Sitecore custom log file is empty

Question

Please help me what am missing in writing log for the exception. Always am getting an empty file

Logger in Sitecore.Config

<?xml version="1.0" encoding="UTF-8"?>
<log4net>
   <appender name="CustomLogFileAppender" type="log4net.Appender.SitecoreLogFileAppender, Sitecore.Logging">
      <file value="$(dataFolder)/logs/Custom/CustomLog.log" />
      <encoding value="utf-8" />
      <staticLogFileName value="false" />
      <datePattern value="_yyyyMMdd" />
      <rollingStyle value="Date" />
      <lockingModel type="log4net.Appender.FileAppender+MinimalLock" />
      <appendToFile value="true" />
      <preserveLogFileNameExtension value="true" />
      <layout type="log4net.Layout.PatternLayout">
         <conversionPattern value="%d (%-5p) %n%m%n%n" />
      </layout>
   </appender>
   <root>
      <priority value="INFO" />
      <appender-ref ref="LogFileAppender" />
   </root>
   <logger name="CustomLog" additivity="false">
      <priority value="INFO" />
      <appender-ref ref="CustomLogFileAppender" />
   </logger>
</log4net>

Code:

ILog Logger = LogManager.GetLogger("CustomLog");
try
{ }
catch(Exception e)
{
    Logger.Info(e);
}

Answer 1

Two possible problems that could cause this i can think of:

1. You are referencing log4net.dll instead of Sitecore.Logging.dll, You need to reference Sitecore.Logging.dll in your project for Sitecore custom logger to work

2. You custom log4net configurations lives outside <sitecore> node, Make sure it is located within that node:

Hope this helps

Answer 2

I think that

 <priority value="INFO" />

Should be changed to

<level value="INFO"/>

Give that a go

Answer 3

For logging exception you should never use Info method. You should use Warn, Error or Fatal and pass the exception to that method. Thanks to that, nice stack trace will be populated in the log file, e.g.:

catch(Exception e)
{
  Log.Warn("Some meaningful description", e, "CustomLog");
}

Also make sure that you use what @JKerny wrote in his answer: use level instead of priority for log level value.

Answer 4

Try it.

<sc.variable name="logLevel" set:value="INFO"/>
<log4net>
  <appender name="CustomLogFileAppender" type="log4net.Appender.SitecoreLogFileAppender, Sitecore.Logging">
    <file value="$(dataFolder)/logs/log.{date}.txt" />
    <appendToFile value="true" />
    <layout type="log4net.Layout.PatternLayout">
      <conversionPattern value="%5t %d{yyyy-MM-dd HH:mm:ss.fff} %-5p %c - %m%n" />
    </layout>
  </appender>
  <root>
    <priority set:value="$(logLevel)" />
  </root>
  <logger name="CustomLog" additivity="false">
    <level value="$(logLevel)" />
    <appender-ref ref="CustomLogFileAppender" />
  </logger>
</log4net>