Summary

Caching is a feature that allows ASP.NET applications to store frequently accessed items in memory for better responsiveness. ASP.NET provides two types of caching: output caching and application data caching. Output caching provides the ability to cache partial or full-page responses on the Web server. We discussed how to implement output caching, both declaratively and programmatically. Output caching can vary by parameters, which allows flexible caching for groups of requests for the same page. The @ OutputCache directive provides declarative caching setup and configuration. The HttpCachePolicy object provides programmatic caching setup and configuration. Next, we discussed Application data caching using the Cache API. This is a highly flexible and optimized way to store frequently accessed items. The Cache API provides a number of features that make it an excellent alternative to using the Application object, including memory management, concurrency management, and dependency-based expiration. Next, we reviewed caching in Web services. Finally, we closed with a discussion on design considerations for caching in Web farms.