Question

I’m trying to use the cache in an ASP.NET MVC web application to store some list data that rarely updates. I insert this data into the cache in an UpdateCache() method like this:

HttpContext.Current.Cache.Insert("MyApp-Products", products, null, DateTime.Now.AddYears(99), Cache.NoSlidingExpiration);

Then in my model I retrieve it:

public static List<string> GetProducts()
{
    var cachedProducts = HttpContext.Current.Cache["MyApp-Products"];
    if (cachedProducts == null)
    {
        UpdateCache();
        cachedProducts = HttpContext.Current.Cache["MyApp-Products"];
    }
    return ((List<string>)cachedProducts );
}

The first time I visit the page, UpdateCache() is called as expected. If I refresh, the data comes from the cache and I do not need to call UpdateCache(). However, after maybe 15 mins, I come back to the app and the cached values are gone. My understanding was that this cache was per application, not session, so I would have expected it to still be there for myself or another user.

Is there something wrong with the way I’m storing the cache? Or is there something I’m not understanding about how the Cache in ASP.NET works in a web app?

Answer 1

IF this is on a full IIS, and happens around every 15minuntes. Remember to check the Idle timeout value.

That being said, if this list “never” changes, why not store it in a static array instead.