Asp.net mvc 如何减少post请求的时间（TTFB）？

我在一个网站上工作。我使用MVC5和WebAPI。 TTFB对于web api请求来说太长（6~10秒），但是mvc视图的TTFB（1~2秒）是可以接受的。 当我向同一个api发布许多请求时，只有第一个请求有问题

这是我在登录方法中的代码

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现在我将我的应用程序部署到另一台服务器上，TTFB变得更短。而且该会话经常被删除的问题也得到了解决。

现在我将我的应用程序部署到另一台服务器上，TTFB变得更短。而且该会话经常被删除的问题也得到了修复

    public HttpResponseMessage Login(LoginInfo loginInfo)
    {
        string result = JsonConvert.SerializeObject(new { status = "example" });

        //check the whether user is already login
        if (HttpContext.Current.User.Identity.IsAuthenticated
            && loginInfo.UserName == (string)HttpContext.Current.Session["user"])
        {
            result = JsonConvert.SerializeObject(new { status = (string)HttpContext.Current.Session["role"] });
            return new HttpResponseMessage { Content = new StringContent(result, Encoding.UTF8, "application/json") };
        }

        Student student = studentRepo.GetById(loginInfo.UserName);
        if (student == null)
        {
            result = JsonConvert.SerializeObject(new { status = "usr" });
        }
        else
        {
            string password;
            string salt = (string)HttpContext.Current.Session["salt"];
            if (string.IsNullOrEmpty(salt))
            {
                //the login page has expired 
                result = JsonConvert.SerializeObject(new { status = "expire" });
            }
            else
            {
                password = student.Password + salt;
                password = MD5Helper.GetMd5(password);
                if (password == loginInfo.Password)
                {
                    //login success!
                    HttpContext.Current.Session.Remove("salt");
                    FormsAuthentication.SetAuthCookie(loginInfo.UserName, false);
                    HttpContext.Current.Session.Add("user", student.StuNo);
                    HttpContext.Current.Session.Add("role", student.Role);
                    result = JsonConvert.SerializeObject(new { status = student.Role });
                }
                else
                {
                    result = JsonConvert.SerializeObject(new { status = "deny" });
                }
            }
        }
        return new HttpResponseMessage { Content = new StringContent(result, Encoding.UTF8, "application/json") };
    }