Method and System for Dynamic Distributed Data Caching

• US 20070150575A1
• Filed: 03/02/2007
• Published: 06/28/2007
• Est. Priority Date: 01/12/2001
• Status: Active Grant

• Current Assignee: Parallel Networks, LLC (epicRealm Licensing LP)
• Original Assignee: Epicrealm Operating Inc.
• Inventors: Chin, Bryan, Lowery, Keith, Consolver, David, DeMasters, Gregg
• Granted Patent: US 7,694,076 B2
• Time in Patent Office: Days
• US Class Current: 709/223
• CPC Class Codes: G06F 16/9537 Spatial or temporal dependent retrieval, e.g. spatiotemporal queries
• CPC Class Codes: G06F 16/9574 of access to content, e.g. by caching
• CPC Class Codes: H04L 43/16 Threshold monitoring
• CPC Class Codes: H04L 67/01 Protocols
• CPC Class Codes: H04L 67/104 Peer-to-peer [P2P] networks
• CPC Class Codes: H04L 67/1046 Joining mechanisms
• CPC Class Codes: H04L 67/1048 Departure or maintenance mechanisms
• CPC Class Codes: H04L 67/1068 Discovery involving direct consultation or announcement among potential requesting and potential source peers
• CPC Class Codes: H04L 67/108 characterised by resources being split in blocks or fragments
• CPC Class Codes: H04L 67/1097 for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS]
• CPC Class Codes: H04L 67/568 Storing data temporarily at an intermediate stage, e.g. caching

Abstract

A method and system for dynamic distributed data caching is presented. The method includes providing a cache community (402) comprising at least one peer (413). Each peer has an associated first content portion (511) indicating content to be cached by the respective peer. A client (404) may be allowed to join the cache community. A peer list (426) associated with the cache community is updated to include the client. The peer list indicates the peers in the cache community. A respective second content portion (511) is associated with each peer based on the addition of the client.

Claims

1. A method for dynamic distributed data caching, comprising:

determining that a first master associated with a cache community is non-operational;

electing a second master from peer members in the cache community to replace the first master; and

allocating at least one content portion among the peer members in the cache community based on the loss of the first master.

2. The method of claim 1, wherein determining that the first master is non-operational includes:

determining the amount of time since a member status request message has been received;

determining whether the amount of time exceeds a threshold.

3. The method of claim 2, wherein the member status request message includes CRMSG_PEERPING data message.

4. The method of claim 2, wherein the threshold includes a predetermined time.

5. The method of to claim 1, wherein electing the second master includes:

communicating a hold election message to the peer members in the cache community;

receiving at least one response to the hold election message;

selecting one of the peer members to be the second master;

communicating an update master message to a cache server tracking the cache community.

6. The method of claim 5, wherein the hold election message includes a CRMSG_HOLDELECTION data message.

7. The method of claim 5, wherein electing the second master includes aborting the election if a response is received from the first master.

8. The method of claim 5, wherein the update master message includes a CRMSG_REPLACEMASTER data message.

9. The method of claim 1, wherein allocating at least one content portion includes:

allocating respective content portions to peer members in the cache community;

updating an allocation table at the second master to indicate allocation of the respective content portions associated with the respective peer members.

10. The method of claim 9, wherein the content portions are distinct.

11. A computer readable medium including code for dynamic distributed data caching, the code operable to:

determine that a first master associated with a cache community is non-operational;

elect a second master from peer members in the cache community to replace the first master; and

allocate at least one content portion among the peer members in the cache community based on the loss of the first master.

15. The computer readable medium of claim 11, wherein the code is further operable to:

communicate a hold election message to the peer members in the cache community;

receive at least one response to the hold election message;

select one of the peer members to be the second master; and

communicate an update master message to a cache server tracking the cache community.

16. The computer readable medium of claim 15, wherein the hold election message includes a CRMSG_HOLDELECTION data message.

17. The computer readable medium of claim 15, wherein the code is further operable to abort the election if a response is received from the first master.

18. The computer readable medium of claim 15, wherein the update master message includes a CRMSG_REPLACEMASTER data message.

19. The computer readable medium of claim 11, wherein the code is further operable to:

allocate respective content portions to the peer members in the cache community; and

update an allocation table at the second master to indicate allocation of the respective content portions associated with the respective peer members.

20. The computer readable medium of claim 19, wherein the content portions are distinct.

12. The computer readable medium of claim 41, wherein the code is further operable to:

determine the amount of time since a member status request message has been received; and

determine whether the amount of time exceeds a threshold.

13. The computer readable medium of claim 12, wherein the member status request message includes CRMSG_PEERPING data message.

14. The computer readable medium of claim 12, wherein the threshold includes a predetermined time.

21. A system for dynamic distributed data caching comprising:

means for determining that a first master associated with a cache community is non-operational;

means for electing a second master from peer members in the cache community to replace the first master; and

means for allocating at least one content portion among the peer members in the cache community based on the loss of the first master.

22. The method of claim 21, wherein the means for determining that the first master is non-operational includes:

means for determining the amount of time since a member status request message has been received;

means for determining whether the amount of time exceeds a threshold.

23. The method of claim 22, wherein the member status request message includes CRMSG_PEERPING data message.

24. The method of claim 22, wherein the threshold includes a predetermined time.

25. The method of to claim 21, wherein the means for electing the second master includes:

means for communicating a hold election message to the peer members in the cache community;

means for receiving at least one response to the hold election message;

means for selecting one of the peer members to be the second master;

means for communicating an update master message to a cache server tracking the cache community.

26. The method of claim 25, wherein the hold election message includes a CRMSG_HOLDELECTION data message.

27. The method of claim 25, wherein the means for electing the second master includes means for aborting the election if a response is received from the first master.

28. The method of claim 25, wherein the update master message includes a CRMSG_REPLACEMASTER data message.

29. The method of claim 21, wherein the means for allocating at least one content portion includes:

means for allocating respective content portions to peer members in the cache community;

means for updating an allocation table at the second master to indicate allocation of the respective content portions associated with the respective peer members.

30. The method of claim 29, wherein the content portions are distinct.