SYSTEMS AND METHODS OF PREFRESHENING CACHED OBJECTS BASED ON USER'S CURRENT WEB PAGE

• US 20080228772A1
• 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 8,504,775 B2
• Time in Patent Office: Days
• US Class Current: 707/10
• CPC Class Codes: G06F 16/9574 of access to content, e.g. by caching

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 refreshing cached objects based on user requests for pages identifying the cached objects, the method comprising:

(a) receiving, by a device, a page via a network, the page identifying an object;

(b) forwarding, by the device, the page to a user requesting the page;

(c) determining, by the device, that the object is stored in a cache; and

(d) transmitting, by the device, a request for a status of the object to a remote object server prior to the user requesting the object from the page.

2. The method of claim 1, wherein step (d) comprises transmitting, by the device to the remote object server, responsive to the determination, a conditional request to retrieve the object.

3. The method of claim 1, comprising receiving, by the device, in response to the request, an indication from the remote object server that the object is valid.

4. The method of claim 1, comprising receiving, by the device, in response to the request, an updated version of the object from the remote object server.

5. The method of claim 1, wherein step (c) comprises determining, by the device, an expiry of the object has expired.

6. The method of claim 1, wherein step (c) comprises determining, by the device, the object is stale.

7. The method of claim 1, determining, by the device, that the remote object server is not available to provide the object, and not serving the object from the cache in response to the determination.

8. The method of claim 1, determining, by the device, that the remote object server does not allow the user access to the object, and not serving the object from the cache in response to the determination.

9. The method of claim 1 wherein step (c) comprises determining that the object exists in the cache and that a status identifier associated with the object indicates that the object is valid.

10. The method of claim 8, wherein step (d) comprises not transmitting, by the device, the request to the remote object server in response to the determination.

11. The method of claim 1, wherein step (c) comprises determining that a size of the object is below a predetermined threshold and transmitting the request for the status of the object to the remote object server in response to the determination.

12. The method of claim 1, comprising identifying, by the device, one or more levels of the page having objects, determining objects at each of the one or more levels are located in the cache, and transmitting requests for a status of the objects to the remote object server in response to the determination.

13. The method of claim 12, comprising transmitting, by the device, the requests prior to the user requesting a level from the one or more levels of the page.

14. The method of claim 1, comprising identifying, by the device, the request to the remote object server as a speculative request.

15. The method of claim 1, wherein the device comprises one of a client or a server.

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

17. A device for refreshing cached objects based on user requests for pages identifying the object, the device comprising:

means for receiving a page via a network, the page identifying an object;

means for forwarding the page to a user requesting the page;

means for determining that the object is stored in a cache; and

means for transmitting a request for a status of the object to a remote object server prior to the user requesting the object from the page.

18. The device of claim 17, wherein the device transmits to the remote object server, responsive to the determination, a conditional request to retrieve the object.

19. The device of claim 17, wherein the device receives in response to the request an indication from the remote object server that the object is valid.

20. The device of claim 17, wherein the device receives in response to the request an updated version of the object from the remote object server.

21. The device of claim 17, wherein the device determines an expiry of the object has expired.

22. The device of claim 17, wherein the device determines the object is stale.

23. The device of claim 17, wherein the device determines that the remote object server is not available to provide the object, and does not serve the object from the cache in response to the determination.

24. The device of claim 17, wherein the device determines that the remote object server does not allow the user access to the object, and does not server the object from the cache in response to the determination.

25. The device of claim 17, wherein the device comprises determining that the object exists in the cache and that a status identifier associated with the object indicates that the object is valid.

26. The device of claim 25, wherein the device does not transmit the request to the remote object server in response to the determination.

27. The device of claim 17, wherein the device determines that a size of the object is below a predetermined threshold and transmits the request for the status of the object to the remote object server in response to the determination.

28. The device of claim 17, wherein the device identifies one or more levels of the page having objects, determining objects at each of the one or more levels are located in the cache, and transmits requests for a status of the objects to the remote object server in response to the determination.

29. The device of claim 28, wherein the device transmits the requests prior to the user requesting a level from the one or more levels of the page.

30. The device of claim 17, wherein the device identifies the request to the remote object server as a speculative request.

31. The device of claim 17, wherein the device comprises one of a client or a server.

32. The device of claim 17, wherein the device intercepts and forwards communications between a client and a server.

33. In a networked environment including a network appliance acting as a proxy between a client requesting pages and a server responding to client requests, a method for refreshing objects cached by the appliance, the method comprising:

(a) receiving, by the appliance, a page transmitted by a server to a client in response to a request from a user of the client, the page identifying an object;

(b) forwarding, by the appliance, the intercepted page to the client;

(c) determining, by a cache manager of the appliance, that the object is stored in a cache of the appliance; and

(d) transmitting, by the appliance, a request for a status of the object to the server prior to the user of the client requesting the object from the page.

34. The method of claim 33, comprising transmitting, by the appliance, to the server, responsive to the determination, a conditional request to retrieve the object.

35. The method of claim 33, comprising receiving, by the appliance, in response to the request, an indication from the remote object server that the object is valid.

36. The method of claim 33, comprising receiving, by the appliance, in response to the request, an updated version of the object from the remote object server.

37. The method of claim 33, comprises determining, by the cache manager, an expiry of the object has expired.

38. The method of claim 33, comprises determining, by the cache manager, the object is stale.

39. The method of claim 33, determining, by the appliance, that the server is not available to provide the object, and not serving the object from the cache in response to the determination.

40. The method of claim 33, determining, by the appliance, that the server does not allow the user access to the object, and not serving the object from the cache in response to the determination.

41. The method of claim 33, comprising determining, by the cache manager, the object exists in the cache and that a status identifier associated with the object indicates that the object is valid.

42. The method of claim 41, comprising not transmitting, by the appliance, the request to the remote in response to the determination.

43. The method of claim 33, comprising determining, by the cache manager, that a size of the object in the cache is below a predetermined threshold and transmitting by the appliance the request for the status of the object to the remote object server in response to the determination.

44. The method of claim 33, comprising identifying, by the appliance, one or more levels of the page having objects, determining, by the cache manager, objects at each of the one or more levels are located in the cache, and transmitting, by the appliances, requests for a status of the objects to the server in response to the determination.

45. The method of claim 33, comprising transmitting, by the appliance, the requests prior to the user requesting a level from the one or more levels of the page.

46. The method of claim 33, comprising identifying, by the appliance, the request to the server as a speculative request.