Content delivery network cache grouping

摘要

Content delivery networks (CDNs) deliver content objects for others is disclosed. End user computers are directed to an edge server for delivery of a requested content object by a universal resource indicator (URI). When an edge server does not have a copy of the content object from the URI, information is successively passed to ancestor servers within a hierarchy until the content object is found. There can be different hierarchies designated for different URIs or times at which requests are received. Once the content object is located in the hierarchical chain, the content object is passed back down the chain to the edge server for delivery.

主权项

1. A method for retrieving content objects in a content delivery network (CDN) having a plurality of points of presence (POPs) distributed geographically by checking different parent caches for different content objects, the method comprising:
receiving a first request comprising a first universal resource identifier (URI) at a first edge server having a first cache wherein:
the first edge server is in a first POP of the plurality of POPs; andthe first URI specifies a first content object; determining that the first cache does not hold the first content object; determining a first hierarchical tree of caches based on a characteristic of the first content object, wherein:
the first hierarchical tree of caches has a plurality of levels of caches to successively check upon cache misses at previous levels;the first hierarchical tree of caches comprises a first parent cache; andthe first parent cache is in a second POP of the plurality of POPs; and retrieving the first content object from the first parent cache based on determining the first hierarchical tree of caches; receiving a second request comprising a second URI at the first edge server, wherein the second URI specifies a second content object; determining that the first cache does not hold the second content object; determining a second hierarchical tree of caches based on a characteristic of the second content object, wherein:
the second hierarchical tree of caches has a plurality of levels of caches to successively check upon cache misses at previous levels;the second hierarchical tree of caches comprises a second parent cache; andthe second parent cache is in a third POP of the plurality of POPS; and retrieving the second content object from the second parent cache based on determining the second hierarchical tree of caches.