SYSTEMS AND METHODS OF USING HTTP HEAD COMMAND FOR PREFETCHING

• US 20080229023A1
• Filed: 03/12/2007
• Published: 09/18/2008
• Est. Priority Date: 03/12/2007
• Status: Active Grant

• Current Assignee: Citrix Systems, Inc. (Cloud Software Group)
• Original Assignee: Citrix Systems, Inc. (Cloud Software Group)
• Inventors: Plamondon, Robert
• Granted Patent: US 7,809,818 B2
• Time in Patent Office: Days
• US Class Current: 711/126
• CPC Class Codes: G06F 12/0862 with prefetch
• CPC Class Codes: G06F 12/0875 with dedicated cache, e.g. instruction or stack
• 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 67/5681 Pre-fetching or pre-delivering data based on network characteristics
• CPC Class Codes: H04L 67/5682 Policies or rules for updating, deleting or replacing the stored data

Abstract

The present solution provides a variety of techniques for accelerating and optimizing network traffic, such as HTTP based network traffic. The solution described herein provides techniques in the areas of proxy caching, protocol acceleration, domain name resolution acceleration as well as compression improvements. In some cases, the present solution provides various prefetching and/or prefreshening techniques to improve intermediary or proxy caching, such as HTTP proxy caching. In other cases, the present solution provides techniques for accelerating a protocol by improving the efficiency of obtaining and servicing data from an originating server to server to clients. In another cases, the present solution accelerates domain name resolution more quickly. As every HTTP access starts with a URL that includes a hostname that must be resolved via domain name resolution into an IP address, the present solution helps accelerate HTTP access. In some cases, the present solution improves compression techniques by prefetching non-cacheable and cacheable content to use for compressing network traffic, such as HTTP. The acceleration and optimization techniques described herein may be deployed on the client as a client agent or as part of a browser, as well as on any type and form of intermediary device, such as an appliance, proxying device or any type of interception caching and/or proxying device.

Claims

1. A method for determining by a device whether to prefetch an object identified from a page by fetching header information of the object from a remote object server, the method comprising:

(a) receiving, by a device, a page including an identifier of an object;

(b) transmitting, by the device, a request generated by the device to obtain header information of the object from a remote object server;

(c) receiving, by the device, in response to the generated request, header information for the object; and

(d) determining, by the device, responsive to the received header information whether to prefetch the object from the remote object server.

2. The method of claim 1, wherein step (d) comprises determining, by the device, responsive to the received information, to store the object in a cache.

3. The method of claim 1, comprising identifying, by the device, the identifier of the object from the page, and determining the object is not stored in a cache.

4. The method of claim 1, comprising forwarding, by the device, the page to one of a user, a client or a browser.

5. The method of claim 1, wherein one of step (b), step (c) or step (d) is performed prior to a user requesting the object from the page.

6. The method of claim 1, wherein step (a) comprises intercepting the page including a hyperlink identifying an object.

7. The method of claim 1, wherein step (b) comprises transmitting, by the device, an HTTP HEAD command to a remote object server identified by a uniform resource locator associated with the object of the page.

8. The method of claim 1, wherein step (c) comprises receiving, in response to the generated request, header information of the object identifying a maximum amount of time for which the object is valid.

9. The method of claim 1, wherein step (c) comprises receiving, in response to the generated request, header information of the object identifying a date on which the object was last modified.

10. The method of claim 1, wherein step (d) comprises determining, responsive to the received header information, to identify the object already stored in a cache as valid.

11. The method of claim 1, wherein step (d) comprises determining, responsive to the received header information, to modify the time period for which an object that is already stored in a cache is valid.

12. The method of claim 1, comprising transmitting, by the device, a request to obtain the object from the remote object server in response to the received header information.

14. The method of claim 1 where step (d) comprises determining, responsive to the received header information, to modify a time period for which an object that is already stored in a cache is valid.

15. The method of claim 1, wherein the device comprises one of a client or an appliance intercepting and forwarding communications between a client and a server.

30. The device of claim 15, wherein the device is one of a client an appliance intercepting and forwarding communications between the client and the server.

13. The method of claim 13, comprising storing, by the device, in a cache the object received from the remote object server.

16. A device for determining whether to prefetch an object identified from an intercepted page by fetching header information of the object from a remote object server, the device comprising:

means for receiving a page including an identifier of an object;

means for transmitting a request generated by the device to obtain header information of the object from a remote object server;

means for receiving in response to the generated request, a header for the object; and

means for determining responsive to the received header information whether to prefetch the object from the remote object server.

17. The device of claim 16, wherein the device determines, responsive to the received information, to store the object in a cache.

18. The device of claim 16, wherein the device identifies the identifier of the object from the page, and determines the object is not stored in a cache.

19. The device of claim 16, wherein the device forwards the page to one of a user, a client or a browser.

20. The device of claim 16, wherein the device transmits the generated request to the remote object server prior to a user requesting the object.

21. The device of claim 16, comprising means for receiving the page including a hyperlink identifying an object.

22. The device of claim 16, wherein the device transmits an HTTP HEAD command to the remote object server identified by a uniform resource locator associated with the object of the intercepted page.

23. The device of claim 16, wherein the device receives, in response to the generated request, header information of the object identifying a maximum amount of time for which the object is valid.

24. The device of claim 16, wherein the device receives, in response to the generated request, header information of the object identifying a date on which the object was last modified.

25. The device of claim 16, wherein the device determines, responsive to the received header information, to identify the object already stored in a cache as valid.

26. The device of claim 16, wherein the device determines responsive to the received header information, to modify the time period for which an object that is already stored in a cache is valid.

27. The device of claim 16, wherein the device transmits a request to obtain the object from the remote object server in response to the received header information.

28. The device of claim 27, wherein the device stores the object received from the remote object server in a cache.

29. The device of claim 16, wherein the device determines, responsive to the received header information, to modify a time period for which an object that is already stored in a cache is valid.

31. A method for prefetching by a device header information of an object from a remote object server, the method comprising:

(a) receiving, by a device, a page including an identifier of an object;

(b) determining, by the device, that a header of the object identified by the page is stored in a cache; and

(c) generating, by the device in response to the determination, a request for the header of the object from a remote object server prior to the user requesting the object from the page.

32. The method of claim 31, comprising receiving, by the device, in response to the generated request, header information for the object.

33. The method of claim 32, comprising updating, by the device, the cached header information based on the received header information.

34. The method of claim 31, comprising receiving, by the device, a request from a requester for the header information of the object.

35. The method of claim 34, comprising transmitting, by the device, the header information stored in the cache to the requester.

36. The method of claim 34, wherein the request comprises an HTTP HEAD command.

37. The method of claim 34, wherein the request comprises an HTTP GET command using an “

if-modified-since”

.

38. The method of claim 37, comprising determining, by the device, the object of the request has not been modified, and responding to the request with the header information stored in the cache.

39. The method of claim 34, comprising determining, by the device, the object of the request has been modified and in response to the determination, forwarding the request to a server.

40. The method of claim 39, comprising receiving, by the device, the object from the request.

41. The method of claim 40, comprising responding, by the device, to the request with the object received from the server.

42. The method of claim 40, comprising storing, by the device, the object to the cache.

43. A device for prefetching by a device header information of an object from a remote object server, the device comprising:

means for receiving a page including an identifier of an object;

means for determining that a header of the object identified by the page is stored in a cache; and

means for generating, in response to the determination, a request for the header of the object from a remote object server prior to the user requesting the object from the page.

44. The device of claim 43, comprising means for receiving, by the device, in response to the generated request, header information for the object.

45. The device of claim 44, comprising means for updating the cached header information based on the received header information.

46. The device of claim 43, comprising means for receiving a request from a requester for the header information of the object.

47. The device of claim 46, comprising transmitting the header information stored in the cache to the requester.

48. The device of claim 46, wherein the request comprises an HTTP HEAD command.

49. The device of claim 46, wherein the request comprises an HTTP GET command using an “

if-modified-since”

.

50. The device of claim 49, comprising means for determining that the object of the request has not been modified, and responding to the request with the header information stored in the cache.

51. The device of claim 46, comprising means for determining that the object of the request has been modified and in response to the determination, forwarding the request to a server.

52. The device of claim 51, comprising means for receiving the object from the request.

53. The device of claim 52, comprising means for responding to the request with the object received from the server.

54. The device of claim 52, comprising means for storing the object to the cache.

55. The device of claim 43, wherein the device is one of a client or an appliance intercepting and forwarding communications between the client and a server.