[logback-user] Logging from Tomcat Webapp

28 Feb 2018

      Hi,

I am trying to use logback+slf4j for logging in my Apache Tomcat webapp.
Apache Tomcat version : 9.0.2
Logback Version : 1.2.3
OS : RHEL 6.9 (Santiago)

I have placed the slf4j and logback JAR files in WEB-INF/lib folder of the webapp.

I have the following logback.xml file contents. This file is in WEB-INF/classes :

<?xml version="1.0" encoding="UTF-8"?>
<configuration debug="true">
        <property name="logdir" value="/tmp"/>
        <property name="processlogfile" value="mycomp-webapp.log"/>
        <statusListener class="ch.qos.logback.core.status.NopStatusListener" />
        <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
                <encoder>
            <!--Pattern>%date{yyyy-MM-dd'T'HH:mm:ss.SSSXXX} - [%thread] - LEVEL=%-5level - %logger{36} - %msg%n</Pattern-->
            <Pattern>%msg%n</Pattern>
        </encoder>
        <filter class="ch.qos.logback.classic.filter.ThresholdFilter">
                <level>TRACE</level>
        </filter>
        </appender>
        <appender name="PROCESS" class="ch.qos.logback.core.rolling.RollingFileAppender">
        <file>${logdir}/${processlogfile}</file>
        <rollingPolicy class="ch.qos.logback.core.rolling.SizeAndTimeBasedRollingPolicy">
            <fileNamePattern>${logdir}/${processlogfile}.%d{yyyy-MM-dd}.%i
            </fileNamePattern>
            <maxHistory>10</maxHistory>
            <maxFileSize>10MB</maxFileSize>
        </rollingPolicy>

        <encoder>
            <Pattern>%date{yyyy-MM-dd'T'HH:mm:ss.SSSXXX} - [%thread] - LEVEL=%-5level - %logger{36} - %msg%n</Pattern>
        </encoder>
        </appender>

        <logger name="com.mycomp" level="TRACE">
                <appender-ref ref="PROCESS"/>
                 <appender-ref ref="STDOUT"/>
        </logger>

        <root level="TRACE">
                <appender-ref ref="STDOUT"/>
                <appender-ref ref="PROCESS"/>
        </root>
</configuration>

The log file is created in /tmp (as defined by the configuration above), however, it is empty. And I have lots of trace messages in my webapp. I thought atleast the console appender messages should get logged to catalina.out, but that is also not the case.

At Tomcat startup, I am able to see logback framework is picking up the logback.xml file from the WEB-INF/classes folder and so on, but just no hint of any messages being logged.

Regards,
Neeraj

[logback-user] Logging from Tomcat Webapp

Neeraj Vaidya