Method and apparatus for content distribution network brokering and peering

• US 7,562,153 B2
• Filed: 07/09/2001
• Issued: 07/14/2009
• Est. Priority Date: 05/12/2000
• Status: Expired due to Term

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: AT&T Intellectual Property I LP (AT&T, Inc.)
• Inventors: Rabinovich, Michael, Douglis, Frederick, Biliris, Alexandros, Spatscheck, Oliver, Nelson, Cooper, Sturm, Walter, Cranor, Charles D., Sibal, Sandeep
• Primary Examiner(s): JEAN GILLES, JUDE
• Application Number:
  US09/901,317
• Publication Number:
  US 20020078233A1
• Time in Patent Office: 2,927 Days
• Field of Search: 709237-238, 709230-233, 709/204, 709/245, 709/250, 709223-229, 709/217, 709/213, 710 38- 39, 710/20, 395/200.3, 718/105, 712/27, 370/396, 370/701, 370/400, 726/11, 726/13
• US Class Current: 709/238
• CPC Class Codes: H04L 61/35 involving non-standard use of addresses for implementing network functionalities, e.g. coding subscription information within the address or functional addressing, i.e. assigning an address to a function
• CPC Class Codes: H04L 61/4511 using domain name system [DNS]
• CPC Class Codes: H04L 67/10 in which an application is distributed across nodes in the network software deployment G06F8/60; multiprogramming arrangements G06F9/46
• CPC Class Codes: H04L 67/1001 for accessing one among a plurality of replicated servers
• CPC Class Codes: H04L 67/10015 Access to distributed or replicated servers, e.g. using brokers
• CPC Class Codes: H04L 67/1008 based on parameters of servers, e.g. available memory or workload monitoring of computer activity G06F11/30
• CPC Class Codes: H04L 67/1012 based on compliance of requirements or conditions with available server resources
• CPC Class Codes: H04L 67/1014 based on the content of a request
• CPC Class Codes: H04L 67/1021 based on client or server locations
• CPC Class Codes: H04L 67/1023 based on a hash applied to IP addresses or costs
• CPC Class Codes: H04L 67/1029 using data related to the state of servers by a load balancer
• CPC Class Codes: H04L 67/1031 Controlling of the operation of servers by a load balancer, e.g. adding or removing servers that serve requests
• CPC Class Codes: H04L 67/52 specially adapted for the location of the user terminal
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

The present invention provides an architecture that advantageously leverages multiple content distribution networks to provide enhanced services. In accordance with an embodiment of the present invention, a share of content requests are served by each of a plurality of content distribution networks. The fraction of content requests served by a particular content distribution network can be determined dynamically, depending on the offered load or other traffic characteristics.

Claims

1. A method of serving content in a packet-switched network comprising:

choosing from a plurality of content distribution networks which content distribution network will respond to a content request from a client;

redirecting the client to the chosen content distribution network by rewriting a pointer embedded in a document as a rewritten pointer before serving the content to the client so that the content request will be served by the chosen content distribution network as indicated by the rewritten pointer and wherein

one of the plurality of content distribution networks is chosen only if a measured load of the one of the plurality of content distribution networks does not exceed a predetermined capacity reserved on the one of the plurality of content distribution networks.

2. The method of claim 1 wherein the content distribution network is chosen based, at least partly, on a determination of which of the plurality of content distribution networks is closer to the client.

3. The method of claim 1, wherein the pointer to the content is rewritten to point to a server in the chosen content distribution network.

4. The method of claim 1, wherein the pointer to the content is rewritten to point to a domain name served by the content distribution network.

5. The method of claim 1, wherein the pointer to the content is rewritten so that an original reference may be readily parsed from a corresponding one of the rewritten references.

6. The method of claim 1, wherein the chosen content distribution network utilizes the corresponding one of the rewritten references to obtain the embedded content if the chosen content distribution network does not have an up-to-date copy of the embedded content in a cache.

7. The method of claim 1 wherein redirecting the client to the chosen content distribution network further comprises resolving domain name system queries to content served by the chosen content distribution network.

8. The method of claim 7 further comprising answering the domain name system queries with a network address of content served by the chosen content distribution network.

9. The method of claim 7 further comprising answering the domain name system queries with a network address of a domain name system server responsible for the chosen content distribution network.

10. The method of claim 7 further comprising answering domain name system queries with a domain name of content served by the chosen content distribution network.

11. The method of claim 7 further comprising forwarding the domain name system queries to a domain name server responsible for the chosen content distribution network and which directly answers the domain name system queries.

12. The method of claim 1, wherein the content distribution network serves the content request from a local cache and wherein the content distribution network has access to a second copy of the content if there is a cache miss.

13. The method of claim 12, wherein the content distribution network includes a table of associations between references to content served by the content distribution network and references to a second copy of the content served from elsewhere in the network.

14. The method of claim 12 wherein the content distribution network transforms references to content served by the content distribution network into second references to a second copy of the content served from elsewhere in the network.

15. A system comprising:

means for choosing a content distribution network from a plurality of content distribution networks for responding to a content request from a client; and

means for redirecting the client to the chosen content distribution network by rewriting a pointer embedded in a document as a rewritten pointer before serving the content to the client so that the content request will be served by the chosen content distribution network as indicated by the rewritten pointer and wherein

the means for choosing a content distribution network from a plurality of content distribution networks for responding to a content request from a client is configured to choose a content distribution network only if a measured load of the content distribution network does not exceed a predetermined capacity reserved on the content distribution network.

16. The system of claim 15, further comprising:

means for serving content from a local cache; and

means for serving content from a second copy of the content when the means for serving content from a local cache experiences a cache miss.

17. The system of claim 16, further comprising:

means for transforming references to content served by the content distribution network into second references to the second copy of the content served from elsewhere in the network.