Plug in custom Log4Net appender - nkot/Metrics.Log4Net GitHub Wiki

<appender name="Metrics.CSV.Timer" type="log4net.Appender.RollingFileAppender">
      <file type="log4net.Util.PatternString" value="metrics\Metrics.CSV.Timer.csv" />
      <staticLogFileName value="true" />
      <appendToFile value="false" />
      <rollingStyle value="Size" />
      <maximumFileSize value="10MB" />
      <maxSizeRollBackups value="10" />
      <layout type="log4net.Layout.PatternLayout">
        <header type="log4net.Util.PatternString" value="Metric Name; Metric Type; Date; Count; Mean; Unit; %newline" />
        <conversionPattern value="%property{MetricName};%property{MetricType};%property{Date};%property{Count};%property{Mean};%property{Unit};%newline" />
      </layout>
    </appender>

    <logger name="Metrics.CSV">
       <level value="ALL" />
    </logger>

    <logger name="Metrics.CSV.Timer" additivity="false">
      <appender-ref ref="Metrics.CSV.Timer" />
    </logger>