NHibernate Transaction.Commit automatically closes Session

I have a web application that is using the absolute latest version (3.3) and is using session-by-request session management within a HttpModule, so there are no problems with multiple session conflicts. Unfortunately, I am finding that the session is getting automatically closed immediately after I perform a Transaction.Commit which I only do when I am actually performing a Create, Update or Delete. I am finding this within my NHibernate log.

I know for a fact that I am not doing it, because the only call to the ISession.Close function is being done within my HttpModule.

Yes, of course I can put code in my SessionManager to check for the IsClosed parameter and then use the OpenSession function instead of GetCurrentSession, but should this even be happening? Is there some way that I can prevent this either through my configuration or some attribute that I could set on the Session or Transaction object or is this just one of the new features that I can't find any documentation anywhere on?

Please help.

Brian

I was asked to provide some code, so here is the code for the HttpModule:

public class NhibernateModule : IHttpModule
{
    public void Dispose()
    {
    }

    public void Init(HttpApplication context)
    {
        context.BeginRequest += new EventHandler(context_BeginRequest);
        context.EndRequest += new EventHandler(context_EndRequest);
    }

    public void context_BeginRequest(Object sender, EventArgs e)
    {
        WebSessionContext.Bind(NhibernateSessionManager.GetContextSession());
    }

    public void context_EndRequest(Object sender, EventArgs e)
    {
        ISession session = WebSessionContext.Unbind(NhibernateSessionManager.SessionFactory);

        if (session != null)
        {
            if (session.Transaction != null && session.Transaction.IsActive)
            {
                session.Transaction.Rollback();
            }
            else
                session.Flush();

            session.Close();
        }
    }
}

}

Next, you will find the original code that I am using within my SessionManager:

public sealed class NhibernateSessionManager
{
    private readonly ISessionFactory sessionFactory;
    public static ISessionFactory SessionFactory
    {
        get { return Instance.sessionFactory; }
    }

    private ISessionFactory GetSessionFactory()
    {
        return sessionFactory;
    }

    public static NhibernateSessionManager Instance
    {
        get { return NestedSessionManager.sessionManager; }
    }

    public static ISession GetContextSession()
    {
        ISession session;
        if (CurrentSessionContext.HasBind(SessionFactory))
        {
            session = SessionFactory.GetCurrentSession();
        }
        else
        {
            session = SessionFactory.OpenSession();
            CurrentSessionContext.Bind(session);
        }
        return session;
    }  

    private NhibernateSessionManager()
    {
        if (sessionFactory == null)
        {
            Configuration configuration;
            configuration = new Configuration().Configure(Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "web.config"));
            log4net.Config.XmlConfigurator.ConfigureAndWatch(new FileInfo(Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "web.config")));

            //Configuration configuration = new Configuration().Configure();
            if (configuration == null)
            {
                throw new InvalidOperationException("NHibernate configuration is null.");
            }
            else
            {
                sessionFactory = configuration.BuildSessionFactory();
                if (sessionFactory == null)
                    throw new InvalidOperationException("Call to BuildSessionFactory() returned null.");
            }
        }
    }

    class NestedSessionManager
    {
        internal static readonly NhibernateSessionManager sessionManager = new NhibernateSessionManager();
    }
}

Last, here is a function that is currently causing the session to close immediately after the Transaction.Commit(). Each of the inner functions retrieve the current session and then process a Save call.

    public static Int32 AddVideo(VideoFile Video, Int32 UserID, Int16 InstID)
    {
        log.Debug("Begin AddVideo");
        Int32 FileID = 0;

        using (ISession Session = NhibernateSessionManager.GetContextSession())
        {
            using (ITransaction Transaction = Session.BeginTransaction())
            {
                Video.Created = DateTime.Now;
                Video.Modified = DateTime.Now;

                FileID = (Int32)Session.Save(Video);
                Video.FileID = FileID;

                // Need to process through all the categories and insert records into the ivxFileCategories table
                // to associate the newly created file with the chosen categories
                if (Video.CategoryAssociations != null)
                {
                    log.Info("Number of categories to be associated with the video: " + Video.CategoryAssociations.Count);
                    for (int i = 0; i < Video.CategoryAssociations.Count; i++)
                    {
                        CategoryFileAssociation Assoc = (CategoryFileAssociation)Video.CategoryAssociations[i];
                        Assoc.FileID = FileID;
                        AssociationManager.AddCategoryFileTransaction(Assoc);
                    }
                }

                // Need to add the default file access for the UserDetail that is creating the new video which will always
                // be Admin because the UserDetail creating a file should always have admin access over the file, no matter
                // what their default role is.
                AssociationManager.AddFileAccessTransaction(FileID, UserID, UserClassConstants.IVXUSERCLASS_ADMIN);

                // Need to add the institutional association based on whether the new video was created by a librarian
                // or one of the iVidix admins
                AssociationManager.AddInstitutionFileTransaction(InstID, FileID);

                Transaction.Commit();
            }
        }

        log.Debug("End AddVideo");
        return FileID;
    }