Requests that contain a query string (e.g., Asset.txt?Data=True) can be cached differently. The different methods for caching requests that contain query strings is described below.
Cache Method | Description |
---|---|
Standard-cache |
Default. This mode will ignore the query string in the URL. It will only cache a single asset per URL, regardless of the presence of query string parameters. If there is a cache miss or an expired cache asset needs to be revalidated, then the full CDN URL, including query string parameters, will be passed to the customer origin server. |
No-cache |
This mode prevents requests containing query strings from being cached. All requests that contain a query string will be forwarded to the customer origin server. |
Unique-cache |
This mode will cache an asset for each request made with a unique URL. A unique cache asset will be created by even the slightest variation in the query string. It is recommended that you enable the query string logging feature when taking advantage of unique-cache mode. Additionally, it is highly recommended that this mode be avoided when requests will contain query strings that will result in a very low cache hit ratio. For example, information such as session ID or user name would create such a scenario. |
Query string caching configuration may only be customized for customer origin traffic. The "Standard-cache" method is always applied to CDN storage traffic.
By default, no-cache or unique-cache mode cannot be used with Token-Based Authentication. This means that if you have protected at least one folder with Token-Based Authentication, then the only cache method that will be available from the MCC is standard-cache. Likewise, if you have configured query string caching to use no-cache or unique-cache mode, then you will not be allowed to protect a folder with Token-Based Authentication.
If you would like to protect your assets using Token-Based Authentication and you have other assets that require query string caching, then a custom configuration will have to be implemented for your account. This custom configuration will disable query string caching on folders that have been protected by Token-Based Authentication. If you would like such a custom configuration, then you should contact your CDN account manager.
A custom configuration, such as the one described above, will cause the options that appear on the Query-String Caching page to be disabled.