Asp.Net DbContext ... Why is it called so often in my app? ... Confusion

Question

To learn Asp.Net Identity I have been using the Microsoft supplied Identity Samples template which can be downloaded via NuGet.

https://www.nuget.org/packages/Microsoft.AspNet.Identity.Samples/2.1.0-alpha1

OR in the package manager console run:

Install-Package Microsoft.AspNet.Identity.Samples -Pre

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PLEASE NOTE

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This example is different than the one shipped with Visual Studios. The one shipped with VS still uses Identity V1.0 and the package on NuGet uses V2.1. As such I haven't verified this behavior in the VS example ONLY the NuGet one.

My simple question is this, Why is the DbContext instance (ApplicationDbContext) called on every single page I load and not just pages / operations which use the DB?

For example, if I put a breakpoint on the ApplicationDbContext method and then navigate from the Index page to the Contact page, or the Contact page to the Index page, or even to a random test page I created the DBContext method is fired and runs through all of the UserManager, RoleManager, and SignInManager code.

Is this normal? It seems to be a lot of extra work for returning views unrelated to the DB...

Answer 1

Identity has a configuration option to check for cookie - if it is still valid. Not sure what is the default from the nuget you downloaded, but you can change it in App_Start\Startup.Auth.cs, look for code looking like this:

        app.UseCookieAuthentication(new CookieAuthenticationOptions
        {
            AuthenticationType = DefaultAuthenticationTypes.ApplicationCookie,
            LoginPath = new PathString("/Account/Login"),
            Provider = new CookieAuthenticationProvider
            {
                // Enables the application to validate the security stamp when the user logs in.
                // This is a security feature which is used when you change a password or add an external login to your account.  
                OnValidateIdentity = SecurityStampValidator.OnValidateIdentity<ApplicationUserManager, ApplicationUser>(
                    validateInterval: TimeSpan.FromMinutes(30),
                    regenerateIdentity: (manager, user) => user.GenerateUserIdentityAsync(manager))
            }
        });        

You need to check your validateInterval parameter and if it is very small period of time, make it like 10-15 minutes.

See here for full sample file.