Sitefinity CMS caches scripts, styles, fonts, and media content (images, documents, videos) on the client browser. By adding a Cache-Control header to the response of the request, Sitefinity CMS instructs the browser to cache the client-side resources. As a result, the number of server requests decreases and the response size is smaller. You can configure any Sitefinity CMS pages and libraries to use both server caching and client (browser) caching of content. The expiration of content in cache is configured by setting the appropriate client cache profile for the page or library. For more information, see Administration: Configure cache profiles
In addition, you can configure CDN and proxy server support for pages or media items. For more information, see Use CDN for library storage libraries.
Using HTTP ETag with Sitefinity CMS
The HTTP ETag is a mechanism for cache validation. When present, the ETag is used by the client (for example CDN, browser) to verify whether the cached version of the content stored on the client is still valid for the server. This way, if the content has not changed, the server does not to need to return a full response every time.
Sitefinity CMS generates ETag by default, and this behavior is included as part of the client cache implementation in the product. When running in load balanced setup, Sitefintiy CMS ensures that all nodes generate the same ETag.
The ETag generation depends on whether you have the Enable Client Cache property set to true (default setting) in your Sitefintiy CMS output cache settings, and your Media Cache Profile is enabled (default setting), and configured for caching Location “Any” (default setting), “Client” or “ServerAndClient”. For more information, see Administration: Configure cache profiles.