Storing Application Variables

Question

There seems to be three distinct methods of storing a variable that will be available for every request in an application:

1. Global.asax.cs

   public class MvcApplication : HttpApplication
   {
       protected void Application_Start()
       {
           Application["SiteDatabase"] = new SiteDatabase();
       }
   }
   

2. OWIN:

   public partial class Startup
   {
       public void ConfigureAuthentication(IAppBuilder Application)
       {
           Application.CreatePerOwinContext<SiteDatabase>(new SiteDatabase());
       }
   } 
   

3. Static Container

   public static class GlobalVariables
   {
       private SiteDatabase _Database;
       public SiteDatabase Database
       {
           get { return _Database ?? new SiteDatabase(); }
       }
   } 
   

What are the relative advantages of each method?

Answer 1

In order:

Global.asax.cs

• Pros: Works in all ASP.NET apps, available statically so you don't have to flow the data around the app yourself.
• Cons: Not strongly-typed. Doesn’t automatically work in distributed environment.

OWIN

• Pros: Works great in OWIN and flows across the app. Using statics is considered poor programming by some.
• Cons: Doesn't work if you're not using OWIN (e.g. Katana). Doesn’t automatically work in distributed environment.

Static Container

• Pros: Works in all ASP.NET apps, available statically. Strongly-typed means no ugly casts
• Cons: It's static :) Doesn’t automatically work in distributed environment.

Database

• Pros: Works in a distributed system
• Cons: Potentially very slow; can fail due to network issues; requires a lot more code to implement reliably. The data must also be serializable.

Cache

• Pros: Similar to database, except much faster.
• Cons: Similar to database (but much faster), plus the cache isn't generally meant for long-lived objects, though the ASP.NET cache does offer that behavior (but at that point, why use the cache).