Using log4net with ASP.NET to track Session variables - asp.net

Question

Our web app captures a user's login and stores it in a session variable, similar to Session("User_Id"). I'd like to use log4net to capture the User in the log.
I see a few references to using the MDC (Mapped Diagnostic Context) has been replaced with ThreadContext properties.
Has anyone implemented this ThreadContext approach? Any suggestions?

Answer 1

In the code...
log4net.ThreadContext.Properties["Log_User"] = userName;
in the web.config
<appender name="ADONetAppender" type="log4net.Appender.ADONetAppender">
<bufferSize value="1" />
<connectionType value="System.Data.SqlClient.SqlConnection, System.Data, Version=1.0.3300.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" />
<connectionString value="set in global.asax" />
<commandText value="INSERT INTO Log4Net ([Log_Date], [Severity],[Application],[Message], [Source], [Log_User]) VALUES (#log_date, #severity, #application, #message, #source, #currentUser)" />
<parameter>
<parameterName value="#log_date" />
<dbType value="DateTime" />
<layout type="log4net.Layout.RawTimeStampLayout" />
</parameter>
...
<parameter>
<parameterName value="#currentUser" />
<dbType value="String" />
<size value="100" />
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%property{Log_User}" />
</layout>
</parameter>
</appender>

Answer 2

I always encapsulate access to all Session variables in a class. This controls access and let's me use strong typing. I do any logging in this class. Here's an example:
public static class SessionInfo
{
private static readonly ILog log = LogManager.GetLogger(typeof(SessionInfo));
private const string AUDITOR_ID_KEY = "AuditorId";
static SessionInfo()
{
log.Info("SessionInfo created");
}
#region Generic methods to store and retrieve in session state
private static T GetSessionObject<T>(string key)
{
object obj = HttpContext.Current.Session[key];
if (obj == null)
{
return default(T);
}
return (T)obj;
}
private static void SetSessionObject<T>(string key, T value)
{
if (Equals(value, default(T)))
{
HttpContext.Current.Session.Remove(key);
}
{
HttpContext.Current.Session[key] = value;
}
}
#endregion
public static int AuditorId
{
get { return GetSessionObject<int>(AUDITOR_ID_KEY); }
set { SetSessionObject<int>(AUDITOR_ID_KEY, value); }
}
}