在本地运行时，没有实例化任何附加程序

Question

I have a web application which uses log4net. My web application is deployed to Azure, and works there perfectly. However when I run it locally through VS2013 (update 4), log4net doesn't instantiate the AdoNetAppender .

I checked for exception by breaking on all thrown exceptions, nothing was thrown, I activated the internal log4net debugging and nothing exceptional showed in the debug output.

I also added <trust level="Full"/> to my web.config , nothing...

I'm stumped, again, it works on Azure, but not locally. Any ideas? Thanks!

EDIT Here's my web.config (relevant lines only)

<configuration>
  <configSections>
    <section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler, log4net" />
  </configSections>
  <connectionStrings>
    <add name="DefaultConnection" connectionString="Data Source=.\SQLEXPRESS;Initial Catalog=**********;Integrated Security=SSPI" providerName="System.Data.SqlClient" />
  </connectionStrings>
  <log4net debug="true">
    <appender name="ADONetAppender" type="log4net.Appender.AdoNetAppender">
      <bufferSize value="1" />
      <connectionStringName value="DefaultConnection" />
      <commandText value="INSERT INTO Log ([StoreId],[Date],[Thread],[Level],[Logger],[Message],[Exception],[User]) VALUES (@store, @log_date, @thread, @log_level, @logger, @message, @exception, @user)" />
      <parameter>...</parameter>
      ...
    </appender>
    <appender name="DebugAppender" type="log4net.Appender.DebugAppender">
      <immediateFlush value="true" />
      <layout type="log4net.Layout.SimpleLayout" />
    </appender>
    <root>
      <level value="DEBUG" />
      <appender-ref ref="ADONetAppender" />
      <appender-ref ref="DebugAppender" />
    </root>
  </log4net>
  <appSettings>
    <add key="log4net.Internal.Debug" value="true" />
    <add key="log4net.Config" value="log4net.simple.config"/>
    <add key="log4net.Config.Watch" value="True"/>
  </appSettings>
  <system.web>
    <authentication mode="None" />
    <compilation debug="true" targetFramework="4.5.1" />
    <httpRuntime targetFramework="4.5.1" maxRequestLength="1048576" />
    <customErrors mode="Off" />
    <trust level="Full"/>
  </system.web>
</configuration>

UPDATE 2

I discovered that although log4net is configured properly, calling LogManager.GetLogger("...") returns a logger with no appenders. However if I inspect the hierarchy further I can see my AdoNetAppender in there, and also when XmlConfigurator.Configure() runs it outputs the following log4net: Adding appender named [ADONetAppender] to logger [root]. ...

So the problem boils down to (and this happens locally only, not on production) that the object returned from LogManager.GetLogger(...) doesn't contain any appenders.

SOLVED

See accepted answer below. It turns out all I was really missing was a call to XmlConfigurator.Configure() in my Application_Start method. All the other 'evidence' I provided is normal behavior, and the reason I wasn't seeing any log messages locally was a slight unintentional difference between the log table schema between my local db and the production one.

Answer 1

You can configure log4net in the Global.asax:

public class WebApiApplication : HttpApplication
{
    protected void Application_Start()
    {
        XmlConfigurator.Configure();

This works for azure and local.