I cannot make log4net work in my web application :(

Question

I'm trying to set up log4net but I cannot make it work. I've put this in my Web.config:

<configSections>
  <section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler, log4net" />
</configSections>

<log4net>
  <appender name="TraceAppender" type="log4net.Appender.TraceAppender">
    <layout type="log4net.Layout.PatternLayout">
      <conversionPattern value="%date [%thread] %-5level %logger [%property{NDC}] - %message%newline" />
    </layout>
  </appender>

  <appender name="RollingFileAppender" type="log4net.Appender.RollingFileAppender">
    <file value="logfile.log" />
    <appendToFile value="true" />
    <rollingStyle value="Composite" />
    <maxSizeRollBackups value="14" />
    <maximumFileSize value="15000KB" />
    <datePattern value="yyyyMMdd" />
    <layout type="log4net.Layout.PatternLayout">
      <conversionPattern value="%date [%thread] %-5level %logger [%property{NDC}] - %message%newline" />
    </layout>
  </appender>

  <root>
    <level value="DEBUG" />
    <appender-ref ref="RollingFileAppender" />
    <appender-ref ref="TraceAppender" />
  </root>
</log4net>

Then, in my code I execute:

log4net.Config.XmlConfigurator.Configure(new FileInfo(HttpContext.Current.Server.MapPath("~/Web.config")));
ILog log = LogManager.GetLogger("MainLogger");

if (log.IsDebugEnabled)
    log.Debug("lalala");

But nothing happens. I checked the "log" variable, and it contains a LogImpl object that has all the logging levels enabled. I get no error or configuration warning, I cannot see any file in the root, in the bin or anywhere.

What do I have to do to make it work?

Answer 1

Do you have this line in your AssemblyInfo.cs file?

[assembly: log4net.Config.XmlConfigurator()]

Also, you should consider the "typeof(YourClass)" approach used by Eric in his answer below. The first time I have upvoted an alternative answer to one of mine. :)

You don't have a TraceAppender defined.

You don't have a logger named "MainLogger" configured

<logger name="MainLogger">
  <level value="DEBUG"/>
  <appender-ref ref="RollingFileAppender" />
  <appender-ref ref="TraceAppender" />
</logger>

Also, have a look here

Answer 2

You will need another method to configure log4net: log4net.Config.XmlConfigurator.Configure().

Then it will read the web.config automatically.

See http://logging.apache.org/log4net/release/manual/configuration.html, under the ".config files" section.

Answer 3

Try to write:

log4net.Config.XmlConfigurator.Configure();

instead, since Web.config is the default location where Log4Net will look.

Otherwise, remove that entire line from your code and paste the following into your AssemblyInfo.cs:

[assembly: log4net.Config.XmlConfigurator()]

This will configure Log4Net at assembly level. Then in your code, just create a logger like this:

private static readonly ILog Log = LogManager.GetLogger(typeof(YourFunkyClass));