Settings - Performance

Cache content (minutes)

Sets the default number of minutes for which the caching API and macro engine cache content.

Cache files (minutes)

Sets the number of minutes for which the system caches images and other files on the server.

The system automatically removes files from the cache if they are modified, so file caching cannot cause the website to display outdated content.

This setting also specifies the caching interval for Azure CDN, unless overwritten by the CMSAzureCDNCacheMinutes web.config key (see Reference - Web.config application keys for details).

See also: Caching files and resources

Maximum file size to cache

Limits caching of files whose size is greater than the specified number of kilobytes. Files larger than the specified value are only cached for 1 minute, regardless of the Cache files (minutes) setting.

Redirect files to disk

If enabled, the system redirects file requests for page attachments to the corresponding physical file (if the requested file is stored in the file system).

Warning: The system stores files on the file system with GUID identifiers instead of names (to avoid conflicts). If you enable the Redirect files to disk setting, files downloaded by users have names in the GUID identifier format instead of the original file name.

Client cache (minutes)

Sets the number of minutes for which clients consider cached files to be valid and up-to-date (i.e. the length of the client cache expiration time). Specifically, the setting determines how the server sets the Expires response header for file requests. Client file caching includes images other files.

The following values are possible:

• 0 – cached files are always flagged as expired, so clients revalidate files on each request. Does NOT disable client caching for files.
• More than 0 – until a cached file expires, clients load the file’s data from the cache without sending any requests to the server. Provides the best file performance, but may cause browsers to display outdated content (if cached files are modified before the expiration interval ends).

This setting only applies to dynamic files that are managed by the Xperience application. Files stored on the file system may use a different client cache expiration time. For example, physical files served by the Xperience application through the GetResource.ashx handler use the CMSPhysicalFilesCacheMinutes web.config key (the default value is one week) and directly requested files use the IIS client cache configuration.

See also: Caching files and resources

Allow client cache revalidation

If enabled, the server adds the must-revalidate directive to the Cache-control response header of file requests. Ensures that caching clients always perform revalidation when requesting expired files (most clients revalidate by default even without the must-revalidate directive).