Some terms and concepts used throughout this document have a special meaning when used in the context of a content delivery network like Stratus. Some examples:

  • Client - The entity on behalf of which the CDN's caching services are made available.
  • User - The consumer of the client's content through the CDN's caching services.
  • CDN - Network of servers operating as an intermediary between the user and the origin, providing a geographically distributed caching service. The CDN is responsible for delivering copies of the client's content to end users, stored in a temporary basis.
  • Origin - Also called upstream, it's the set of web servers operated by the client where content is permanently stored. The origin provides the CDN with public addresses where the content being served to users may be obtained on-demand.
  • Object - Each content item handled individually by the CDN (eg. an image file).
  • Mapping (Alias) - CDN configuration specifying a direct relation between CDN addresses and their corresponding counterparts at the origin, as well as any behavior options. The CDN relies on this configuration to know where to get objects from, when they are not already present in its caches.