Shared content delivery infrastructure with rendezvous based on load balancing and network conditions

• US 8,291,046 B2
• Filed: 05/30/2007
• Issued: 10/16/2012
• Est. Priority Date: 02/10/1998
• Status: Expired due to Term

• Current Assignee: Sandpiper CDN, LLC (Theseus LF Asset Holdings, LLC)
• Original Assignee: Level 3 Communications LLC (Lumen Technologies, Inc.)
• Inventors: Farber, David A., Greer, Richard E., Balter, James A., Swart, Andrew D.
• Primary Examiner(s): BLAIR, DOUGLAS B
• Application Number:
  US11/806,154
• Publication Number:
  US 20070233706A1
• Time in Patent Office: 1,966 Days
• Field of Search: 709/219, 709/225, 709/226
• US Class Current: 709/219
• CPC Class Codes: G06F 16/957 Browsing optimisation, e.g. caching or content distillation
• CPC Class Codes: G06F 2209/509 Offload
• CPC Class Codes: G06F 9/505 considering the load
• CPC Class Codes: H04L 43/065 related to network devices
• CPC Class Codes: H04L 43/0817 by checking functioning
• CPC Class Codes: H04L 43/16 Threshold monitoring
• CPC Class Codes: H04L 61/30 Managing network names, e.g. use of aliases or nicknames name-to-address mapping H04L61/45
• CPC Class Codes: H04L 61/301 Name conversion
• CPC Class Codes: H04L 61/4511 using domain name system [DNS]
• CPC Class Codes: H04L 67/02 based on web technology, e.g. hypertext transfer protocol [HTTP]
• 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 67/1006 with static server selection, e.g. the same server being selected for a specific client
• 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 67/101 based on network conditions
• 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 67/1019 Random or heuristic server selection
• 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 67/1025 : Dynamic adaptation of the criteria on which the server selection is based
• CPC Class Codes: H04L 67/1036 : Load balancing of requests to servers for services different from user content provisioning, e.g. load balancing across domain name servers
• CPC Class Codes: H04L 67/1095 : Replication or mirroring of data, e.g. scheduling or transport for data synchronisation between network nodes
• CPC Class Codes: H04L 67/125 : involving control of end-device applications over a network
• CPC Class Codes: H04L 67/2895 : Intermediate processing functionally located close to the data provider application, e.g. reverse proxies
• CPC Class Codes: H04L 67/56 : Provisioning of proxy services store-and-forward switching systems in data switching networks H04L12/54
• CPC Class Codes: H04L 67/561 : Adding application-functional data or data for application control, e.g. adding metadata
• CPC Class Codes: H04L 67/563 : Data redirection of data network streams
• CPC Class Codes: H04L 67/564 : Enhancement of application control based on intercepted application data
• CPC Class Codes: H04L 67/568 : Storing data temporarily at an intermediate stage, e.g. caching
• CPC Class Codes: H04L 67/5682 : Policies or rules for updating, deleting or replacing the stored data
• CPC Class Codes: H04L 67/61 : taking into account QoS or priority requirements
• CPC Class Codes: H04L 9/40 : Network security protocols

Abstract

A method of processing requests for resources in a system in which a plurality of content providers provide multiple resources. Content providers offload the serving of some of their resources to a shared content delivery network (CDN) formed by a plurality of servers. The CDN is shared among the content providers. Some of a content provider'"'"'s content may be served from an origin server associated with that content provider, while requests for other content from that content provider are served from the shared CDN. Requests for content are directed to servers in the CDN based on load conditions on the CDN servers and network conditions.

Claims

1. A method of processing requests for resources in a system in which a plurality of content providers provide multiple resources, the method comprising:

(A) responsive to a first request from a first client for a first resource, said first resource being associated with a first content provider, said first content provider being a subscriber to a shared content delivery network (CDN) including a plurality of repeater servers, each of the repeater servers being configured to serve resources on behalf of subscribers to the CDN, said first request including at least a first name identifying said first content provider,

(a1) serving said first resource to the first client from a first repeater server in the shared CDN, said first repeater server having been selected based at least in part on (i) load on said repeater servers in said CDN, and (ii) a location corresponding to said first client; and

(a2) when the first repeater server does not have the first resource, the first repeater uses at least a first table on the first repeater server and information included with the first request for the first resource to determine a first origin server associated with the first resource, said first repeater server requesting a copy of the first resource from the first origin server, and

(B) responsive to a second request from a second client for a second resource, said second resource being associated with a second content provider distinct from said first content provider, said second content provider being a subscriber to the shared CDN, and said second request including at least a second name distinct from said first name, said second name identifying said second content provider,

(b1) serving said second resource to the second client from a second repeater server in the shared CDN, said second repeater server having been selected based at least in part on (i) load on said repeater servers in said CDN, and (ii) a location corresponding to said second client; and

(b2) when the second repeater server does not have the second resource, the second repeater uses at least a second table on the second repeater server and information included with the second request for the second resource to determine a second origin server associated with the second resource, said second repeater server requesting a copy of the second resource from the second origin server.

2. A method as in claim 1 wherein said first repeater server was selected based at least in part on data corresponding to a cost of transmission between the first repeater server and the first client, and wherein the second repeater server was selected based at least in part on data corresponding to a cost of transmission between the second repeater server and the second client.

3. A method as in claim 1 wherein the first origin server is associated with the first content provider and the second origin server is associated with the second content provider, and wherein the first resource is a first embedded object referenced in a first web page associated with the first content provider, said first web page having been served to the first client from the first origin server, and wherein the second resource is a second embedded object referenced in a second web page associated with the second content provider, said second web page having been served to the second client from the second origin server.

4. A method as in claim 1 wherein the first origin server is associated with the first content provider and the second origin server is associated with the second content provider, and wherein

said first resource is served to the first client from the shared CDN instead of from the first origin server;

and

said second resource is served to the second client from the shared CDN instead of from the second origin server, said second origin server being distinct from said first origin server.

5. A method as in claim 1 further comprising:

providing said shared CDN.

6. A method as in claim 1 wherein the first content provider is associated with a first domain and the second content provider is associated with a second domain, distinct from the first domain.

7. A method as in claim 1 wherein the first repeater server requests a copy of the first resource from a peer repeater server in the shared CDN.

8. A method as in claim 7 wherein:

the first repeater server obtains the first resource from the peer repeater server in the shared CDN or from the origin server associated with the first resource.

9. A method as in claim 1 wherein the origin server associated with the first resource is associated with the first content provider.

10. A method as in any one of claims 1-6 and 7-8 wherein the system comprises the Internet, and wherein the first request is based at least in part on a first Uniform Resource Locator (URL) that includes said first name, and wherein the second request is based, at least in part, on a second URL that includes said second name.

11. A method as in claim 10 wherein

the first resource is a resource selected from the group comprising static and dynamic:

video content, audio content, text, image content, web pages, HTML files, XML files, files in a markup language, documents, hypertext documents, data files, and embedded resources; and

the second resource is a resource selected from the group comprising static and dynamic;

video content, audio content, text, image content, web pages, HTML files, XML files, files in a markup language, documents, hypertext documents, data files, and embedded resources.

12. A method as recited in claim 1, wherein the CDN comprises at least a first repeater selector mechanism and a second repeater selector mechanism, the method further comprising:

by the first repeater selector mechanism, selecting the first repeater server to serve the first resource to the first client; and

by the second repeater selector mechanism, selecting the second repeater server to serve the second resource to the second client.

13. A method as recited in claim 12, wherein:

the step of selecting by the first repeater selector mechanism comprises a step for determining a Group Reduction Table and a Link Cost Table;

wherein said Group Reduction Table and said Link Cost Table are operable for use in selecting the first repeater server to serve the first resource to the first client and a step for redirecting the first client to the first repeater server.

14. A method as recited in claim 1, wherein the first request comprises an HTTP Request and the first name is contained in an HTTP header associated with the first request, and wherein the second request comprises an HTTP Request and the second name is contained in an HTTP header associated with the second request.

15. A method as recited in claim 14, wherein:

the first repeater server uses at least the first name and the first table on the first repeater server to identify the first origin server as an origin server from which to retrieve the first resource; and

the second repeater server uses at least the second name and the table on the second repeater server to identify the second origin server as an origin server from which to retrieve the second resource.

16. A method as recited in claim 15, wherein the first name comprises a first hostname associated with the first content provider and the second name comprises a second hostname associated with the second content provider.

17. A method as recited in claim 1, wherein each of the plurality of repeater servers is configured to record activity related to serving resources therefrom on behalf of subscribers to the CDN, the method further comprising:

responsive to the act of serving (a1), the first repeater recording at least information related to the serving of at least the first resource on behalf of the first content provider; and

responsive to the act of serving (b1), the second repeater recording at least information related to the serving of at least the second resource on behalf of the second content provider.

18. A method as recited in claim 17, wherein the information recorded by the first repeater server related to the serving of at least the first resource comprises a first timestamp associated with serving the first resource in response to the first request, and wherein the information recorded by the second repeater server related to the serving of at least the second resource comprises a second timestamp associated with serving the second resource in response to the second request.

19. A method as recited in claim 18, further comprising:

collecting first information related to the serving of at least the first resource by at least some repeater servers in the shared CDN that have served the first resource during a first given period in time, the first given period in time including a first time specified in the first timestamp, said first information being derived at least in part from the recorded information related to the serving of at least the first resource in response to the first request; and

collecting second information related to the serving of at least the second resource by at least some repeater servers in the shared CDN that have served the second resource during a second given period in time, the second given period in time including a second time specified in the second timestamp, said second information being derived at least in part from the recorded information related to the serving of at least the second resource in response to the second request.

20. A method as recited in claim 1, wherein the first origin server is located in a network operated by the first content provider distinct from the shared CDN and wherein the second origin server is located in a network operated by the second content provider distinct from the first content provider network and the shared CDN.

21. A method of processing resource requests in a computer network, the method comprising:

(A) providing a shared content delivery network including a plurality of repeater servers, wherein each of the plurality of repeater servers is configured to serve resources on behalf of a plurality of subscribers to the shared content delivery network;

(B) responsive to a first request from a first client for a first resource, said first resource being associated with a first content provider, said first content provider being a subscriber to the shared content delivery network, at a first repeater server in the shared content delivery network, said first repeater server having been selected based at least in part on (i) load on said repeater servers in said shared content delivery network, and (ii) a location corresponding to said first client;

(b1) if said first repeater server does not have said first resource, the first repeater uses at least a first table on the first repeater server and information included with the first request to determine a first origin server associated with the first resource, and said first repeater server obtaining a copy of said first resource from the first origin server; and

(b2) said first repeater server serving said first resource; and

(C) responsive to a second request from a second client, the second request being for a second resource distinct from said first resource, and said second resource being associated with a second content provider distinct from said first content provider, said second content provider being a subscriber to the content delivery network, at a second repeater server in the shared content delivery network, said second repeater server having been selected based at least in part on (i) load on said repeater servers in said shared content delivery network, and (ii) a location corresponding to said second client;

(c1) if said second repeater server does not have said second resource, the second repeater uses at least a second table on the second repeater server and information included with the second request to determine a second origin server associated with the second resource, and said second repeater server obtaining a copy of said second resource from said second origin server; and

(c2) said second repeater server serving said second resource.

22. A method as in claim 21 wherein said first repeater server was selected based at least in part on data corresponding to a cost of transmission between the first repeater server and the first client, and wherein the second repeater server was selected based at least in part on data corresponding to a cost of transmission between the second repeater server and the second client.

23. A method as in any one of claims 21-22 wherein the computer network comprises the Internet, and wherein the first request is based at least in part on a first Uniform Resource Locator (URL) that includes a first hostname, and wherein the second request is based, at least in part, on a second URL that includes a second hostname.

24. A method as in claim 23 wherein

the first resource and the second resource are selected from the group comprising static and dynamic:

video content, audio content, text, image content, web pages, HTML files, XML files, files in a markup language, documents, hypertext documents, data files, and embedded resources.

25. A method as in claim 21 wherein:

said first request is an HTTP request.

26. A method as in claim 25 wherein said HTTP request is directed to said first repeater server by an HTTP REDIRECT command.

27. A method as recited in claim 21, further comprising:

providing a first repeater selector mechanism associated with the first content provider and a second repeater selector mechanism associated with the second content provider; and

by the first repeater selector mechanism, selecting the first repeater server to serve the first resource to the client; and

by the second repeater selector mechanism, selecting the second repeater server to serve the second resource to the client.

28. A method as recited in claim 27, wherein:

the step of selecting by the first repeater selector mechanism comprises a step for determining a Group Reduction Table and a Link Cost Table;

wherein said Group Reduction Table and said Link Cost Table are operable for use in selecting the first repeater server to serve the first resource to the first client and a step for redirecting the first client to the first repeater server.

29. A method as recited in claim 21, wherein the first request comprises an HTTP header having a first name associated with the first content provider, and wherein the second request comprises an HTTP header having a second name associated with the second content provider.

30. A method as recited in claim 29, wherein:

the first repeater server uses at least the first name and the first table on the first repeater server to identify the first origin server as an origin server from which to retrieve the first resource; and

the second repeater server uses at least the second name and the second table on the second repeater server to identify the second origin server as an origin server from which to retrieve the second resource.

31. A method as recited in claim 29, wherein the first name comprises a first hostname associated with the first content provider and the second name comprises a second hostname associated with the second content provider.

32. A method as recited in claim 21, wherein each of the repeater servers is configured to record activity related to serving resources therefrom, the method further comprising:

responsive to the act of serving (b2), recording information related to the serving of at least the first resource; and

responsive to the act of serving (c2), recording information related to the serving of at least the second resource.

33. A method as recited in claim 32, wherein the recorded information related to the serving of at least the first resource comprises a first timestamp associated with serving the first resource in response to the first request, and wherein the recorded information related to the serving of at least the second resource comprises a second timestamp associated with serving the second resource in response to the second request.

34. A method as recited in claim 33, further comprising:

collecting first information related to the serving of at least the first resource by at least some repeater servers in the shared content delivery network that have served the first resource on behalf of the first content provider during a first given period in time, the first given period in time including a first time specified by the first timestamp, said first information being derived at least in part from the recorded information related to the serving of at least the first resource in response to the first request; and

collecting second information related to the serving of at least the second resource by at least some repeater servers in the shared content delivery network that have served the second resource on behalf of the second content provider during a second given period in time, the second given period in time including a second time specified by the second timestamp, said second information being derived at least in part from the recorded information related to the serving of at least the second resource in response to the second request.

35. A method as recited in claim 21, wherein the first origin server is located in a network operated by the first content provider distinct from the shared CDN and wherein the second origin server is located in a network operated by the second content provider distinct from the first content provider network and the shared CDN.

36. A method as recited in claim 21, wherein the first repeater server obtains the copy of the first resource directly from the first origin server and wherein the second repeater server obtains the copy of the second resource directly from the second origin server.

37. A method of processing resource requests in a computer network, the method comprising:

(A) providing a shared content delivery network including a plurality of repeater servers, wherein each of the repeater servers is configured to serve resources on behalf of a plurality of content providers that subscribe to the content delivery network;

(B) responsive to a first request from a first client for a first resource, said first resource being associated with a first content provider, said first content provider being a subscriber to the content delivery network, at a first repeater server in the shared content delivery network, said first repeater server having been selected based at least in part on (i) load on said repeater servers in said shared content delivery network, and (ii) a network address corresponding to said first client;

(b1) if said first repeater server does not have said first resource, the first repeater uses at least a first table on the first repeater server and information included with the first request to determine a first origin server associated with the first resource, and said first repeater server obtaining a copy of said first resource from the first origin server; and

(b2) said first repeater server serving said first resource; and

(C) responsive to a second request from a second client, the second request being for a second resource distinct from said first resource, and said second resource being associated with a second content provider distinct from said first content provider, said second content provider being a subscriber to the content delivery network, at a second repeater server in the shared content delivery network, said second repeater server having been selected based at least in part on (i) load on said repeater servers in said shared content delivery network, and (ii) a network address corresponding to said second client;

(c1) if said second repeater server does not have said second resource, the second repeater uses at least a second table on the second repeater server and information included with the second request to determine a second origin server associated with the second resource, and said second repeater server obtaining a copy of said second resource from the second origin server; and

(c2) said second repeater server serving said second resource.

38. A method as recited in claim 37, further comprising:

providing a first repeater selector mechanism associated with the first content provider and a second repeater selector mechanism associated with the second content provider, the method further comprising;

by the first repeater selector mechanism, selecting the first repeater server to serve the first resource to the first client; and

by the second repeater selector mechanism, selecting the second repeater server to serve the second resource to the second client.

39. A method as recited in claim 37, wherein the first request comprises an HTTP header having a first name, and wherein the second request comprises an HTTP header having a second name.

40. A method as recited in claim 39, wherein:

the first repeater server uses at least the first name and the first table on the first repeater server to identify the first origin server as an origin server from which to retrieve the first resource; and

the second repeater server uses at least the second name and the table on the second repeater server to identify the second origin server as an origin server from which to retrieve the second resource.

41. A method as recited in claim 39, wherein the first name comprises a first hostname associated with the first content provider and the second name comprises a second hostname associated with the second content provider.

42. A method as recited in claim 37, wherein each of the repeater servers is configured to record activity related to serving resources therefrom,

wherein responsive to the act of serving (b2), recording information related to the serving of at least the first resource;

and

wherein responsive to the act of serving (c2), recording information related to the serving of at least the second resource.

43. A method as recited in claim 42, wherein the recorded information related to the serving of at least the first resource comprises a first timestamp associated with serving the first resource in response to the first request, and wherein the recorded information related to the serving of at least the second resource comprises a second timestamp associated with serving the second resource in response to the second request.

44. A method as recited in claim 43, further comprising:

collecting first information related to the serving of at least the first resource by at least some repeater servers in the shared content delivery network that have served the first resource on behalf of the first content provider during a first given period in time, the first given period in time including a first time specified in the first timestamp, said first information being derived at least in part from the recorded information related to the serving of at least the first resource in response to the first request; and

collecting second information related to the serving of at least the second resource by at least some repeater servers in the shared content delivery network that have served the second resource during a second given period in time, the second given period in time including a second time specified in the second timestamp, said second information being derived at least in part from the recorded information related to the serving of at least the second resource in response to the second request.

45. A method as recited in claim 37, wherein the first repeater server obtains the copy of the first resource directly from the first origin server and wherein the second repeater server obtains the copy of the second resource directly from the second origin server.