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>

• Operational analysis including overall processing duration and total memory usage (for production systems)

  <category name="jcan.Op">
   <priority value="INFO"/>
  </category>

• 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