Methods and Systems for Caching Content at Multiple Levels

• US 20070245090A1
• Filed: 03/23/2007
• Published: 10/18/2007
• Est. Priority Date: 03/24/2006
• Status: Active Grant

• Current Assignee: CA, Inc. (d/b/a CA Technologies) (Broadcom, Inc.)
• Original Assignee: Blue Coat Systems Incorporated (Gen Digital Inc.)
• Inventors: Mahdavi, Jamshid, King, Chris, Duvvuri, Ravikumar, Mullaney, Steve
• Granted Patent: US 8,832,247 B2
• Time in Patent Office: Days
• US Class Current: 711/129
• CPC Class Codes: G06F 12/0813 with a network or matrix configuration
• CPC Class Codes: G06F 12/0875 with dedicated cache, e.g. instruction or stack
• CPC Class Codes: G06F 12/0897 with two or more cache hierarchy levels with multilevel cache hierarchies G06F12/0811
• CPC Class Codes: G06F 2212/154 Networked environment
• 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 67/568 Storing data temporarily at an intermediate stage, e.g. caching
• CPC Class Codes: H04L 67/5682 Policies or rules for updating, deleting or replacing the stored data

Abstract

A cache includes an object cache layer and a byte cache layer, each configured to store information to storage devices included in the cache appliance. An application proxy layer may also be included. In addition, the object cache layer may be configured to identify content that should not be cached by the byte cache layer, which itself may be configured to compress contents of the object cache layer. In some cases the contents of the byte cache layer may be stored as objects within the object cache.

Claims

1. A cache, comprising an object cache layer and a byte cache layer, each configured to store information to storage devices included in the cache.

2. The cache of claim 1, wherein the object cache layer and the byte cache layer are configured to communicate with one another through a socketpair.

3. The cache of claim 1, further including an application proxy layer configured to identify content that should not be cached by one or more of the object cache layer and the byte cache layer.

4. The cache of claim 3, wherein the application proxy layer is configured to pass content not cacheable at the object cache layer to the byte cache layer.

5. The cache of claim 1, wherein the byte cache layer is configured to compress contents of the object cache layer.

6. The cache of claim 5, wherein the object cache layer enables or disables compression at the byte cache layer based on whether content is known to be compressible or not compressible.

7. The cache of claim 6, further comprising an application proxy layer configured to determine whether the content is compressible or not compressible.

8. The cache of claim 1, wherein contents of the byte cache layer are stored as objects within the object cache.

9. A method, comprising receiving content from a content source and caching said content first at an object cache layer of a cache and next at a byte cache layer of the cache so as to eliminate repeated strings present within the content after caching at the object cache layer.

10. The method of claim 9, further comprising prior to caching said content at the object cache layer, transforming the content from a first format to a second format.

11. The method of claim 10, wherein said first format comprises an encrypted data format and said second format comprises a decrypted data format.

12. The method of claim 9 further comprising prior to caching said content at the object cache layer, examining said content for compliance with one or more policies.

13. The method of claim 12 wherein said one or more policies include policy checking performed remotely from the cache.

14. The method of claim 9, further comprising prior to compressing said content at the byte cache layer, said content is transformed from a first format to a second format.

15. The method of claim 9, further comprising intra-stream compressing an output of the byte cache layer.

16. The method of claim 15, further comprising transforming intra-stream compressed output of the byte cache layer from a first data format to a second data format.

17. The method of claim 16, wherein the first data format comprises an unencrypted data format and the second data format comprises an encrypted data format.

18. A method, comprising receiving content from a content source, decompressing said content at a byte cache layer to produce expanded content, and transmitting said expanded content to a client along with previously cached objects from an object cache layer, wherein said byte cache layer and said object cache layer are included in a common cache.

19. The method of claim 18, further comprising caching the expanded content at the object cache layer.

20. The method of claim 18, further comprising prior to decompressing said content at the byte cache layer transforming the content from a first data format to a second data format.

21. The method of claim 20, wherein the first data format comprises an encrypted data format and the second data format comprises a decrypted data format.

22. The method of claim 20, wherein the first data format comprises an encrypted and compressed data format and the second data format comprises a decrypted and decompressed data format.

23. The method of claim 19, further comprising transforming the expanded content and previously cached objects from a first data format to a second data format.

24. The method of claim 23, wherein the first data format comprises a decrypted data format and the second data format comprises an encrypted data format.

25. A system comprising a first object cache communicatively coupled to a second object cache via a transport and signaling channel comprising reciprocal byte cache layers.

26. The system of claim 25, further comprising an application proxy layer distributed between platforms supporting the first and second object cache.

27. The system of claim 25 wherein the first object cache is instantiated in a cache appliance.

28. The system of claim 25, wherein the first object cache is instantiated as a thin client executing on a computer platform.

29. The system of claim 25 wherein the second object cache is instantiated in a cache appliance.

30. The system of claim 25, wherein the second object cache is instantiated as a thin client executing on a computer platform.

31. The system of claim 25, wherein policy-based decisions are implemented at an application proxy layer associated with one or more of the first object cache and the second object cache.

32. The system of claim 31, wherein the policy-based decisions are based on one or more of configured policy information, heuristics or other algorithms.

33. The system of claim 31, wherein the policy-based decisions include decisions concerning what information is or is not cached at the reciprocal byte cache level.

34. The system of claim 31, wherein the policy-based decisions include decisions concerning personally identifying information of a user.

35. The system of claim 25, wherein the byte cache layers are configured to compress and decompress contents of at least one of the object caches.

36. The system of claim 25, wherein the reciprocal byte cache layers include a thinning mechanism whereby less popular data stored in the byte cache layers are removed over time.

37. The system of claim 25, wherein the reciprocal byte cache layers are configured to store byte patterns of only less than a threshold size.

38. The system of claim 25, wherein the first object cache is configured to store data transmitted from a client to a server during a write operation.

39. A cache, comprising a multi-level caching architecture in which content received from a content source is cached at multiple protocol stack levels according to its cacheability at each such layer.

40. The system of claim 39, wherein the byte cache layers of each of the first and second cache store common strings with their respective tokens.