Transparent Redirection Of Resource Requests

• US 20110219120A1
• Filed: 05/16/2011
• Published: 09/08/2011
• Est. Priority Date: 02/10/1998
• Status: Active Grant

• Current Assignee: Level 3 Communications LLC (Lumen Technologies, Inc.)
• Original Assignee: Level 3 Communications LLC (Lumen Technologies, Inc.)
• Inventors: Greer, Richard E., Farber, David A., Swart, Andrew D., Balter, James A.
• Granted Patent: US 8,473,613 B2
• Time in Patent Office: Days
• US Class Current: 709/226
• 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 plurality of repeater servers form a shared content delivery network (CDN) to serve resources to clients on behalf of a plurality of content providers. First and second resources are associated with a first content provider, the first resource referencing the second resource. The second resource is associated with a domain of the shared CDN. Responsive to a request that causes the first resource to be served to a client from a server in a domain associated with the first content provider, a CDN server is identified in the domain associated with the shared CDN to serve the second resource to the client. The CDN server is selected based, at least in part, on load conditions on at least some of the CDN servers, and on the client'"'"'s location. Responsive to the CDN server being requested to serve the second resource: if a copy of the second resource is available on the CDN server, the copy is served to the client from the CDN server; otherwise, the second resource is replicated on the CDN server and then served to the client from the CDN server.

Claims

1. A method for processing resource requests in a computer network, the method comprising:

providing a repeater server network comprising a plurality of repeater servers, wherein each of the plurality of repeater servers is operable to serve to clients resources that are deemed repeatable;

intercepting a client request issued by a client, wherein the client request is associated with a resource requested by the client;

analyzing the client request to determine whether the resource is repeatable;

if it is determined that the resource is repeatable, then causing the client to be provided with an identifier of at least one repeater server in the repeater server network, wherein if the resource is not determined to be repeatable, the client is served the resource by a server distinct from the plurality of repeater servers.

2. A method as recited in claim 1, further comprising, by the at least one repeater server in the repeater server network:

receiving a second request by the client to serve the resource;

determining whether a copy of the resource is located on the at least one repeater server;

if the resource is not located on the at least one repeater server, then obtaining a copy of the resource from another server prior to serving the resource to the client, wherein the other server is distinct from the plurality of repeater servers.

3. A method as recited in claim 2, wherein the other server distinct from the repeater server network is an origin server on which the resource is maintained.

4. A method as recited in claim 1, further comprising, by the at least one repeater server in the repeater server network:

receiving a second request by the client to serve the resource;

determining whether a copy of the resource is located on the at least one repeater server;

if the resource is not located on the at least one repeater server, then obtaining a copy of the resource from another repeater server prior to serving the resource to the client, wherein the other repeater server is distinct from the at least one repeater server.

5. A method as recited in claim 1, wherein the identifier of the at least one repeater server comprises an alphanumeric string.

6. A method recited in claim 1, further comprising:

if the resource is determined to be repeatable, selecting the at least one repeater server from the plurality of repeater servers based at least on a measure of network cost between at least the at least one repeater server and the client.

7. A method recited in claim 1, further comprising:

if the resource is determined to be repeatable, selecting the at least one repeater server from the plurality of repeater servers based at least on a load measurement comparison of at least some of the plurality of repeater servers including the at least one repeater server.

8. A method as recited claim 1, further comprising:

comparing information contained in the client request with regular expression patterns of repeatable resources.

9. A method for processing resource requests in a computer network, the method comprising:

providing a repeater server network comprising a plurality of repeater servers;

by a reflector;

receiving a request from a client in response to the client requesting a resource;

analyzing the request to determine whether to direct the client to a repeater server from which to retrieve the resource;

if the analyzing act determines to direct the request to a repeater server, then causing the client to be provided with an identifier of at least one repeater server in the repeater server network;

if the analyzing act determines not to direct the request to a repeater server, then causing the client to retrieve the resource from another server distinct from the plurality of repeater servers;

by the at least one repeater server;

receiving a second request by the client to serve the resource;

determining whether a copy of the resource is located on the at least one repeater server; and

if the resource is not located on the at least one repeater server, then obtaining a copy of the resource from another server prior to serving the resource to the client.

10. A method as recited in claim 9, wherein the other server that is distinct from the plurality of repeater servers is an origin server identified by information in the request.

11. A method as recited in claim 10, wherein the reflector is co-located with the origin server.

12. A method as recited in claim 11, wherein the other server from which the copy of the resource is obtained by the at least one repeater server is the origin server.

13. A method as recited in claim 9, wherein the other server from which the copy of the resource is obtained by the at least one repeater server is a peer repeater server.

14. A method as recited in claim 9, further comprising:

if the analyzing act determines to direct the request to a repeater server, selecting, by the reflector, the at least one repeater server from the plurality of repeater servers based on a measure of network cost between at least the at least one repeater server and the client.

15. A method as recited in claim 9, further comprising:

if the analyzing act determines to direct the request to a repeater server, selecting, by the reflector, the at least one repeater server from the plurality of repeater servers based at least on a load measurement comparison of at least some of the plurality of repeater servers including the at least one repeater server.

16. A system for processing resource requests in a computer network, the method comprising:

a repeater server network comprising a plurality of repeater servers; and

a reflector operable to receive requests from clients in response to the clients requesting resources, to analyze each request to determine whether to direct a client to a repeater server from which to retrieve a resource, and if so, then to provide the client with an identifier of at least one repeater server in the repeater server network if the reflector determines to direct a request to a repeater server.

17. A system as recited in claim 16, wherein the at least one repeater server is operable to receive an HTTP request by the client to serve the resource, and in response to the HTTP request, to obtain a copy of the resource from another server prior to serving the resource to the client.

18. A system as recited in claim 17, further comprising:

an origin server co-located with the reflector, wherein the request is directed to the origin server if the reflector determines not to direct the client to a repeater server.

19. A system as recited in claim 18, wherein the reflector is operable to receive requests from clients by taking over at least the port number of the origin server.

20. A system as recited in claim 19, wherein the reflector is operable to receive requests from clients by also taking over at least the Internet Protocol address of the origin server.

21. A system as recited in claim 18, wherein the origin server is identified by information in the requests.

22. A system as recited in claim 18, wherein the other server from which the copy of the resource is obtained by the at least one repeater server is the origin server.

23. A system as recited in claim 17, wherein the other server from which the copy of the resource is obtained by the at least one repeater server is a peer repeater server.

24. A system as recited in claim 16, further comprising:

a table accessible by the reflector and comprising information for use by the reflector in determining whether to direct a client to a repeater server from which to retrieve a resource.

25. A system as recited in claim 24, wherein the information contained in the table comprises regular expression patterns of repeatable resources.

26. A system as recited in claim 16, wherein the at least one repeater server is selected by the reflector from the plurality of repeater servers based at least on a measure of network cost between at least the at least one repeater server and the client.

27. A system as recited in claim 16, wherein the at least one repeater server is selected by the reflector from the plurality of repeater servers based at least on a load measurement comparison of at least some of the plurality of repeater servers including the at least one repeater server.

28. A system as recited in claim 16, wherein the identifier of the at least one repeater server comprises an alphanumeric string.

29. A system for processing resource requests in a computer network, the method comprising:

at least one repeater server; and

a reflector operable to receive requests from clients in response to the clients requesting resources, to analyze each request to determine whether to direct a client to the at least one repeater server from which to retrieve a resource, and if so, then to provide the client with an identifier of the at least one repeater server if the reflector determines to direct a request to a repeater server; and

a table accessible by the reflector and system information for use by the reflector in determining whether to direct a client to a repeater server from which to retrieve a resource.

30. A system as recited in claim 29, wherein the at least one repeater server is operable to receive an HTTP request by the client to serve the resource, and in response to the HTTP request, obtain a copy of the resource from another server prior to serving the resource to the client.

31. A system as recited in claim 30, further comprising:

an origin server co-located with the reflector, wherein the request is directed to the origin server if the reflector determines not to direct the client to a repeater server.

32. A system as recited in claim 31, wherein the reflector is operable to receive requests from clients by taking over at least the port number of the origin server.

33. A system as recited in claim 32, wherein the reflector is operable to receive requests from clients by also taking over at least the Internet Protocol address of the origin server.

34. A system as recited in claim 31, wherein the origin server is identified by information in the requests.

35. A system as recited in claim 31, wherein the other server from which the copy of the resource is obtained by the at least one repeater server is the origin server.

36. A system as recited in claim 30, wherein the other server from which the copy of the resource is obtained by the at least one repeater server is a peer repeater server.

37. A system as recited in claim 29, wherein the information contained in the table comprises regular expression patterns of repeatable resources.

38. A system as recited in claim 29, further comprising:

a plurality of repeater servers, wherein the at least one repeater server is selected by the reflector from the plurality of repeater servers based at least on a measure of network cost between at least the at least one repeater server and the client.

39. A system as recited in claim 29, further comprising:

a plurality of repeater servers, wherein the at least one repeater server is selected by the reflector from the plurality of repeater servers based at least on a load measurement comparison of at least some of the plurality of repeater servers including the at least one repeater server.

40. A method for processing resource requests in a computer network, the method comprising:

providing at least one repeater server;

intercepting a resource served from an origin server in response to a request issued by a client and associated with a requested resource, wherein the requested resource comprises a plurality of embedded resources represented by identifiers;

replacing at least some of the identifiers with alternative identifiers designating the at least one repeater server; and

providing the requested resource with the alternative identifiers to the client.

41. A method as recited in claim 40, further comprising:

analyzing the resource to determine whether the client should be directed to the at least one repeater server to retrieve the embedded resources, wherein the at least some identifiers are selected based on the analyzing act.

42. A system for processing resource requests in a computer network, the method comprising:

a first server operable to store and serve resources to clients;

at least one repeater server; and

a reflector operable to intercept requests from clients directed to the first server, to analyze each request to determine whether to direct a client to the at least one repeater server from which to retrieve a resource associated with the request, and if so, then to provide the client with an identifier of at least one repeater server if the reflector determines to direct a request to the at least one repeater server.

43. A system as recited in claim 42, wherein the at least one repeater server is operable to receive an HTTP request by the client to serve the resource, and in response to the HTTP request, obtain a copy of the resource from another server prior to serving the resource to the client.

44. A system as recited in claim 43, wherein the other server comprises a peer repeater server.

45. A system as recited in claim 43, wherein the other server is the first server.

46. A system as recited in claim 42, wherein the reflector forwards the request to the first server if the reflector determines not to direct the client to a repeater server.

47. A system as recited in claim 46, wherein the first server and the reflector are colocated.

48. A system as recited in claim 42, further comprising:

a plurality of repeater servers, wherein the at least one repeater server is selected by the reflector from the plurality of repeater servers based at least on a measure of network cost between at least the at least one repeater server and the client.

49. A system as recited in claim 42, wherein the reflector is operable to receive requests from clients by taking over at least the port number of the first server.

50. A system as recited in claim 49, wherein the reflector is operable to receive requests from clients by also taking over at least the Internet Protocol address of the second server.