Reducing the impact of network latency on application performance

• US 9,032,096 B2
• Filed: 12/17/2004
• Issued: 05/12/2015
• Est. Priority Date: 12/17/2003
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Jawahar, Janardhanan, Kausik, Balas Natarajan
• Primary Examiner(s): Hussain, Imad
• Application Number:
  US11/014,922
• Publication Number:
  US 20080172488A1
• Time in Patent Office: 3,798 Days
• Field of Search: 709/246
• US Class Current: 709/246
• CPC Class Codes: G06F 16/9574 of access to content, e.g. by caching
• CPC Class Codes: H04L 47/70 Admission control; Resource allocation
• CPC Class Codes: H04L 47/748 Negotiation of resources, e.g. modification of a request
• CPC Class Codes: H04L 47/801 Real time traffic
• CPC Class Codes: H04L 47/83 based on usage prediction
• CPC Class Codes: H04L 67/02 based on web technology, e.g. hypertext transfer protocol [HTTP]
• CPC Class Codes: H04L 67/34 involving the movement of software or configuration parameters network booting or remote initial program loading [RIPL] G06F9/4416
• 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 67/563 Data redirection of data network streams
• CPC Class Codes: H04L 67/565 Conversion or adaptation of application format or content adding application control or application functional data H04L67/561
• CPC Class Codes: H04L 67/60 Scheduling or organising the servicing of application requests, e.g. requests for application data transmissions using the analysis and optimisation of the required network resources admission control or resource allocation H04L47/70

Abstract

An exemplary method performed by a proxy server located between a content server and a client browser for reducing effects of network latency therebetween comprises intercepting a request from the client browser for a resource at the content server, obtaining a response by the content server to the request, determining that the response would, if unmodified, require a plurality of communications between the content server and the client browser in the absence of the proxy server, modifying the response to reduce a network latency associated with the plurality of communications for accessing information located externally to the response, and transmitting the modified response to the client browser for use thereby.

Claims

1. A method for reducing effects of latency on a network connecting at least a content server and a client browser, the method comprising:

at a single proxy server located between said content server and said client browser;

intercepting a request from said client browser for a resource at said content server;

obtaining a response by said content server to said request;

evaluating whether said response would, if unmodified, require a plurality of communications by said client browser to said content server in the absence of said single proxy server;

upon determining that said response would require a plurality of communications;

obtaining information indicated by said response;

modifying said response to include the obtained information to reduce a network latency by causing a reduction in said plurality of communications by eliminating at least one additional access of said information by said client browser; and

transmitting said modified response to said client browser for use thereby; and

upon determining that said response would not require a plurality of communications;

transmitting said response to said client browser for use thereby.

2. The method of claim 1, wherein:

said obtaining a response by said content server to said request is performed over a first network that is relatively faster than a second network; and

said transmitting said modified response to said client browser is performed over said second network that is relatively slower than said first network.

3. The method of claim 2, wherein said first network is a LAN, and said second network is a WAN.

4. The method of claim 1, wherein said modifying said response includes:

obtaining said external information; and

modifying said response to include said external information.

5. The method of claim 1, wherein said response includes a redirection to another resource at a resource location distinct from a resource location from which said response was received.

6. The method of claim 5 where said resource locations are URLs.

7. The method of claim 1, wherein said response includes references to a plurality of additional resources.

8. The method of claim 7 further comprising:

obtaining the references to the plurality of additional resource locations; and

appending the references to the plurality of resource locations of said additional resources to said response, each reference being a redirect URL.

9. The method of claim 7, wherein said modifying said response includes:

enabling said client browser to open a plurality of connections to servers containing said additional resources, beyond those connections ordinarily available without modifying said response, in order to download said additional resources in a parallel fashion.

10. The method of claim 7, wherein said modifying said response includes:

creating one or more unique pseudonyms for a source of said additional resources; and

modifying resource locations of said additional resources in said response to include said unique pseudonyms, the one or more unique pseudonyms to enable additional connections with the content server to be opened.

11. The method of claim 10, further comprising:

adding one or more entries into a domain name server to link said unique pseudonyms to said proxy server.

12. The method of claim 10, further comprising:

adding one or more entries into a domain name server to link said unique pseudonyms to said source.

13. The method of claim 12, wherein said source is said content server.

14. The method of claim 10, wherein at least one of said additional resources is multiply referenced, and further comprising using a common pseudonym for said multiply-referenced additional resource.

15. The method of claim 10, wherein at least one of said additional resources is multiply-referenced, and further comprising generating a common pseudonym for said multiply-referenced additional resource based on its content.

16. The method of claim 10, wherein at least one of said additional resources is multiply referenced, and further comprising generating a common pseudonym for said multiply-referenced additional resource based on its URL.

17. The method of claim 10, wherein at least one of said additional resources is referenced by a relative URL, and further comprising:

converting said relative URL to an absolute URL; and

introducing a unique pseudonym to said absolute URL.

18. The method of claim 1, conditioned upon latency testing, including determining and taking into account the effect of differential latency between a server-to-proxy network segment and a proxy-to-client network segment.

19. The method of claim 1, conditioned upon latency testing, including determining that an expected latency reduction exceeds an expected proxy server processing time.

20. The method of claim 1, wherein said obtaining a response by said content server to said request includes obtaining said response from a cache.

21. The method of claim 20, wherein said response was cached from a previous communication.

22. The method of claim 20, wherein said response is precomputed from an expected communication.

23. The method of claim 1, wherein said modified response is in a so-called MIME HTML format.

24. The method of claim 1, conditioned upon determining that said client browser can recognize said modified response.

25. The method of claim 24, further comprising downloading a supplementary application to said client upon determining that said client browser cannot recognize said modified response.

67. The method of claim 1, wherein modifying said response comprises:

determining that said response contains a reference to an embedded

object;

requesting said embedded object based; and

appending said embedded object to said response.

68. The method of claim 67, wherein the embedded object is an image file.

26. A single proxy server to be disposed between a content server and a client browser, for reducing effects of latency on a network communication therebetween, the single proxy server comprising:

a processor; and

a computer-readable memory including computer-readable instructions that, when executed using said processor performs operations comprising;

intercepting a request from said client browser for a resource at said content server;

obtaining a response by said content server to said request;

evaluating whether said response would, if unmodified, require a plurality of communications by said client browser to said content server in the absence of said single proxy server;

upon determining that said response would require a plurality of communications;

obtaining information indicated by said response;

modifying said response to include the obtained information to reduce a network latency by causing a reduction in said plurality of communications by eliminating at least one additional access of said information by said client browser; and

transmitting said modified response to said client browser for use thereby; and

upon determining that said response would not require a plurality of communications;

transmitting said response to said client browser for use thereby.

27. The proxy server of claim 26, wherein:

said obtaining a response by said content server to said request performed over a first network that is relatively faster than a second network; and

said transmitting said modified response to said client browser is performed over said second network that is relatively slower than said first network.

28. The proxy server of claim 27, wherein said first network is a LAN, and said second network is a WAN.

29. The proxy server of claim 26, wherein said modifying said response includes computer-readable instructions that, when executed using said processor:

obtain said external information; and

modify said response to include said external information.

30. The proxy server of claim 26, wherein said response includes a redirection to another resource at a resource location distinct from a resource location from which said response was received.

31. The proxy server of claim 26, wherein said response includes a reference to a plurality of additional resources.

32. The proxy server of claim 31, wherein said modifying said response includes computer-readable instructions that, when executed using said processor:

enable said client browser to open a plurality of connections to servers containing said additional resources, beyond those connections ordinarily available without modifying said response, in order to download said additional resources in a parallel fashion.

33. The proxy server of claim 31, wherein said modifying said response includes computer-readable instructions that, when executed using said processor:

create one or more unique pseudonyms for a source of said additional resources; and

modify resource locations of said additional resources in said response to include said unique pseudonyms, the one or more unique pseudonyms to enable additional connections with the content server to be opened.

34. A non-transitory computer-readable medium on a single proxy server located between a content server and a client browser for reducing effects of latency on a network connecting at least said content server and said client browser, comprising logic instructions capable of being executed to perform operations comprising:

intercepting a request from said client browser for a resource at said content server;

obtaining a response by said content server to said request;

evaluating whether said response would, if unmodified, require a plurality of communications by said client browser to said content server in the absence of said single proxy server;

upon determining that said response would require a plurality of communications;

obtaining information indicated by said response;

modifying said response to include the obtained information to reduce a network latency by causing a reduction in said plurality of communications by eliminating at least one additional access of said information by said client browser; and

transmitting said modified response to said client browser for use thereby; and

upon determining that said response would not require a plurality of communications;

transmitting said response to said client browser for use thereby.

35. The computer-readable medium of claim 34, wherein:

said obtaining a response by said content server to said request performed over a first network that is relatively faster than a second network; and

said transmitting said modified response to said client browser is performed over said second network that is relatively slower than said first network.

36. The computer-readable medium of claim 35, wherein said first network is a LAN, and said second network is a WAN.

37. The computer-readable medium of claim 34, wherein said modifying said response includes computer-readable instructions that, when executed using said processor:

obtain said external information; and

modify said response to include said external information.

38. The computer-readable medium of claim 34, wherein said response includes a redirection to another resource at a resource location distinct from a resource location from which said response was received.

39. The computer-readable medium of claim 34, wherein said response includes a reference to a plurality of additional resources.

40. The computer-readable medium of claim 39, wherein said modifying said response includes computer-readable instructions that, when executed using said processor:

enable said client browser to open a plurality of connections to servers containing said additional resources, beyond those connections ordinarily available without modifying said response, in order to download said additional resources in a parallel fashion.

41. The computer-readable medium of claim 39, wherein said modifying said response includes computer-readable instructions that, when executed using said processor:

create one or more unique pseudonyms for a source of said additional resources; and

modify resource locations of said additional resources in said response to include said unique pseudonyms, the one or more unique pseudonyms to enable additional connections with the content server to be opened.

42. Apparatus for reducing effects of latency on a network communication between a content server and a client browser, the apparatus comprising:

at a single proxy server between said content server and said client browser;

means for obtaining a response to a request from said client browser for a resource from said content server;

means for evaluating whether said response would, if unmodified, require a plurality of communications by said client browser to said content server in the absence of said single proxy server;

means for obtaining information indicated by said response;

means for modifying, upon determining that said response would require a plurality of communications, said response to include the obtained information to reduce a network latency by causing a reduction in said plurality of communications via eliminating at least one additional access of said information by said client browser; and

means for forwarding said modified response to said client browser for use thereby; and

means for forwarding said response to said client browser for use thereby upon determining that said response would not require a plurality of communications.

43. A method for reducing network latency on a network connecting a content server to a client browser, the method comprising:

at a single proxy server between said content server and said client browser;

intercepting a request from said client browser for a resource at said content server;

obtaining a response from said content server to said request;

evaluating whether said response is a redirection to another resource;

upon determining that said response is a redirection;

obtaining said another resource based on the determining that said response is said redirection to another resource; and

sending said another resource to said client browser, the sending of said another resource causing a reduction in communications by eliminating at least one additional access of information by said client browser for said another resource; and

upon determining that said response is not a redirection, sending said response to said client browser.

44. The method of claim 43, wherein:

said obtaining said another resource is performed over a first network that is relatively faster than a first network.

45. The method of claim 44, wherein said first network is a LAN said second network is a WAN.

46. The method of claim 43, further comprising between said obtaining said another resource and sending said another resource:

modifying said response to include said another resource.

47. A method for reducing network latency on a network connecting a content server to a client browser, the method comprising:

at a single proxy server between said content server and said client browser;

intercepting a request from said client browser for a resource at said content server;

obtaining a response from said content server to said request;

evaluating whether said response includes a reference to at least one additional resource external to said response;

upon determining that said response includes a reference to at least one additional resource external to said response;

obtaining said additional resource;

modifying said response to include said additional resource, the modifying of said response causing a reduction in communications by eliminating at least one additional access of information by said client browser; and

sending said modified response to said client browser; and

upon determining that said response does not include a reference to at least one additional resource external to said response, sending said response to said client browser.

48. The method of claim 47, wherein:

said obtaining said additional resource is performed over a first network that is relatively faster than a second network; and

said sending said modified response is performed over said second network that is relatively slower than said first network.

49. The method of claim 48, wherein said first network is a LAN, and said second network is a WAN.

50. The method of claim 47, wherein said modifying said response includes:

appending said additional resources to said response.

51. The method of claim 50 further comprising:

appending resource locations of said additional resources to said response.

52. The method of claim 47, conditioned upon latency testing, including determining and taking into account the effect of differential latency between a server-to-proxy network segment and a proxy-to-client network segment.

53. The method of claim 47, conditioned upon latency testing, including determining that an expected latency reduction exceeds an expected proxy server processing time.

54. The method of claim 47, wherein said obtaining a response includes obtaining said response from a cache.

55. The method of claim 47, wherein said modified response is in a so-called MIME HTML format.

56. The method of claim 47, conditioned upon determining that said client browser can recognize said modified response.

57. The method of claim 56, further comprising downloading a supplementary application to said client upon determining that said client browser cannot recognize said modified response.

58. A method for reducing network latency on a network connecting a content server to a client browser, the method comprising:

at a single proxy server between said content server and said client browser;

intercepting a request from said client browser for a resource at said content server;

obtaining a response from said content server to said request;

evaluating whether said response includes a reference to more than two additional resources external to said response;

upon determining that said response includes a reference to more than two additional resources external to said response;

modifying said response to include one or more unique pseudonyms to enable said client browser to download said additional resources at substantially the same time by enabling additional connections with the content server to be opened; and

sending said modified response to said client browser; and

upon determining that said response does not include a reference to more than two additional resources external to said response, sending said response to said client browser.

59. The method of claim 58, wherein said modifying said response includes:

creating the one or more unique pseudonyms for a source of said additional resources; and

modifying said response comprises modifying resource locations of said additional resources in said response to include said unique pseudonyms, the one or more unique pseudonyms to enable said additional connections with the content server to be opened.

60. The method of claim 59, further comprising:

adding one or more entries into a domain name server to link said unique pseudonyms to said proxy server.

61. The method of claim 59, further comprising:

adding one or more entries into a domain name server to link said unique pseudonyms to said source.

62. The method of claim 61, wherein said source is said content server.

63. The method of claim 58, wherein at least one of said additional resources is multiply referenced, and further comprising using a common pseudonym for said multiply-referenced additional resource.

64. The method of claim 58, wherein at least one of said additional resources is multiply referenced, and further comprising generating a common pseudonym for said multiply-referenced additional resource based on its content.

65. The method of claim 58, wherein at least one of said additional resources is multiply referenced, and further comprising generating a common pseudonym for said multiply-referenced additional resource based on its URL.

66. The method of claim 58, wherein at least one of said additional resources is referenced by a relative URL, and further comprising:

converting said relative URL to an absolute URL; and

introducing a unique pseudonym to said absolute URL.