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Using Log4j

This section explains how to configure Tomcat to use log4j rather than java.util.logging for all Tomcat’s internal logging.

The steps described in this section are needed when you want to reconfigure Tomcat to use Apache log4j for its own logging. These steps are not needed if you just want to use log4j in your own web application. — In that case, just put log4j.jar and log4j.properties into WEB-INF/lib and WEB-INF/classes of your web application.

The following steps describe configuring log4j to output Tomcat’s internal logging.

log4j.rootLogger = INFO, CATALINA

# Define all the appenders

log4j.appender.CATALINA = org.apache.log4j.DailyRollingFileAppender

log4j.appender.CATALINA.File = ${catalina.base}/logs/catalina

log4j.appender.CATALINA.Append = true

log4j.appender.CATALINA.Encoding = UTF-8

# Roll-over the log once per day

log4j.appender.CATALINA.DatePattern = ‘.’yyyy-MM-dd’.log’

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

log4j.appender.CATALINA.layout.ConversionPattern = %d [%t] %-5p %c- %m%n

 

log4j.appender.LOCALHOST = org.apache.log4j.DailyRollingFileAppender

log4j.appender.LOCALHOST.File = ${catalina.base}/logs/localhost

log4j.appender.LOCALHOST.Append = true

log4j.appender.LOCALHOST.Encoding = UTF-8

log4j.appender.LOCALHOST.DatePattern = ‘.’yyyy-MM-dd’.log’

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

log4j.appender.LOCALHOST.layout.ConversionPattern = %d [%t] %-5p %c- %m%n

 

log4j.appender.MANAGER = org.apache.log4j.DailyRollingFileAppender

log4j.appender.MANAGER.File = ${catalina.base}/logs/manager

log4j.appender.MANAGER.Append = true

log4j.appender.MANAGER.Encoding = UTF-8

log4j.appender.MANAGER.DatePattern = ‘.’yyyy-MM-dd’.log’

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

log4j.appender.MANAGER.layout.ConversionPattern = %d [%t] %-5p %c- %m%n

 

log4j.appender.HOST-MANAGER = org.apache.log4j.DailyRollingFileAppender

log4j.appender.HOST-MANAGER.File = ${catalina.base}/logs/host-manager

log4j.appender.HOST-MANAGER.Append = true

log4j.appender.HOST-MANAGER.Encoding = UTF-8

log4j.appender.HOST-MANAGER.DatePattern = ‘.’yyyy-MM-dd’.log’

log4j.appender.HOST-MANAGER.layout = org.apache.log4j.PatternLayout

log4j.appender.HOST-MANAGER.layout.ConversionPattern = %d [%t] %-5p %c- %m%n

 

log4j.appender.CONSOLE = org.apache.log4j.ConsoleAppender

log4j.appender.CONSOLE.Encoding = UTF-8

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

log4j.appender.CONSOLE.layout.ConversionPattern = %d [%t] %-5p %c- %m%n

 

# Configure which loggers log to which appenders

log4j.logger.org.apache.catalina.core.ContainerBase.[Catalina].[localhost] = INFO, LOCALHOST

log4j.logger.org.apache.catalina.core.ContainerBase.[Catalina].[localhost].[/manager] =\

 

INFO, MANAGER

log4j.logger.org.apache.catalina.core.ContainerBase.[Catalina].[localhost].[/host-manager] =\

INFO, HOST-MANAGER

This tomcat-juli.jar differs from the default one. It contains the full Apache Commons Logging implementation and thus is able to discover the presense of log4j and configure itself.

This log4j configuration mirrors the default java.util.logging setup that ships with Tomcat: both the manager and host-manager apps get an individual log file, and everything else goes to the “catalina.log” log file. Each file is rolled-over once per day.

You can (and should) be more picky about which packages to include in the logging. Tomcat defines loggers by Engine and Host names. For example, for a more detailed 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.

 

log4j.logger.org.apache.catalina.core.ContainerBase.[Catalina].[localhost]=DEBUG

log4j.logger.org.apache.catalina.core=DEBUG

log4j.logger.org.apache.catalina.session=DEBUG

 

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.

Your web applications should certainly use their own log4j configuration. This is valid with the above configuration. You would place a similar log4j.properties file in your web application’s WEB-INF/classes directory, and log4jx.y.z.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 log4j documentation for more options. This page is intended only as a bootstrapping guide.

Additional notes

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