Representation of qualitative object changes in a knowledge based framework for a multi-master synchronization environment

• US 8,185,495 B2
• Filed: 02/01/2008
• Issued: 05/22/2012
• Est. Priority Date: 02/01/2008
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Clark, Michael Ray, Novik, Lev, Khosravy, Moe, Lee, Oliver
• Primary Examiner(s): BROWN, SHEREE N
• Application Number:
  US12/024,967
• Publication Number:
  US 20090196179A1
• Time in Patent Office: 1,572 Days
• Field of Search: 707202-203, 707609-614, 707/620
• US Class Current: 707/610
• CPC Class Codes: G06F 16/178 Techniques for file synchronisation in file systems
• CPC Class Codes: G06F 16/27 Replication, distribution or synchronisation of data between databases or within a distributed database system; Distributed database system architectures therefor
• CPC Class Codes: H04L 12/281 indicating a format for calling an appliance service function in a home automation network for remote control or remote monitoring of applications H04L67/025
• CPC Class Codes: H04L 2012/2849 Audio/video appliances
• CPC Class Codes: H04L 67/1095 Replication or mirroring of data, e.g. scheduling or transport for data synchronisation between network nodes

Abstract

The subject disclosure relates to synchronizing among network nodes in a multi-master synchronization environment that extend a knowledge based synchronization framework to include notions of object quality. In one embodiment, additional dimension(s) are placed on a knowledge vector for a given version of an object that represent quality information for the object, which is accounted for during the synchronization process to allow nodes to decide what types of qualities of objects should be conveyed to them as part of the synchronization process. Other embodiments include tombstoning objects to avoid future synchronization with respect to same objects maintained by other nodes in the multi-master synchronization environment. Advantageously, according to the synchronization framework, endpoints can synchronize data in a way that allows a definition and consideration of quality of one or more objects of the synchronized data for purposes of a knowledge exchange.

Claims

1. A method for synchronizing a set of objects between a first node and a second node of a plurality of nodes communicatively coupled via one or more networks in a multi-master synchronization environment, comprising:

for a given data scope, exchanging synchronization knowledge between the first node and the second node for a set of objects being represented on both nodes, wherein synchronization knowledge of the first node and the second node includes synchronization metadata representing corresponding versions for the objects of the set of objects represented on the first node and second node, respectively, and wherein representation of the synchronization knowledge is independent of data type;

ascertaining whether an object underwent a change to a desired qualitative feature based on the synchronization knowledge exchange, wherein the desired qualitative feature is an incremental quality identified from a plurality of potential qualitative features associated with the object, and wherein the object is receivable by the first node or the second node whichever is a receiving node; and

updating the synchronization metadata of the receiving node to include transform metadata that indicates a first knowledge by the receiving node of a first version of the object with a first transform applied and a second knowledge of a second version of the object with a second transform applied;

wherein the updating comprises comparing the synchronization knowledge of the first node and the second node to determine a collective knowledge of quality information for the set of objects; and

wherein the updating further comprises selecting the object as an object to synchronize based on the collective knowledge.

2. The method of claim 1, further including:

determining, based on at least one predefined criterion, whether the object to which the first transform is applied is desirable to the receiving node, wherein the determining includes comparing the first transform with the second transform.

3. The method of claim 2, further including:

if the object to which the first transform is applied is not desirable to the receiving node, deleting the object by the receiving node.

4. The method of claim 3, further including:

if the object to which the first transform is applied is not desirable to the receiving node, further comprising tombstoning the object by updating the synchronization metadata of the receiving node to reflect that the receiving node has learned of the version of the object with the first transform applied, but does not desire to receive the version as part of future knowledge exchanges with other nodes in the multi-master synchronization environment.

5. The method of claim 1, further including:

wherein the updating of the synchronization metadata further includes augmenting the synchronization metadata with transform metadata that indicates knowledge of a difference between the first transform and the second transform for a same object.

6. The method of claim 1, further including:

wherein the updating of the synchronization metadata further includes augmenting the synchronization metadata with transform metadata that indicates knowledge of objects of differing first and second transforms and that the receiving node has deleted the object to which the first transform is applicable or deleted the object to which the second transform is applicable.

7. The method of claim 6, wherein the updating of the synchronization metadata comprises preventing future knowledge exchanges in which the receiving node would receive the deleted object again from the same or other nodes, at least in part by maintaining synchronization metadata describing the action of deleting the object, and by defining a rule that rejects synchronization relative to a future object having a same qualitative feature as the deleted object.

8. The method of claim 6, further including:

wherein the augmenting of the synchronization metadata includes augmenting the synchronization metadata for the object with a Boolean value that indicates that the receiving node has deleted the object to which the first transform is applicable or deleted the object to which the second transform is applicable.

9. The method of claim 1, wherein the exchanging includes comparing, within the data scope, local synchronization knowledge of the first node concerning the set of objects represented on the first node with the external synchronization knowledge of the second node including taking into account any objects that have been learned by the first node or second node as part of the local synchronization knowledge or the external synchronization knowledge, but have been deleted on the first node or the second node, respectively.

10. The method of claim 9, further comprising:

determining changes to the external knowledge of the set of objects represented on the second node and corresponding changes to the set of objects represented on the second node based on the comparing; and

transmitting the changes to the external knowledge and the corresponding changes to the set of objects to the second node.

11. A node device of a plurality of nodes connectable via one or more networks that synchronizes a set of objects between the node and an other node of the plurality of nodes in a multi-master synchronization environment, comprising:

a synchronization component coupled to a processor and configured to synchronize the set of objects between the node and the other node of the plurality of nodes, including;

a synchronization communications component configured to initiate a synchronization with the other node via a synchronization protocol that defines, independent of data type, metadata structure for a knowledge exchange between the other node and the node, wherein the synchronization communications component is further configured to transmit to the other node a request to synchronize with the set of objects based on the synchronization protocol, and wherein the synchronization communications component is further configured to receive external knowledge of the set of objects from the other node in response to the request including other node object first versioning information corresponding to the set of objects represented on the other node and other node object second versioning information corresponding to the other node object first versioning information, wherein the other node object second versioning information versions the other node object first versioning information and represents different fidelity levels for versions of the set of objects represented by the other node object first versioning information; and

a synchronization analysis component configured to ascertain whether an object underwent a change to a desired qualitative feature in the other node based on the external knowledge of the set of objects, wherein the desired qualitative feature is an incremental quality identified from a plurality of potential qualitative features associated with the object, the synchronization analysis component further configured to update local knowledge of the set of objects represented on the node and corresponding node object versioning information based on whether the external knowledge of the set of objects includes the change to the desired qualitative feature associated with the object;

wherein the synchronization component is configured to compare synchronization data of the node and the other node to determine a collective knowledge of quality information for the set of objects; and

wherein the synchronization component is further configured to select the object as an object to synchronize based on the collective knowledge.

12. The node device of claim 11, wherein, for each object of the set of objects represented by an updated local knowledge having corresponding node object first versioning information and corresponding node object second versioning information, wherein the synchronization analysis component is configured to determine, by comparing second versioning information represented on the node and the other node for a given first version of the object represented by the first versioning information, whether a given second version of the given first version represented by the second versioning information is desirable to synchronize to either the node or the other node.

13. The node device of claim 11, wherein the synchronization protocol does not prescribe any schema of the actual data being synchronized between the node and the other node.

14. A method for synchronizing a set of objects between a first node and a second node of a plurality of nodes communicatively coupled via one or more networks in a multi-master synchronization environment, comprising:

changing a qualitative characteristic of at least one object of the set of objects by the first node;

updating synchronization knowledge metadata of the first node concerning the at least one object to include quality metadata indicating the change to the qualitative characteristic, wherein representation of the synchronization knowledge metadata is independent of data type;

ascertaining whether the at least one object underwent a change to a desired qualitative characteristic preferred by the second node, wherein the desired qualitative characteristic is an incremental quality identified from a plurality of potential qualitative features associated with the at least one object; and

synchronizing with the second node by the first node including transmitting, by the first node to the second node, an updated synchronization knowledge metadata of the first node, wherein the transmitting includes transmitting version metadata for objects of the set of objects corresponding to versions of the set of objects represented on the first node and any corresponding quality metadata associated with the versions of the set of objects;

wherein the synchronizing comprises comparing synchronization data of the first node and the second node to determine a collective knowledge of quality information for the set of objects; and

wherein the synchronizing further comprises selecting the at least one object as an object to synchronize based on the collective knowledge.

15. The method of claim 14, further including:

wherein the updating includes updating in response to the changing of the qualitative characteristic of the at least one object.

16. The method of claim 14, further including:

determining whether the changing changed the qualitative characteristic of the at least one object based on at least one criterion defined by the first node.

17. The method of claim 16, wherein the determining includes determining whether the changing transformed data represented by the at least one object without causing a destruction of the data.

18. The method of claim 16, wherein the determining includes determining whether the changing transformed data represented by the at least one object without causing a change in a fidelity of the data.

19. The method of claim 18, wherein the determining includes determining whether the changing transformed the data represented by the at least one object while degrading the fidelity of the data.

20. The method of claim 18, wherein the determining includes determining whether the changing transformed the data represented by the at least one object while enhancing the fidelity of the data.

21. The method of claim 16, wherein the updating of the synchronization knowledge metadata of the first node to indicate the change to the qualitative characteristic includes leaving the current version metadata for the at least one object unchanged and storing, with the current version metadata, additional quality version metadata that differentiates different qualities for the same versions of the at least one object.