Distributed cache between servers of a network

• US 20040111486A1
• Filed: 12/06/2002
• Published: 06/10/2004
• Est. Priority Date: 12/06/2002
• Status: Active Grant

• Current Assignee: Scott Ruple
• Original Assignee: Scott Ruple
• Inventors: Volden, Tom, Hawkinson, Chris, Ruple, Scott, Schuh, Karl
• Granted Patent: US 7,254,617 B2
• Time in Patent Office: Days
• US Class Current: 709/214
• CPC Class Codes: G06F 16/9574 of access to content, e.g. by caching

Abstract

A distributed cache module that allows for a distributed cache between multiple servers of a network without using a central cache manager. The distributed cache module transmits each message with a logical timestamp. The distributed cache module of a server that receives the message will delay forwarding of the message to, for example, a client computer, if preceding timestamps are not received. This insures a correct order of timestamped messages without requiring a central manager to allocate and control the transmission of the messages within the network. Each distributed cache module will request and possibly retrieve data from the cache of another server in response to a file request for the data. The data of a file may be accessed by a plurality of servers joined in a file context.

Claims

1. A distributed cache system that includes a first server that has a first cache and a second server that has a second cache, comprising:

a first distributed cache module that resides in the first server and transfers a message and a logical timestamp; and

,

a second distributed cache module that resides in the second server and receives the message, said second distributed cache module delays a transfer of the message if said second server has not received all preceding logical timestamps.

2. The system of claim 1, wherein said first distributed cache module has a cookie.

3. The system of claim 1, wherein said first and second distributed cache modules each have a unique member ID in a context.

4. The system of claim 1, wherein said first distributed cache module assigns its own unique member ID.

5. The system of claim 1, wherein said first distributed cache module contains a prediction of a location of data in said second cache of said second server.

6. The system of claim 1, wherein said logical timestamp includes an n array where n is equal to a number of servers in a file context.

7. A network, comprising:

a first server that includes a first cache and a first distributed cache module, said first distributed cache module transfers a message and a logical timestamp; and

,

a second server that includes a second cache and a second distributed cache module, said second distributed cache module receives the message and delays the transfer of the message if said second server has not received all preceding logical timestamps.

8. The network of claim 7, wherein said first distributed cache module has a cookie.

9. The network of claim 7, wherein said first and second distributed cache modules each have a unique member ID for a context.

10. The network of claim 7, wherein said first distributed cache module assigned its own unique member ID.

11. The network of claim 7, wherein said first distributed cache module contains a prediction of a location of data in said second cache of said second server.

12. The network of claim 7, wherein said logical timestamp includes an n array where n is equal to a number of servers in a context.

13. The network of claim 7, further comprising a rogue server and a network attached storage, said first and second distributed cache modules verify a file before transferring a file from said network attached storage.

14. The network of claim 7, wherein said first cache includes a first file block and said second cache includes a second file block, said first distributed cache module requests and retrieves said second file block from said second cache.

15. A method for transferring a message between a first server that has a first cache and a second server that has a second cache, comprising:

transmitting a message and a logical timestamp from the first server;

receiving the message at the second server;

determining whether the second server has received all preceding logical timestamps; and

,

delaying a transfer of the message if the second server has not received all preceding logical timestamps.

16. The method of claim 15, wherein the first server has a cookie.

17. The method of claim 15, further comprising transmitting from the first server a message with a self assigned member ID to enter a context.

18. The method of claim 17, further comprising transmitting from the second server to the first server a NACK message with a suggested member ID.

19. The method of claim 17, further comprising transmitting from the second server an ACK message and member IDs for every server in a context.

20. The method of claim 15, wherein the second server requests and retrieves a data file block located in the first cache of the first server.

21. A distributed cache module for a system that includes a first server that has a first cache and a second server that has a second cache, the second cache containing a file block, comprising:

a first distributed cache module that resides in the first server, said first distributed cache module requests and receives the file block from the second cache of the second server.

22. The module of claim 21, further comprising a second distributed cache module that resides in the second server, wherein said first distributed cache module has a cookie.

23. The module of claim 22, wherein said first and second distributed cache modules each have a unique member ID in a context.

24. The module of claim 23, wherein said first distributed cache module assigns its own unique member ID.

25. The module of claim 22, wherein said first distributed cache module contains a prediction of a location of the file block in the second cache of the second server.

26. A network, comprising:

a first server that includes a first cache and a first distributed cache module, said first cache contains a file block; and

,

a second server that includes a second cache and a second distributed cache module, said second distributed cache module requests and retrieves the file block from said second cache of said second server.

27. The network of claim 26, wherein said first distributed cache module has a cookie.

28. The network of claim 26, wherein said first and second distributed cache modules each have a unique member ID in a context.

29. The network of claim 26, wherein said first distributed cache module assigns its own unique member ID.

30. The network of claim 26, wherein said first distributed cache module contains a prediction of a location of the file block in the first cache of the first server.

31. The network of claim 26, further comprising a rogue server and a network attached storage, said first and second distributed cache modules verify a file before transferring a file from said network attached storage.

32. A method for transferring a message between a first server that has a first cache and a second server that has a second cache, the second cache containing a file block, comprising:

receiving a request for the file block by the first server;

transmitting a request for the file block from the first server to the second server; and

,

transferring the file block from the second server to the first server.

33. The method of claim 32, wherein the first server has a cookie.

34. The method of claim 32, further comprising transmitting from the first server a message with a self assigned member ID to enter a context.

35. The method of claim 34, further comprising transmitting from the second server to the first server a NACK message with a suggested member ID.

36. The method of claim 34, further comprising transmitting from the second server an ACK message and member IDs for every server in a context.

37. A distributed cache module for a system that includes a first server that has a first cache and a second server that has a second cache, comprising:

a first distributed cache module that resides in the first server, said first distributed cache module receives a file request and generates a join message to join a context relating to the file request.

38. The module of claim 37, further comprising a second distributed cache module that resides in the second server, wherein said first distributed cache module has a cookie.

39. The module of claim 37, wherein said first and second distributed cache modules each have a unique member ID in the context.

40. The module of claim 39, wherein said first distributed cache module assigns its own unique member ID that is transmitted with the join message.

41. The module of claim 38, wherein said first distributed cache module contains a prediction of a location of data in the second cache of the second server.

42. A network, comprising:

a first server that includes a first cache and a first distributed cache module, said first server receives a file request and generates a join message to join a context relating to the file request; and

,

a second server that includes a second cache and a second distributed cache module, said second distributed cache module receives the join message and transmits an ACK message to said first server.

43. The network of claim 42, wherein said first distributed cache module has a cookie.

44. The network of claim 42, wherein said first and second distributed cache modules each have a unique member ID in the context.

45. The network of claim 44, wherein said first distributed cache module assigns its own unique member ID that is transmitted with the join message.

46. The network of claim 45, wherein said second server transmits a NACK message with a suggested member ID.

47. The network of claim 45, wherein said second server transmits an ACK message and member IDs for each server joined in the context.

48. A method for establishing a distributed cache between a first server that has a first cache and a second server that has a second cache, comprising:

receiving a file request by the first server;

broadcasting a join request message to join a file context relating to the file request; and

,

joining the file context.

49. The method of claim 48, wherein the first server has a cookie.

50. The method of claim 48, further comprising transmitting from the first server a self assigned member ID with the join message.

51. The method of claim 48, further comprising transmitting from the second server to the first server a NACK message with a suggested member ID.

52. The method of claim 48, further comprising transmitting from the second server to the first server an ACK message with member IDs of other servers in the file context.