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Logging configuration

Logging layout patterns​

The pattern of each individual line logged by log4j can be customized in the layout element of an appender. See the following example:

Log Layout Appender Example
<appender name="SERVER" class="org.apache.log4j.RollingFileAppender">
 <errorHandler class="org.apache.log4j.helpers.OnlyOnceErrorHandler"/>
 <param name="File" value="log/nevislogrend.log"/>
 <param name="Append" value="true"/>
 <param name="MaxFileSize" value="10MB"/>
 <param name="MaxBackupIndex" value="9"/>
 <layout class="org.apache.log4j.PatternLayout">
  <param name="ConversionPattern" value="%d{ISO8601} %-15.15t %-40.40c %-5.5p %X{indent}%m%n"/>
 </layout>
</appender>

The above example will prefix log lines with the following, and in that order:

  • a date/time timestamp (%d),
  • the thread name (%t),
  • the conversation ID (%X{conversationId}),
  • the trace group (%c)
  • the priority of the trace message (%p).

It will also indent traces (%X{indent}).

Important trace groups​

The following list shows the most important general trace groups, in combination with relevant debugging use cases:

  • Full trace analysis (debugging in test environment only)

    <root>
      <priority value="DEBUG"/>
      <appender-ref ref="SERVER"/>
    </root>

  • General debugging

    <category name="ch.nevis.logrend">
     <priority value="INFO"/>
    </category>

  • General debugging translation / GuiDescriptor problems

    <category name="ch.nevis.logrend.beans.LoginBean">
      <priority value="DEBUG"/>
    </category>

  • Low level debugging

    <category name="org.eclipse.jetty">
      <priority value="DEBUG"/>
    </category>
info

For all logging groups and their description, see the log4j configuration of your instance. If you need more examples, check the default configuration template here: /opt/nevislogrend/template/conf/log4j.xml