INFORMATION SYNCHRONISATION

• US 20100070470A1
• Filed: 10/10/2008
• Published: 03/18/2010
• Est. Priority Date: 09/17/2008
• Status: Active Grant

• Current Assignee: Sage Technologies Limited (Sage Group PLC)
• Original Assignee: Sage Technologies Limited (Sage Group PLC)
• Inventors: Milencovici, Tudor, Jouhier, Bruno
• Granted Patent: US 9,116,972 B2
• Time in Patent Office: Days
• US Class Current: 707/610
• CPC Class Codes: G06F 16/273 Asynchronous replication or reconciliation

Abstract

A method of synchronising at least first and second instances of an information set comprising a plurality of entries, wherein said first and second instances are located on different nodes of a system, the method comprising:

• • attaching a node value and current logical clock value pair to each entry in the information set of a given instance when said entry in the given instance is changed;
  • generating a digest for each of the at least first and second instances of the information set, wherein said digests comprise logical clock information of a last synchronisation event of one of the at least first and second instances with another of the at least first and second instances of the information set; and
  • synchronising the at least first and second instances of the information set by comparing the digests and reconciling the at least first and second instances.

Claims

1. A method of synchronising at least first and second instances of an information set comprising a plurality of entries, wherein said first and second instances are located on different nodes of a system, the method comprising:

attaching a node value and current logical clock value pair to each entry in the information set of a given instance when said entry in the given instance is changed;

generating a digest for each of the at least first and second instances of the information set, wherein said digests comprise logical clock information of a last synchronisation event of one of the at least first and second instances with another of the at least first and second instances of the information set; and

synchronising the at least first and second instances of the information set by comparing the digests and reconciling the at least first and second instances.

2. The method of claim 1, wherein an existing node value and current logical clock value pair of an entry is deleted and replaced with a new node value and current logical clock value pair when said entry is changed.

3. The method of claim 2, wherein a timestamp value is attached to each data entry when said entry is changed, in addition to the node value and current logical clock value pair.

4. The method claim 1, wherein the synchronisation is performed in a bi-directional manner.

5. The method of claim 1, wherein the synchronisation is performed for one information set at a time.

6. The method of claim 1, wherein each digest is located at a node to which it relates.

7. The method of claim 1, wherein the digest comprises a node value and logical clock value pair for each node of the system.

8. The method of claim 7, wherein the digest additionally includes a conflict priority value for each node of the system.

9. The method of claim 1, wherein the node value and current logical clock value pair and/or the digest are carried by a syndication feed.

10. The method of claim 1, wherein the node values are URLs.

11. The method of claim 1, wherein two digests are provided for each synchronisation event.

12. The method of claim 11, wherein the two digests relate to a state of one of the nodes before a modification event and after a modification event respectively.

13. A synchronisation device operable to perform the method of claim 1.

14. The synchronisation device of claim 13, which is an application running on a computer system.

15. A computing system comprising a plurality of nodes, wherein each node incorporates an instance of an information set, the computing system being operable to synchronise the instances of the information set, and comprising at least one synchronisation logic element operable to:

attach a node value and current logical clock value pair to each entry in the information set of a given instance when said entry in the given instance is changed;

generate a digest for each of the instances of the information set, wherein said digests comprise logical clock information of a last synchronisation event of one of the instances with another of the at least instances of the information set; and

synchronise the instances of the information set by comparing the digests and reconciling the at least first and second instances.

16. The computing system of claim 15, wherein the synchronisation logic element comprises a synchronisation endpoint for each node or for each instance of the information set.

17. The computing system of claim 15, wherein the synchronisation logic element comprises one or more synchronisation engines operable to drive exchanges of messages between synchronisation endpoints.

18. The computing system of claim 17, wherein the synchronisation engines and synchronisation endpoints reside on different computers.

19. The computing system of claim 17 wherein a synchronisation engine may reside on the same computer as a synchronisation endpoint.

20. The computing system of claim 16, wherein each synchronisation endpoint is operable to perform the attaching and digest generation for its given node.

21. The computing system of claim 16, wherein the plurality of synchronisation engines are operable to communicate with the endpoints to perform the synchronisation function.

22. The computing system of claim 16, wherein the nodes are computer applications running on one computer or

23. The computing system of claim 16, wherein the nodes are computer applications running on different computers.

24. A computer program product comprising instructions, which when run on a computer are operable to implement a method of synchronising at least first and second instances of an information set comprising a plurality of entries, wherein said first and second instances are located on different nodes of a computer system, the method comprising:

attaching a node value and current logical clock value pair to each entry in the information set of a given instance when said entry in the given instance is changed;

generating a digest for each of the at least first and second instances of the information set, wherein said digests comprise logical clock information of a last synchronisation event of one of the at least first and second instances with another of the at least first and second instances of the information set; and

synchronising the at least first and second instances of the information set by comparing the digests and reconciling the at least first and second instances.