ASP.NET 4 Unleashed

Using a Sliding Cache Expiration Policy

If you need to cache a lot of data, it makes more sense to use a sliding expiration policy rather than an absolute expiration policy. When you use a sliding expiration policy, data remains in the cache as long as the data continues to be requested within a certain interval.

For example, imagine that you have been asked to rewrite the Amazon website with ASP.NET. The Amazon website displays information on billions of books. You couldn’t cache all this book information in memory. However, if you use a sliding expiration policy, you can cache the most frequently requested books automatically.

The page in Listing 29.28 illustrates how you can enable a sliding cache expiration policy. The cache duration is set ...