System and methods for synchronizing datasets using cooperation among multiple synchronization engines

• US 6,401,104 B1
• Filed: 07/03/1999
• Issued: 06/04/2002
• Est. Priority Date: 07/03/1999
• Status: Expired due to Term

• Current Assignee: Intellisync Corporation (Nokia Corporation)
• Original Assignee: Starfish Software, Inc. (Nokia Corporation)
• Inventors: Dube, Bryan, LaRue, Chris
• Primary Examiner(s): Alam, Hosain T.
• Assistant Examiner(s): Truong, Cam Y T
• Application Number:
  US09/347,447
• Time in Patent Office: 1,067 Days
• Field of Search: 707/200-204
• US Class Current: 1/1
• CPC Class Codes: G06F 16/273 Asynchronous replication or reconciliation
• CPC Class Codes: Y10S 707/99952 Coherency, e.g. same view to multiple users
• CPC Class Codes: Y10S 707/99953 Recoverability
• CPC Class Codes: Y10S 707/99954 Version management

Abstract

A system and methods for synchronizing datasets are provided that are especially suitable and efficient for a user who has three or more datasets that need to be occasionally synchronized, with no one dataset or synchronization system being guaranteed to participate in every synchronization. Synchronization status information, such as correspondences between data records of particular multiple datasets, is stored with more than one of the datasets. When two datasets that contain synchronization status information synchronize with each other, they not only synchronize user data and exchange status information involving each other, but they also synchronize and exchange status information involving “third-party” datasets that may not be participating in the synchronization. In this way, synchronization status information collected in an earlier synchronization is made available in a later synchronization, even if the earlier and later synchronizations are not conducted by a same synchronization system or do not both include a common, permanently designated “hub” dataset. Further, when datasets being synchronized are found to contain mutually-duplicative data records, the data records are intelligently mapped to each other as being corresponding so as to avoid or minimize causing of changes to be made, in the data records, that would make synchronization status information stored in another dataset to become obsolete.

Claims

1. A method for synchronizing multiple datasets in a synchronization system, the system comprising a first synchronizer, a second synchronizer, a first dataset, a second dataset and a third dataset, wherein a new entry has been made to a first record in the first dataset, the method comprising:

synchronizing the first dataset with the second dataset using the first synchronizer, including propagating the new entry to a corresponding second record in the second dataset and storing information mapping the first record in the first dataset to the corresponding second record in the second dataset;

synchronizing the first dataset with the third dataset using the second synchronizer, including propagating the new entry to a corresponding third record in the third dataset and storing information mapping the first record in the first dataset to the corresponding third record in the third dataset;

communicating mapping information regarding the first record between the first synchronizer and the second synchronizer; and

using the mapping information between the first and second records and between the first and third records to determine that the second and third records should be mapped together.

2. The method of claim 1, wherein each of the first synchronizer, the second synchronizer, the first dataset, the second dataset and the third dataset is on a separate data product.

3. The method of claim 1, wherein the first synchronizer communicates to the second synchronizer, information mapping the first record in the first dataset to the corresponding second record in the second dataset, and the second synchronizer uses this mapping information to determine that the second and third records should be mapped together.

4. The method of claim 1, wherein the step of communicating the mapping information occurs during a synchronization between the second and third datasets.

5. The method of claim 4, wherein the second dataset is a reference dataset for the first synchronizer and the third dataset is a reference dataset for the second synchronizer.

6. The method of claim 4, wherein the synchronization between the second and third datasets is performed by the first synchronizer.

7. A method for synchronizing multiple datasets in a synchronization system, the synchronization system comprising a first and a second synchronizer and a plurality of datasets, wherein a user has made a first change in a first dataset, the method comprising:

synchronizing a first and a second dataset using the first synchronizer, so that the first synchronizer becomes aware of the first change and propagates the first change to the second dataset;

synchronizing the second and a third dataset so that the first change is propagated from the second dataset to the third dataset;

communicating from the first synchronizer to the second synchronizer that the first change has been made to the first dataset; and

synchronizing the first and third datasets using the second synchronizer, wherein the second synchronizer does not send the first change from the third dataset to the first dataset because the second synchronizer is aware that the first change has already been made to the first dataset.

8. The method of claim 7, wherein the step of communicating from the first synchronizer to the second synchronizer occurs during the synchronization between the second and third datasets.

9. The method of claim 8, wherein the second dataset is a reference dataset for the first synchronizer and the third dataset is a reference dataset for the second synchronizer.

10. A synchronization system for synchronizing multiple datasets, the system comprising:

a plurality of datasets to be synchronized with one another, the plurality of datasets residing on one or more data products;

a first synchronizer for synchronizing one or more of said datasets; and

a second synchronizer for synchronizing one or more of said datasets,

wherein said first synchronizer receives a first change from a first one of said plurality of datasets during a first synchronization, said first synchronizer subsequently communicates said first change to said second synchronizer, and said second synchronizer subsequently sends said first change to a second of said plurality of datasets during a second synchronization.

11. The system of claim 10, wherein the first synchronizer is implemented on a personal computer and the second synchronizer is implemented on a first server computer.

12. The system of claim 11, wherein the second dataset is also implemented on a server computer.

13. The system of claim 12, wherein the first dataset is implemented on a handheld device that may be intermittently connected to said personal computer.

14. The system of claim 13, wherein the second dataset is implemented on the first server computer.

15. The system of claim 14, wherein the handheld device may also be intermittently connected to the first server computer by a wireless communication link.

16. A method for synchronizing multiple datasets in a synchronization system, the system comprising a first synchronizer having a first reference dataset, a second synchronizer having a second reference dataset, and a third dataset, the method comprising:

synchronizing said first reference dataset with said second reference dataset, and communicating from said first synchronizer to said second synchronizer status information about said third dataset; and

synchronizing said third dataset using said second synchronizer, said second synchronizer using said status information about said third dataset during the synchronization.

17. The method claim 16, wherein said status information comprises mapping information related to records in said third dataset.

18. The method claim 16, wherein said status information comprises a timestamp related to a record in said third dataset.

19. The method of claim 18, wherein said timestamp is made by a real-time clock.

20. The method of claim 18, wherein said timestamp comprises a change counter value.

21. A method for synchronizing multiple datasets in a synchronization system, the system comprising a first and a second synchronizer and a first dataset, the method comprising:

synchronizing the first dataset using the first synchronizer, including synchronizing a first change with the first dataset;

communicating from the first synchronizer to the second synchronizer that the first change was synchronized with the first dataset; and

synchronizing the first dataset using the second synchronizer, wherein the second synchronizer does not synchronize the first change with the first dataset because the second synchronizer is aware that the first change has already been synchronized with the first dataset.

22. The method of claim 21, wherein the step of communicating from the first synchronizer to the second synchronizer is performed during a synchronization involving a first reference dataset associated with the first synchronizer and a second reference dataset associated with the second synchronizer.

23. The method of claim 22, wherein the synchronization involving said first reference dataset and said second reference dataset additionally involves a third dataset.

24. A synchronization system for synchronizing multiple datasets, the system comprising:

a plurality of datasets to be synchronized with one another, the plurality of datasets residing on one or more data products;

a first synchronizer for synchronizing one or more of said datasets; and

a second synchronizer for synchronizing one or more of said datasets,

wherein the first synchronizer performs a first synchronization with one or more of said plurality of datasets, said first synchronizer subsequently communicates information relative to said first synchronization to said second synchronizer, and said second synchronizer subsequently uses said information relative to said first synchronization during another synchronization with one or more of said plurality of datasets.

25. The method of claim 24, wherein said communication from said first synchronizer to said second synchronizer occurs during a second synchronization involving both said first and second synchronizers.

26. The method of claim 25, wherein the first synchronization involves a first dataset and a second dataset, the second synchronization involves the second dataset and a third dataset and the another synchronization involves the first dataset and the third dataset.

27. A method for synchronizing multiple datasets in a synchronization system, the system comprising a first synchronizer, a second synchronizer and a first dataset, the first dataset having a first record, the first synchronizer maintaining a first status field for indicating the last synchronization time of the first record by the first synchronizer, the second synchronizer maintaining a second status field for indicating the last synchronization time of the first record by the second synchronizer, wherein a first change has been made to the first record in the first dataset, the method comprising:

the first synchronizer synchronizing the first dataset, so that the first dataset sends the first change to the first synchronizer and the first synchronizer updates the first status field based on the time of the synchronization;

the first synchronizer communicating to the second synchronizer the first change and the contents of the first status field; and

the second synchronizer storing the contents of the first status field, as received from the first synchronizer, into the second status field, and using the new contents of the second status field as the last synchronization time of the first record by the second synchronizer for a subsequent synchronization.

28. The method of claim 27, wherein the contents of the first and second status fields comprise a timestamp.

29. The method of claim 28, wherein the timestamp is made by a real-time clock.

30. The method of claim 28, wherein the timestamp comprises a change counter value.

31. A method for synchronizing multiple datasets in a synchronization system, the system comprising a first synchronizer, a second synchronizer and a first dataset, the first dataset having a first record, the first synchronizer maintaining a first status field for indicating a priority time of the first record, the second synchronizer maintaining a second status field for indicating the priority time of the first record, wherein a first change is made to the first record in the first dataset at a first priority time, the method comprising:

the first synchronizer synchronizing the first dataset, so that the first dataset sends the first change and the first priority time to the first synchronizer and the first synchronizer stores the first priority time in the first status field;

the first synchronizer communicating to the second synchronizer the first change and the contents of the first status field; and

the second synchronizer storing the contents of the first status field, as received from the first synchronizer, into the second status field, and using the new contents of the second status field as the priority time of the first record for a subsequent synchronization.