Systems and methods of providing a multi-tier cache

• US 8,074,028 B2
• Filed: 03/12/2007
• Issued: 12/06/2011
• 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
• Primary Examiner(s): Bragdon, Reginald
• Assistant Examiner(s): AHMED, HAMDY S
• Application Number:
  US11/685,130
• Publication Number:
  US 20080229020A1
• Time in Patent Office: 1,730 Days
• Field of Search: 711/122
• US Class Current: 711/129
• 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 multi-tiered caching and cache indexing system is depicted. A cache management system uses a memory based object index to reference or identify corresponding objects stored in disk. The memory used to index object may grow proportionally or in relation to growth in the size of the disk. The techniques described herein minimize, reduce or maintain the size of memory for an object index although the size of storage for storing objects is changed. These techniques allow for more optimal use of memory for object indexing while increasing or decreasing disk size for object storage.

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:

(a) establishing, by a cache manager executing on a device, a fixed size of a storage for a cache to store cached objects communicated via network traffic and a plurality of tiers across the fixed size of the storage, the plurality of tiers comprising a first tier of storage for storing objects smaller than or equal to a first threshold object size and a second tier of storage for storing objects larger than the first threshold object size;

(b) identifying, by the cache manager, a maximum number of objects the cache is allowed to store to the first tier of storage, the cache manager allocating a portion of the fixed size of the storage to the first tier of storage based on the maximum number of objects multiplied by the first threshold object size;

(c) receiving, by the cache manager a request to store an object of an application for caching, the object comprising data communicated by the application via a protocol carried by a transport layer protocol;

(d) determining, by the cache manager, to store the object in one of the first tier of the storage or the second tier of the storage based on a size of the object; and

(e) maintaining, by the cache manager responsive to changing the predetermined size of the storage for the cache and while increasing the second tier'"'"'s size, the number of objects the cache is allowed to store to the first tier of 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 tier of 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 tier of storage.

4. The method of claim 1, comprising determining the number of objects stored to the first tier of 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 tier of 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 tier of 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 tier 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 tier of storage.

9. The method of claim 8, comprising receiving a second object for caching, and storing the second object in the first tier of 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 fixed 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 fixed size of memory used by the cache for indexing objects responsive to a change in the fixed size of the storage used by the cache.

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:

(a) establishing, by a cache manager executing on a device, a cache with a plurality of tiers across a fixed storage size, the plurality of tiers comprising a first tier of storage having a first predetermined size used by\ the cache for storing objects larger than a first threshold object size and a second tier of storage having a second predetermined size for storing objects smaller than the first threshold object size, the objects communicated via network traffic;

(b) receiving, by a network optimization engine, a request to store an object of an application for caching, the object comprising data communicated by the application via a protocol carried by a transport layer protocol;

(c) determining, by the cache manager, a size of the object is greater than a first threshold object size;

(d) storing, by the cache manager, the object in the first tier of storage responsive to the determination; and

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

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

15. The method of claim 14, comprising determining the number of objects stored to the second tier of has reached the predetermined threshold and not storing a second received object smaller than the first threshold object size to the second tier of 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 second tier of storage used by the cache if space is available to store the second object.

18. The method of claim 16, comprising determining the second tier 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 second tier of used by cache and storing the second object in the second tier of storage.

21. The method of claim 13, comprising establishing a second predetermined size for the second tier of 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 tier 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 second tier of storage to the first tier of storage.

23. The method of claim 13, comprising establishing a fixed 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 fixed size of memory used by the cache for indexing objects responsive to a change in the size of the first tier 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:

(a) establishing, by a cache manager executing on a device, a predetermined size of memory used by a cache for holding indexes to objects communicated by applications via network traffic, the objects of the applications stored to a storage, the storage having a predetermined storage size, the cache comprising a plurality of tiers across the predetermined storage size, the plurality of tiers comprising a first tier of storage established for storing objects smaller than or equal to a first threshold object size and a second tier of storage established for storing objects larger than the first threshold object size;

(b) identifying, by the cache manager, a number of objects the cache is allowed to store to the first tier of the storage;

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

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

26. The method of claim 25, wherein step (c) comprises one of increasing or decreasing the predetermined 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 predetermined 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 tier of 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 tier of storage the same in response to changing the predetermined 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 tier of storage in response to changing the predetermined 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 predetermined 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 tier of storage in proportion to an amount of changing the predetermined 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 predetermined 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 tier of storage, the second threshold object size greater than the first threshold object size.

39. The method of claim 38, wherein the cache comprises a third tier of storage established for storing objects larger than the second threshold object size.

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

42. The method of claim 41, comprising adjusting the second number of objects the cache is allowed to store to the second tier of storage in response to changing the predetermined 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 tier of storage within a second predetermined threshold in response to changing the predetermined 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, by a cache manager executing on a device, a predetermined size of memory used by a cache for holding indexes to objects communicated by applications via network traffic, the objects of the applications stored to a storage, the storage having a predetermined storage size, the cache comprising a plurality of tiers across the predetermined storage size, the plurality of tiers comprising a first tier of storage for storing objects smaller than or equal to a first threshold object size and a second tier of storage for storing objects larger than the first threshold object size;

(b) identifying, by the cache manager, a number of objects the cache is allowed to store to the first tier of storage;

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

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

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

51. The method of claim 44, comprising adjusting the number of objects stored to the first tier of the storage while maintaining the predetermined 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 tier of storage the same in response to changing the predetermined 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 tier of storage relative to an amount of change to the predetermined 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 tier of 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 tier of 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 tier of 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 predetermined 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 tier of storage.

59. The method of claim 58, comprising adjusting the second number of objects the cache is allowed to store to the second tier of storage in response to changing the predetermined 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 tier of storage within a second predetermined threshold in response to changing the predetermined 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, by a cache manager executing on a device, a fixed size of memory used by a cache for holding indexes to objects of applications stored to a storage, the storage having a fixed storage size, the objects communicated via an application layer protocol;

(b) establishing, by the cache manager, a cache comprising a plurality of tiers across the fixed storage size, the plurality of tiers comprising a first predetermined size of a first tier of the cache for storing objects of applications larger than a first threshold object size, the cache using a second tier of storage of the cache to store objects smaller than the first threshold object size;

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

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

62. The method of claim 61, wherein step (c) comprises one of increasing or decreasing the fixed 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 fixed 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 tier of storage.

65. The method of claim 64, comprising maintaining the number of objects the cache is allowed to store to the first tier of storage in response to changing one of the fixed size of memory or the fixed 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 fixed size of memory or the fixed 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 tier of storage while maintaining the first predetermined size of the first tier of storage.

68. The method of claim 61, comprising adjusting the number of objects the cache is allowed to store to the first tier of storage in response to changing one of the fixed size of the memory or the fixed 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 fixed size of the memory or the fixed 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 tier of 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 tier of storage established for storing objects smaller than the second threshold object size.

72. The method of claim 70, comprising adjusting the second threshold object size in response to changing one of the fixed size of memory or the fixed storage size used by the cache.