TOPOLOGY AWARE CACHE COOPERATION

• US 20100217869A1
• Filed: 08/31/2009
• Published: 08/26/2010
• Est. Priority Date: 02/20/2009
• Status: Active Grant

• Current Assignee: Alcatel-Lucent SA (Nokia Corporation)
• Original Assignee: Alcatel-Lucent SA (Nokia Corporation)
• Inventors: Rimac, Ivica, Hilt, Volker, Beck, Andre, Esteban, Jairo O.
• Granted Patent: US 8,417,816 B2
• Time in Patent Office: Days
• US Class Current: 709/226
• CPC Class Codes: G06F 16/185 Hierarchical storage management [HSM] systems, e.g. file migration or policies thereof details of archiving G06F16/11
• CPC Class Codes: G06F 16/40 of multimedia data, e.g. slideshows comprising image and additional audio data retrieval of still image data G06F16/50; retrieval of audio data G06F16/60; retrieval of video data G06F16/70
• CPC Class Codes: H04L 67/568 Storing data temporarily at an intermediate stage, e.g. caching

Abstract

A content distribution network (CDN) comprising a hierarchy of content storage nodes (CSNs) or caches having storage space that is allocated between local space for storing locally popular content objects and federated space for storing a portion of the less popular content objects. Local space and federated space based upon changes in content object popularity and/or other utility factors. Optionally, parent/child (upstream/downstream) communication paths are used to migrate content between CSNs or caches of the same or different hierarchical levels to avoid utilizing higher price top hierarchical level communications channels.

Claims

1. A content distribution system (CDS) for distributing a plurality of available content objects, comprising:

a plurality of content storage nodes (CSNs), each CSN comprising a network node adapted for communication with at least one other network node and a storage device having a first memory portion allocated to local space and a second memory portion allocated to federated space;

wherein

the local space of each CSN is adapted to store available content objects having a relatively high utility level;

the federated space of each CSN is adapted to cooperate with the federated space of other CSNs to store at least a portion of available content objects having a relatively low utility level; and

content objects are migrated between local space and federated space in response to differences in content object utility level.

2. The CDS of claim 1, wherein:

each of a plurality of lowest hierarchical level CSNs is associated with a subnetwork adapted to communicate with client devices; and

each lowest hierarchical level CSN preferentially stores in its local space those content objects most requested via its respective subnetwork.

3. The CDS of claim 2, wherein each lowest hierarchical level CSN preferentially stores in its federated space those content objects that are demoted from its local space.

4. The CDS of claim 2, wherein each lowest hierarchical level CSN preferentially stores in a virtual federated space those content objects that are demoted from its local space, the virtual federated space formed by logically combining the federated space of each CSN.

5. The CDS of claim 2, wherein a group of lowest hierarchical level CSNs receives content objects via respective communication paths with a common parent CSN, wherein content objects are moved between members of the group of lowest hierarchical level CSNs via the common parent CSN.

6. The CDS of claim 5, wherein each of a plurality of parent CSNs receives content objects via respective communication paths with an upper hierarchical level CSN, wherein content objects are moved between the plurality of parent CSNs via the upper hierarchical level CSN.

7. The CDS of claim 1, further comprising a content aggregation node for distributing content objects to at least one top hierarchical level CSN via a high bandwidth communications channel.

8. The CDS of claim 7, further comprising a content vault for storing content objects for distribution via the content aggregation node.

9. The CDS of claim 1, wherein the CDS comprises at least two top hierarchical level CSNs in communication with each other via a peer-to-peer communications channel, each top hierarchical level CSN having associated with it a respective group of lower hierarchical level CSNs, wherein content objects are moved between the respective lower hierarchical level CSN groups via the peer-to-peer communications channel.

10. The CDS of claim 1, wherein the CDS comprises at least one peer-to-peer communication channel linking CSNs of the same hierarchical level, wherein content objects are moved between lower hierarchical level CSN groups via the peer-to-peer communication channel.

11. The CDS of claim 1, wherein:

a first upper hierarchical level CSN is associated with a first group of lower hierarchical level CSNs;

a second upper hierarchical level CSN is associate with a second group of lower hierarchical level CSNs;

wherein

content objects are moved between the first upper hierarchical level CSN and a CSN of the second group of lower hierarchical level CSNs via an inter-level communication channel.

12. The CDS system of claim 1, further comprising a content manager adapted to manage federated space allocations within CSN storage devices.

13. The CDS of claim 12, wherein the content manager adapts local space and federated space allocations in response to changes in content object popularity.

14. The CDS of claim 12, wherein said content manager adapts local space and federated space allocations in response to changes in at least one of network bandwidth cost and storage device cost.

15. The CDS of claim 1, wherein:

the CDS comprises a hierarchical topology supporting parent-child communications; and

local space and federal space allocations are adapted in a manner tending to increase reverse channel bandwidth utilization.

16. The CDS of claim 15, further comprising at least one intra-level communications link.

17. The CDS of claim 15, further comprising at least one inter-level communications link.

18. The CDS of claim 1, wherein in response to a request for a content object not stored in a CSN, the requested content object replaces one or more less popular content objects presently stored in a local space of the CSN.

19. The CDS of claim 18, wherein if the requested content object is less popular than the content objects presently stored in the local space of the CSN, and the requested content object is stored in federated space less than a threshold number of times, the requested content object replaces one or more less popular content objects presently stored in federated space.

20. In a content distribution system (CDS) comprising a plurality of content storage nodes (CSNs), each CSN including a storage device allocated between a local space and a federated space, a method for adapting the storage of content, comprising:

receiving a content object request at a CSN;

replacing a content object stored in local space of the CSN with the requested content object if a utility level of the content object stored in local space is less than a utility level of the requested content object;

replacing a content object stored in federated space with the requested content object if a utility level of the content object stored in federated space is less than the utility level of the requested content object and the requested content object does not replace a content object stored in local space;

replacing a content object stored in federated space with the replaced local space content object if the utility level of the content object stored in federated space is less than the utility level of the replaced local space content object.

21. The method of claim 20, wherein replacing a content object stored in federated space comprises transmitting the replacement content object toward the CSN storing the content object to be replaced.

22. The method of claim 21, wherein the replacement content object is transmitted via a parent CSN.

23. The method of claim 20, further comprising adapting the relative allocation of local space and federated space within at least one CSN in response to at least one of network bandwidth cost and storage cost.

24. A computer readable medium storing a software program that, when executed by a computer, causes the computer to perform a method for adapting the storage of content, the method comprising:

receiving a content object request at a content storage node (CSN) within a content distribution system (CDS) comprising a plurality of CSNs, each CSN including a storage device allocated between a local space and a federated space;

replacing a content object stored in local space of the CSN with the requested content object if a utility level of the content object stored in local space is less than a utility level of the requested content object;

replacing a content object stored in federated space with the requested content object if a utility level of the content object stored in federated space is less than the utility level of the requested content object and the requested content object does not replace a content object stored in local space;

replacing a content object stored in federated space with the replaced local space content object if the utility level of the content object stored in federated space is less than the utility level of the replaced local space content object.