Content Delivery Network

The creoline® CDN (Content Delivery Network) enables the decentralized and location-dependent distribution of static resources such as images, JavaScript or CSS. Thanks to the anycast network used, the optimal geographical edge server can provide the static resources.


By using anycast DNS, load balancers and HA (high availability), we can guarantee a robust technology stack for the CDN. The general request lifecycle is visualized technically in the following flowchart:

Basic CDN Request Lifecycle


When a static resource is called up via the associated CDN domain, the optimum edge server is first determined on the basis of distance using the Anycast DNS network. The HTTP request is routed to the edge server.

  • Option 1: Cache available

If the static resource is already available in the Edge Server cache, the cache is immediately returned to the client.

Option 2: Cache not available

If the static resource is not yet available in the edge server cache, the HTTP request is forwarded to the underlying infrastructure. The HTTP request is handled differently depending on the MIME type and forwarded to your defined target server (origin server) and then processed by the rendering servers, e.g. to convert a WebP graphic. The processed static resource is then made available to the edge server so that the next identical HTTP request can be delivered directly from the edge server.


  • Image compression (for JPG, PNG and WebP graphics)
  • Automatic WebP conversion with fallback option
  • Rendering API](/en/doc/rendering-api-Jarp0w1DpU) (optional)

Image compression and WebP conversion can only be used for source resources up to 10 MB. If the source file on your target server is larger than 10 MB, the original file will be returned.

CDN domain

When setting up your CDN resource, you can define your own CDN domain for access to the Content Delivery Network. This consists of a freely selectable subdomain, the main domain

The following special requirements also apply to the subdomain:

  • Minimum character length: 4
  • Maximum character length: 25
  • Allowed characters: a-z, A-Z, -
  • The CDN domain has not been assigned in the last 90 days

Please note that you cannot reuse CDN domains or alias domains for at least 90 days after they have been canceled or deleted. The primary domain of a CDN resource cannot be changed after registration.