container/webapps/docs/logging.xml - tomcat55 - Git at Google

 <?xml version="1.0"?>
 <!DOCTYPE document [
   <!ENTITY project SYSTEM "project.xml">
 ]>
 <document url="logging.html">

     &project;

   <properties>
     <title>Logging in Tomcat</title>
     <author>Allistair Crossley</author>
     <author email="yoavs@apache.org">Yoav Shapira</author>
   </properties>

 <body>

   <section name="Introduction">
   <p>
     Tomcat 5.5 uses
     <a href="http://jakarta.apache.org/commons/logging">Commons Logging</a>
     throughout its internal code allowing the
     developer to choose a logging configuration that suits their needs, e.g
     JDK Logging or
     <a href="http://logging.apache.org/log4j">Log4J</a>.
     Commons Logging provides Tomcat the ability to log
     hierarchially across various log levels without needing to rely on a particular
     logging implementation.
   </p>
   <p>
     An important consequence for Tomcat 5.5 is that the &lt;Logger&gt; element found in
     previous versions to create a <code>localhost_log</code> is no longer a valid nested element
     of &lt;Context&gt;. Instead, <code>stdout</code> will collect runtime exceptions and other uncaught
     exception generated by web applications. If the developer wishes to collect detailed internal
     Tomcat logging (i.e what is happening within the Tomcat engine), then they should configure
     a logging system such as JDK Logging or log4j as detailed next.
   </p>

   </section>

   <section name="log4j">
     <p>
       Tomcat 5.5 has done away with <code>localhost_log</code> which you may be familiar with
       as the runtime exception/stack trace log. These types of error are usually thrown
       by uncaught exceptions, but are still valuable to the developer. They can now be
       found in the <code>stdout</code> log.
     </p>

     <p>
       If you need to setup cross-context detailed logging from within Tomcat's code,
       then you can use a simple log4j configuration. Note that this logging van be very
       verbose depending on the log level you chose to use.  Note also that a log4j logging
       configuration is not going to produce stack trace type logging: those stack traces
       are output to <code>stdout</code> as discussed above.
     </p>

     <p>
       Follow the following steps to setup a file named tomcat.log that has internal
       Tomcat logging output to it:
     </p>

     <p>
       <ol>
         <li>Create a file called log4j.properties with the following content
             and save it into common/classes. </li>
         <li>
           <source>
             log4j.rootLogger=debug, R <br />
             log4j.appender.R=org.apache.log4j.RollingFileAppender <br />
             log4j.appender.R.File=${catalina.home}/logs/tomcat.log <br />
             log4j.appender.R.MaxFileSize=10MB <br />
             log4j.appender.R.MaxBackupIndex=10 <br />
             log4j.appender.R.layout=org.apache.log4j.PatternLayout <br />
             log4j.appender.R.layout.ConversionPattern=%p %t %c - %m%n <br />
             log4j.logger.org.apache.catalina=DEBUG, R
           </source>
 	</li>

 	<li><a href="http://logging.apache.org/log4j">Download Log4J</a>
             (v1.2 or later) and place the log4j jar in $CATALINA_HOME/common/lib.</li>

         <li><a href="http://jakarta.apache.org/site/binindex.cgi#commons-logging">
             Download Commons Logging</a> and place the commons-logging.jar
             (not commons-logging-api.jar) in $CATALINA_HOME/common/lib with
             the log4j jar.</li>

 	<li>Start Tomcat</li>
       </ol>
     </p>

     <p>
       This log4j configuration sets up a file called tomcat.log in your
       Tomcat logs folder with a maximum file size of 10MB and
       up to 10 backups.  DEBUG level is specified which will result in the
       most verbose output from Tomcat.
     </p>

     <p>
       You can (and should) be more picky about which packages to include
       in the logging. Tomcat 5.5 uses defines loggers by Engine and Host names.
       For example, for a default Catalina localhost log, add this to the
       end of the log4j.properties above. Note that there are known issues with
       using this naming convention (with square brackets) in log4j XML based
       configuration files, so we recommend you use a properties file as described
       until a future version of log4j allows this convention.

       <ul>
         <li>log4j.logger.org.apache.catalina.core.ContainerBase.[Catalina].[localhost]=DEBUG, R</li>
 	<li>log4j.logger.org.apache.catalina.core=DEBUG, R</li>
 	<li>log4j.logger.org.apache.catalina.session=DEBUG, R</li>
       </ul>

       Be warned a level of DEBUG will produce megabytes of logging and slow startup
       of Tomcat. This level should be used sparingly when debugging of internal Tomcat
       operations is required.
     </p>

     <p>
       Your web applications should certainly use their own log4j configuration.
       This is valid <i>with</i> the above configuration.  You would place a similar log4j.properties
       file in your web application's WEB-INF/classes folder, and log4j1.2.8.jar into
       WEB-INF/lib. Then specify your package level logging. This is a basic setup of log4j
       which does *not* require Commons-Logging,
       and you should consult the
       <a href="http://logging.apache.org/log4j/docs/documentation.html">log4j documentation</a>
       for more options.  This page is intended only as a bootstrapping guide.
     </p>

   </section>

   <section name="java.util.logging">
   <p>
     In order to configure JDK logging you should have JDK 1.4+. Tomcat 5.5 is intended for
     JDK 5.0, but can be run on JDK 1.4 using a compatibility package.
   </p>
   <p>
     In order to configure JDK Logging, you should find the JDK's logging.properties file. Check
     your JAVA_HOME environment setting to see which JDK Tomcat is using (or maybe JRE 5.0 as Tomcat
     can now run on a JRE from version 5.5). The file will be in <code>$JAVA_HOME/jre/lib</code>.
   </p>
   <p>
     The default logging.properties specifies a ConsoleHandler for routing logging to stdout and
     also a FileHandler. A handler's log level threshold can be set using SEVERE, CONFIG, INFO,
     WARN, FINE, FINEST or ALL. The logging.properties shipped with JDK is set to INFO. You
     can also target specific packages to collect logging from and specify a level. Here is how
     you would set debugging from Tomcat. You would need to ensure the ConsoleHandler's level is also
     set to collect this threshold, so FINEST or ALL should be set.
   </p>
   <p>
     <source>org.apache.catalina.level=FINEST</source>
   </p>

   <p>
     A limitation of JDK Logging appears to be the inability to have per-web application logging,
     as the configuration is per-VM. It is advisable to use log4j for per-web application logging
     as explained below.
   </p>

   </section>

 </body>
 </document>
	<?xml version="1.0"?>
	<!DOCTYPE document [
	<!ENTITY project SYSTEM "project.xml">
	]>
	<document url="logging.html">

	&project;

	<properties>
	<title>Logging in Tomcat</title>
	<author>Allistair Crossley</author>
	<author email="yoavs@apache.org">Yoav Shapira</author>
	</properties>

	<body>

	<section name="Introduction">
	<p>
	Tomcat 5.5 uses
	<a href="http://jakarta.apache.org/commons/logging">Commons Logging</a>
	throughout its internal code allowing the
	developer to choose a logging configuration that suits their needs, e.g
	JDK Logging or
	<a href="http://logging.apache.org/log4j">Log4J</a>.
	Commons Logging provides Tomcat the ability to log
	hierarchially across various log levels without needing to rely on a particular
	logging implementation.
	</p>
	<p>
	An important consequence for Tomcat 5.5 is that the <Logger> element found in
	previous versions to create a <code>localhost_log</code> is no longer a valid nested element
	of <Context>. Instead, <code>stdout</code> will collect runtime exceptions and other uncaught
	exception generated by web applications. If the developer wishes to collect detailed internal
	Tomcat logging (i.e what is happening within the Tomcat engine), then they should configure
	a logging system such as JDK Logging or log4j as detailed next.
	</p>

	</section>

	<section name="log4j">
	<p>
	Tomcat 5.5 has done away with <code>localhost_log</code> which you may be familiar with
	as the runtime exception/stack trace log. These types of error are usually thrown
	by uncaught exceptions, but are still valuable to the developer. They can now be
	found in the <code>stdout</code> log.
	</p>

	<p>
	If you need to setup cross-context detailed logging from within Tomcat's code,
	then you can use a simple log4j configuration. Note that this logging van be very
	verbose depending on the log level you chose to use. Note also that a log4j logging
	configuration is not going to produce stack trace type logging: those stack traces
	are output to <code>stdout</code> as discussed above.
	</p>

	<p>
	Follow the following steps to setup a file named tomcat.log that has internal
	Tomcat logging output to it:
	</p>

	<p>
	<ol>
	<li>Create a file called log4j.properties with the following content
	and save it into common/classes. </li>
	<li>
	<source>
	log4j.rootLogger=debug, R <br />
	log4j.appender.R=org.apache.log4j.RollingFileAppender <br />
	log4j.appender.R.File=${catalina.home}/logs/tomcat.log <br />
	log4j.appender.R.MaxFileSize=10MB <br />
	log4j.appender.R.MaxBackupIndex=10 <br />
	log4j.appender.R.layout=org.apache.log4j.PatternLayout <br />
	log4j.appender.R.layout.ConversionPattern=%p %t %c - %m%n <br />
	log4j.logger.org.apache.catalina=DEBUG, R
	</source>
	</li>

	<li><a href="http://logging.apache.org/log4j">Download Log4J</a>
	(v1.2 or later) and place the log4j jar in $CATALINA_HOME/common/lib.</li>

	<li><a href="http://jakarta.apache.org/site/binindex.cgi#commons-logging">
	Download Commons Logging</a> and place the commons-logging.jar
	(not commons-logging-api.jar) in $CATALINA_HOME/common/lib with
	the log4j jar.</li>

	<li>Start Tomcat</li>
	</ol>
	</p>

	<p>
	This log4j configuration sets up a file called tomcat.log in your
	Tomcat logs folder with a maximum file size of 10MB and
	up to 10 backups. DEBUG level is specified which will result in the
	most verbose output from Tomcat.
	</p>

	<p>
	You can (and should) be more picky about which packages to include
	in the logging. Tomcat 5.5 uses defines loggers by Engine and Host names.
	For example, for a default Catalina localhost log, add this to the
	end of the log4j.properties above. Note that there are known issues with
	using this naming convention (with square brackets) in log4j XML based
	configuration files, so we recommend you use a properties file as described
	until a future version of log4j allows this convention.

	<ul>
	<li>log4j.logger.org.apache.catalina.core.ContainerBase.[Catalina].[localhost]=DEBUG, R</li>
	<li>log4j.logger.org.apache.catalina.core=DEBUG, R</li>
	<li>log4j.logger.org.apache.catalina.session=DEBUG, R</li>
	</ul>

	Be warned a level of DEBUG will produce megabytes of logging and slow startup
	of Tomcat. This level should be used sparingly when debugging of internal Tomcat
	operations is required.
	</p>

	<p>
	Your web applications should certainly use their own log4j configuration.
	This is valid <i>with</i> the above configuration. You would place a similar log4j.properties
	file in your web application's WEB-INF/classes folder, and log4j1.2.8.jar into
	WEB-INF/lib. Then specify your package level logging. This is a basic setup of log4j
	which does not require Commons-Logging,
	and you should consult the
	<a href="http://logging.apache.org/log4j/docs/documentation.html">log4j documentation</a>
	for more options. This page is intended only as a bootstrapping guide.
	</p>

	</section>

	<section name="java.util.logging">
	<p>
	In order to configure JDK logging you should have JDK 1.4+. Tomcat 5.5 is intended for
	JDK 5.0, but can be run on JDK 1.4 using a compatibility package.
	</p>
	<p>
	In order to configure JDK Logging, you should find the JDK's logging.properties file. Check
	your JAVA_HOME environment setting to see which JDK Tomcat is using (or maybe JRE 5.0 as Tomcat
	can now run on a JRE from version 5.5). The file will be in <code>$JAVA_HOME/jre/lib</code>.
	</p>
	<p>
	The default logging.properties specifies a ConsoleHandler for routing logging to stdout and
	also a FileHandler. A handler's log level threshold can be set using SEVERE, CONFIG, INFO,
	WARN, FINE, FINEST or ALL. The logging.properties shipped with JDK is set to INFO. You
	can also target specific packages to collect logging from and specify a level. Here is how
	you would set debugging from Tomcat. You would need to ensure the ConsoleHandler's level is also
	set to collect this threshold, so FINEST or ALL should be set.
	</p>
	<p>
	<source>org.apache.catalina.level=FINEST</source>
	</p>

	<p>
	A limitation of JDK Logging appears to be the inability to have per-web application logging,
	as the configuration is per-VM. It is advisable to use log4j for per-web application logging
	as explained below.
	</p>

	</section>

	</body>
	</document>