Question

I have a class Worker which sends emails periodically,I start in Global.asax.cs on App_start()

public static class Worker
{
    public static void Start()
    {
        ThreadPool.QueueUserWorkItem(o => Work());
    }

    public static void Work()
    {
        var r = new DbContext();
        var m = new MailSender(new SmtpServerConfig());
        while (true)
        {
            Thread.Sleep(600000);
            try
            {
                var d = DateTime.Now.AddMinutes(-10);
                var ns = r.Set<Notification>().Where(o => o.SendEmail && !o.IsRead && o.Date < d);

                foreach (var n in ns)
                {
                    m.SendEmailAsync("[e-mail]", n.Email, NotifyMailTitle(n) + " - forums", NotifyMailBody(n));
                    n.SendEmail = false;
                }

                r.SaveChanges();
            }
            catch (Exception ex)
            {
                ex.Raize();
            }
        }
    }
 }

So I keep this dbcontext alive for the entire lifetime of the application is this a good practice ?

Answer 1

I would wrap it in a using statement inside of Work and let the database connection pool do it’s thing:

 using (DbContext r = new DbContext())
 {
     //working
 }

NOTE: I am not 100% sure how DbContext handles the db connections, I am assuming it opens one.

It is not good practice to keep a database connection ‘alive’ for the lifetime of an application. You should use a connection when needed and close it via the API(using statement will take care of that for you). The database connection pool will actually open and close connections based on connection demands.