org.apache.coyote.ajp.AjpAprProtocol destroy
INFO: Stopping Coyote AJP/1.3 on ajp-8009

Answer 1

Firstly, the level name to use is FINE, not DEBUG. Let's assume for a minute that DEBUG is actually valid, as it makes the following explanation make a bit more sense...
In the Handler specific properties section, you're setting the logging level for those handlers to DEBUG. This means the handlers will handle any log messages with the DEBUG level or higher. It doesn't necessarily mean any DEBUG messages are actually getting passed to the handlers.
In the Facility specific properties section, you're setting the logging level for a few explicitly-named loggers to DEBUG. For those loggers, anything at level DEBUG or above will get passed to the handlers.
The default logging level is INFO, and apart from the loggers mentioned in the Facility specific properties section, all loggers will have that level.
If you want to see all FINE messages, add this:
.level = FINE
However, this will generate a vast quantity of log messages. It's probably more useful to set the logging level for your code:
your.package.level = FINE
See the Tomcat 6/Tomcat 7 logging documentation for more information. The example logging.properties file shown there uses FINE instead of DEBUG:
...
1catalina.org.apache.juli.FileHandler.level = FINE
...
and also gives you examples of setting additional logging levels:
# For example, set the com.xyz.foo logger to only log SEVERE
# messages:
#org.apache.catalina.startup.ContextConfig.level = FINE
#org.apache.catalina.startup.HostConfig.level = FINE
#org.apache.catalina.session.ManagerBase.level = FINE

Answer 2

JULI logging levels for Tomcat
SEVERE - Serious failures
WARNING - Potential problems
INFO - Informational messages
CONFIG - Static configuration messages
FINE - Trace messages
FINER - Detailed trace messages
FINEST - Highly detailed trace messages
You can find here more
https://documentation.progress.com/output/ua/OpenEdge_latest/index.html#page/pasoe-admin/tomcat-logging.html

Answer 3

In addition to what has already been said (DEBUG -> FINE, FINER, FINEST in JULI), in case you're running Tomcat using an IDE, say Eclipse, note that it stores the configuration on a different path than CATALINA_HOME, so you may need to add
-Djava.util.logging.config.file="C:\apache-tomcat-9.0.31\conf\logging.properties"
to explicit set your logging properties.
More on this here: Where can I view Tomcat log files in Eclipse?