Content delivery network cache grouping

A CDN for caching content objects according to a selectable arrangement of separate caches, the CDN comprising:

• a plurality of POPs;
• a plurality of edge servers distributed among the plurality of POPs, wherein the plurality of edge servers comprise a plurality of caches;
• and
• a cache parent determining function that receives a plurality of URIs specifying a plurality of content objects for delivery to end user computers, wherein:
• the plurality of URIs include information that allows selecting from the plurality of caches that would serve as a parent cache to find the content object should a cache, previously assigned the content object, not have the content object, and
• different URIs have different parent caches
• wherein:
• the plurality of URIs include a first URI and a second URI;
• both the first URI and second URI are received at a same POP;
• the first URI has a first hierarchical tree of caches in multiple POPs;
• the second URI has a second hierarchical trees of caches in multiple POPs;
• and
• the first hierarchical tree is different from the second hierarchical tree.

A method for caching content objects according to a selectable arrangement of separate caches of a CDN, the method comprising:

• receiving a first URI at a cache of an edge server in a first POP, wherein the first URI specifies a first content object;
• determining that the cache does not hold the first content object;
• analyzing the first URI to determine a first parent cache;
• requesting the first content object from the first parent cache in a second POP;
• receiving a second URI at the cache of the edge server in the first POP, wherein the second URI specifies a second content object;
• determining that the cache does not hold the second content object;
• analyzing the second URI to determine a second parent cache different from the first parent cache, wherein the second parent cache is in the second POP;
• and
• requesting the content object from the second parent cache.

A method to cache content objects in a content delivery network (CDN) according to an arrangement of using different parent caches for different URIs, the method comprising:

• receiving a first universal resource indicator (URI) at a cache of an edge server in a first points of presence (POP), wherein the first URI specifies a first content object;
• determining that the cache does not hold the content object;
• analyzing the first URI to determine a first parent cache;
• requesting the content object from the first parent cache in a second POP;
• receiving a second URI at the cache of the edge server in the first POP, wherein the second URI specifies the content object;
• analyzing the second URI to determine a second parent cache different from the first parent cache, wherein the second parent cache is in the first POP;
• and
• requesting the content object from the second parent cache,
• wherein the first and second POPs are associated with different levels of quality of service.