Systems and Methods of Providing A Multi-Tier Cache

• US 20080229020A1
• 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 8,074,028 B2
• Time in Patent Office: Days
• US Class Current: 711/122
• CPC Class Codes: G06F 12/0813 with a network or matrix configuration
• CPC Class Codes: G06F 12/0888 using selective caching, e.g. bypass
• CPC Class Codes: H04L 61/4511 using domain name system [DNS]
• 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 of storing objects in a cache using multiple storage tiers based on size of objects and maintaining a number of smaller objects stored to the cache within a predetermined threshold, the method comprising the steps of:

(a) establishing a size of a storage for a cache to store cached objects, the cache using a first portion of the storage for storing objects smaller than or equal to a first threshold object size and a second portion of the storage for storing objects larger than the first threshold object size;

(b) identifying a number of objects the cache is allowed to store to the first portion of the storage;

(c) receiving an object for caching;

(d) determining to store the object in one of the first portion of the storage or the second portion of the storage based on a size of the object; and

(e) maintaining the number of objects the cache is allowed to store to the first portion of the storage below a predetermined threshold.

2. The method of claim 1, comprising determining the size of the object is smaller than or equal to the first threshold object size and storing the object in the first portion of the storage.

3. The method of claim 1, comprising determining the size of the object is larger than the first threshold object size and storing the object in the second portion of the storage.

4. The method of claim 1, comprising determining the number of objects stored to the first portion of the storage has reached the predetermined threshold.

5. The method of claim 4, comprising not storing the received object in the cache based on the determination that the number of objects stored to the first portion of the storage has reached the predetermined threshold.

6. The method of claim 4, comprising removing a previously cached object from the cache based on the determination that the number of objects stored to the first portion of the storage has reached the predetermined threshold, and storing the received object in the cache.

7. The method of claim 1, comprising establishing a predetermined size of the second portion of storage for storing objects larger than the first threshold object size.

8. The method of claim 1, comprising identifying a second threshold object size for storing objects in the first portion of the storage.

9. The method of claim 8, comprising receiving a second object for caching, and storing the second object in the first portion of the storage responsive to determining a size of the second object is greater than the second threshold object size and less than the first threshold object size.

10. The method of claim 8, comprising receiving a second object for caching, and not storing the second object to the cache responsive to determining a size of the second object is less than the second threshold object size.

11. The method of claim 1, comprising establishing a size of memory used by the cache for indexing objects stored to the storage of the cache.

12. The method of claim 11, comprising maintaining the size of memory used by the cache for indexing objects responsive to a change in the size of the storage used by the cache.

39. The method of claim 3 8, wherein the cache comprises a third portion of the storage established for storing objects larger than the second threshold object size.

13. A method of storing objects in a cache using multiple storage tiers based on size of objects and storing objects larger than an object threshold size to a portion of storage used by the cache, the method comprising the steps of:

(a) establishing a predetermined size for a first portion of storage used by a cache for storing objects larger than a first threshold object size, the cache storing objects smaller than the first threshold object size to a remaining portion of storage used by the cache;

(b) receiving an object for caching;

(c) determining a size of the object is greater than a first threshold object size; and

(d) storing the object in the first portion of storage responsive to the determination.

14. The method of claim 13, comprising maintaining a number of objects the cache is allowed to store to the remaining portion of the storage below a predetermined threshold.

15. The method of claim 14, comprising determining the number of objects stored to the remaining portion of the storage has reached the predetermined threshold and not storing a second received object smaller than the first threshold object size to the remaining portion of the storage.

16. The method of claim 13, comprising receiving a second object, and determining a size of the second object is less than the first threshold object size.

17. The method of claim 16, comprising storing the second object to the remaining portion of storage used by the cache if space is available to store the second object.

18. The method of claim 16, comprising determining the remaining portion of storage used by the cache does not have space available to store the second object.

19. The method of claim 18, comprising not storing the second object to the cache.

20. The method of claim 18, comprising removing a previously cached object from the remaining portion of storage used by cache and storing the second object in the remaining portion of storage.

21. The method of claim 13, comprising establishing a second predetermined size for the remaining portion of the storage used by the cache to store objects smaller than the first threshold object size.

22. The method of claim 13, comprising determining the available space of first portion of storage used by the cache is one of at or near the predetermined size, and increasing the predetermined size of the first portion of storage by allocating space from the remaining portion of storage to the first portion of storage.

23. The method of claim 13, comprising establishing a size of memory used by a cache for holding indexes to objects stored to a storage.

24. The method of claim 23, comprising maintaining the size of memory used by the cache for indexing objects responsive to a change in the size of the first portion of storage used by the cache.

25. A method of managing a size of objects stored in a cache using multiple storage tiers based on size of objects, the method maintaining a size of memory used by the cache for holding object indexes while changing a size of storage used by the cache for storing objects indexed by the object index, the method comprising the steps of:

(a) establishing a size of memory used by a cache for holding indexes to objects stored to a storage, the storage having a storage size, the cache using a first portion of the storage established for storing objects smaller than or equal to a first threshold object size and a second portion of the storage established for storing objects larger than the first threshold object size;

(b) identifying a number of objects the cache is allowed to store to the first portion of the storage;

(c) changing the size of the storage used by the cache for storing objects while maintaining the size of memory of the cache for storing indexes to the objects; and

(d) maintaining the number of objects the cache is allowed to store to the first portion of the storage below a predetermined threshold in response to changing the size of the storage used by the cache.

26. The method of claim 25, wherein step (c) comprises one of increasing or decreasing the size of the storage used by the cache for storing objects.

27. The method of claim 26, comprising changing a size of the storage device providing the storage used by the cache.

28. The method of claim 26, comprising maintaining the size of the storage device providing the storage used by the cache.

29. The method of claim 26, comprising increasing the size of the storage by adding a storage device for use by the cache.

30. The method of claim 26, comprising decreasing the size of the storage by removing a storage device used by the cache.

31. The method of claim 25, wherein step (c) comprises a user setting the size of the storage used by the cache.

32. The method of claim 25, comprising increasing a second number of objects stored to the second portion of the storage while maintaining the size of memory of the cache for storing indexes to the objects.

33. The method of claim 25, comprising keeping the number of objects the cache is allowed to store to the first portion of the storage the same in response to changing the size of the storage used by the cache.

34. The method of claim 25, comprising adjusting the number of objects the cache is allowed to store to the first portion of the storage in response to changing the size of the storage used by the cache.

35. The method of claim 25, comprising adjusting the number of objects the cache is allowed to store to the first portion of the disk relative to an amount of changing the size of the storage used by the cache.

36. The method of claim 25, comprising adjusting the number of objects the cache is allowed to store to the first portion of the storage in proportion to an amount of changing the size of the storage used by the cache.

37. The method of claim 25, comprising increasing the number of objects the cache is allowed to store to the first portion of the storage to an amount one of at or near the predetermined threshold.

38. The method of claim 25, comprising establishing a second threshold object size for objects the cache is allowed to store to the second portion of the storage, the second threshold object size greater than the first threshold object size.

40. The method of claim 38, comprising adjusting the second threshold object size in response to changing the size of the storage used by the cache.

41. The method of claim 25, comprising establishing a second number of objects the cache is allowed to store to the second portion of the storage.

42. The method of claim 41, comprising adjusting the second number of objects the cache is allowed to store to the second portion of the storage in response to changing the size of the storage used by the cache.

43. The method of claim 41, comprising maintaining the second number of objects the cache is allowed to store to the second portion of the storage within a second predetermined threshold in response to changing the size of the storage used by the cache.

44. A method of managing a size of objects stored in a cache using multiple storage tiers based on size of objects, the method changing a size of memory used by the cache for holding object indexes while maintaining a size of storage used by the cache for storing objects indexed by the object index, the method comprising the steps of:

(a) establishing a size of memory used by a cache for holding indexes to objects stored to a storage, the storage having a storage size, the cache using a first portion of the storage for storing objects smaller than or equal to a first threshold object size and a second portion of the storage for storing objects larger than the first threshold object size;

(b) identifying a number of objects the cache is allowed to store to the first portion of the storage;

(c) changing the size of memory used by the cache for holding object indexes while maintaining the size of storage used by the cache for storing objects; and

(d) maintaining the number of objects the cache is allowed to store to the first portion of the storage below a predetermined threshold in response to changing the size of the memory used by the cache.

45. The method of claim 44, wherein step (c) comprises one of increasing or decreasing the size of the memory used by the cache.

46. The method of claim 44, comprising changing a size of the memory element providing the memory used by the cache.

47. The method of claim 44, comprising maintaining the size of the memory element providing the memory used by the cache.

48. The method of claim 44, comprising increasing the size of the memory by adding a memory element for use by the cache.

49. The method of claim 44, comprising decreasing the size of the memory by removing a memory element used by the cache.

50. The method of claim 44, wherein step (c) comprises a user setting the size of the memory used by the cache.

51. The method of claim 44, comprising adjusting the number of objects stored to the first portion of the storage while maintaining the size of storage of the cache for storing objects.

52. The method of claim 44, comprising keeping the number of objects the cache is allowed to store to the first portion of the storage the same in response to changing the size of the memory used by the cache.

53. The method of claim 44, comprising adjusting the number of objects the cache is allowed to store to the first portion of the storage relative to an amount of change to the size of the memory used by the cache.

54. The method of claim 44, comprising increasing the number of objects the cache is allowed to store to the first portion of the storage to an amount one of at or near the predetermined threshold.

55. The method of claim 44, comprising establishing a second threshold object size for objects the cache is allowed to store to the second portion of the storage, the second threshold object size greater than the first threshold object size.

56. The method of claim 55, wherein the cache comprises a third portion of the storage established for storing objects larger than the second threshold object size.

57. The method of claim 55, comprising adjusting the second threshold object size in response to changing the size of the memory used by the cache.

58. The method of claim 57, comprising establishing a second number of objects the cache is allowed to store to the second portion of the storage.

59. The method of claim 58, comprising adjusting the second number of objects the cache is allowed to store to the second portion of the storage in response to changing the size of the memory used by the cache.

60. The method of claim 58, comprising maintaining the second number of objects the cache is allowed to store to the second portion of the storage within a second predetermined threshold in response to changing the size of the memory used by the cache.

61. A method of managing a size of objects stored in a cache using multiple storage tiers based on size of objects, the method allocating a portion of storage used by the cache for storing larger objects, the method comprising the steps of:

(a) establishing a size of memory used by a cache for holding indexes to objects stored to a storage, the storage having a storage size;

(b) establishing a first predetermined size of a first portion of a storage of a cache for storing objects larger than a first threshold object size, the cache using a second portion of the storage of the cache to store objects smaller than the first threshold object size;

(c) changing one of the size of memory or the storage size used by the cache; and

(d) maintaining the first predetermined size of the first portion of the storage of the cache in response to changing one of the size of memory or the storage size used by the cache.

62. The method of claim 61, wherein step (c) comprises one of increasing or decreasing the storage size used by the cache for storing objects.

63. The method of claim 61, wherein step (c) comprises one of increasing or decreasing the size of the memory used by the cache for indexing objects.

64. The method of claim 61, comprising identifying a number of objects the cache is allowed to store to the first portion of the storage.

65. The method of claim 64, comprising maintaining the number of objects the cache is allowed to store to the first portion of the storage in response to changing one of the size of memory or the storage size used by the cache.

66. The method of claim 61, comprising adjusting the first threshold object size in response to changing one of the size of memory or the storage size used by the cache.

67. The method of claim 61, comprising adjusting a number of objects the cache is allowed to store to the second portion of the storage while maintaining the first predetermined size of the first portion of the storage.

68. The method of claim 61, comprising adjusting the number of objects the cache is allowed to store to the first portion of the storage in response to changing one of the size of the memory or the storage size used by the cache.

69. The method of claim 61, comprising adjusting the number of objects the cache is allowed to store to the second portion of the disk relative to an amount of change to one of the size of the memory or the storage size used by the cache.

70. The method of claim 61, comprising establishing a second threshold object size for objects the cache is allowed to store to the second portion of the storage, the second threshold object size smaller than the first threshold object size.

71. The method of claim 70, wherein the cache comprises a third portion of the storage established for storing objects smaller than the second threshold object size.

72. The method of claim 72, comprising adjusting the second threshold object size in response to changing one of the size of memory or the storage size used by the cache.