System and methods for exchanging messages between a client and a server for synchronizing datasets

• US 6,535,892 B1
• Filed: 05/13/2002
• Issued: 03/18/2003
• Est. Priority Date: 03/08/1999
• Status: Active Grant

• Current Assignee: Intellisync Corporation (Nokia Corporation)
• Original Assignee: Starfish Software, Inc. (Nokia Corporation)
• Inventors: Dube, Bryan, LaRue, Chris
• Primary Examiner(s): Corrielus, Jean M.
• Application Number:
  US10/145,251
• Time in Patent Office: 309 Days
• Field of Search: 707/10, 707/200, 707/201, 707/203, 709/201, 709/217, 709/226
• US Class Current: 1/1
• 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: Y10S 707/99952 Coherency, e.g. same view to multiple users
• CPC Class Codes: Y10S 707/99954 Version management

Abstract

A system and methods for synchronizing information in datasets via a communication medium are provided that are suitable for synchronizing even across communication mediums that are susceptible to high latency, non-FIFO (non-First-In-First-Out) delivery order, or other adverse characteristics. According to an aspect of the invention, in an information processing system, a method for synchronizing a first dataset with at least a second dataset via a communication medium includes a step of storing information that is indicative of a first version of user data of the first dataset, wherein the first version has been involved in prior use for synchronizing with the second dataset. The method further includes steps of identifying a change in the second dataset that is new relative to the first version of the user data of the first dataset; via the communication medium, communicating the change in the second dataset and indicating the first version based on the stored information; determining whether user data currently in the first dataset has changed relative to the first version that was indicated in the communicating and indicating step; deciding whether to commit the communicated change to the first dataset based at least in part on the determining step; and committing the communicated change to the first dataset if the communicated change is decided to be committed in the deciding step.

Claims

1. A method of communicating between a client device and a server device to enable synchronization between a client dataset in the client device and a server dataset in the server device, the client device and the server device communicating with one another over a communication medium, the method comprising:

a first ply, in which the client device sends to the server device, over the communication medium, changes that have been made to the client dataset;

a second ply, in which the server device sends to the client device, over the communication medium, changes that have been made to the server dataset, said changes including an addition of a new record;

the client device sending to the server device, over the communication medium, a new record mapping indicating a client record ID for a new record added to the client dataset in response to the addition received from the server device; and

the server device sending to the client device, over the communication medium, an acknowledgement of receipt of the new record mapping,

wherein the steps of the client device sending the new record mapping to the server device and the server device sending an acknowledgement of the new record mapping may occur during third and fourth plies, respectively, of the same synchronization, or these steps may occur during the first and second plies, respectively, of a subsequent synchronization.

2. The method of claim 1, wherein during the second ply, the server device also sends to the client device an acknowledgement for each of the changes received from the client device in the first ply.

3. The method of claim 1, wherein the client device may request during the first ply that the server device send acknowledgements for each of the changes from the client device and, if the client device makes such a request, the server device sends to the client device, during the second ply, an acknowledgement for each of the changes received from the client device in the first ply.

4. The method of claim 2, wherein during the same ply that the client device sends the new record mapping to the server device, the client device also sends to the server device an acknowledgement for each of the changes received from the server device in the second ply.

5. The method of claim 3, wherein the server device may request during the second ply that the client device send acknowledgements for each of the changes from the server device and, if the server device makes such a request, the client device sends to the server device, during the same ply that the client device sends the new record mapping, an acknowledgement for each of the changes received from the server device in the second ply.

6. The method of claim 1, wherein each ply of the method consists of a single message.

7. The method of claim 1, wherein each ply of the method consists of multiple messages.

8. The method of claim 1, wherein each ply of the method may comprise either a single message or multiple messages.

9. The method of claim 1, wherein the client device allows a user to make changes to the client dataset during a first synchronization process, but any changes that are made after the first ply is completed are sent to the server during a subsequent synchronization process.

10. The method of claim 9, wherein the server device allows a user to make changes to the server dataset during a first synchronization process, but any changes that are made after the second ply is completed are sent to the client during a subsequent synchronization process.

11. The method of claim 1, wherein when the server device sends changes to the client device, the server device sends a client record ID along with each modification and each deletion and a server record ID along with each addition.

12. The method of claim 11, wherein the new record mapping further includes the server record ID sent along with the addition.

13. A method for a client device to communicate with a server device to enable synchronization between a client dataset in the client device and a server dataset in the server device, the client device and the server device communicating with one another over a communication medium, the method comprising:

a first ply, in which the client device sends to the server device, over the communication medium, changes that have been made to the client dataset;

a second ply, in which the client device receives from the server device, over the communication medium, changes that have been made to the server dataset, said changes including an addition of a new record;

the client device sending to the server device, over the communication medium, a new record mapping indicating a client record ID for a new record added to the client dataset in response to the addition received from the server device; and

the client device receiving from the server device, over the communication medium, an acknowledgement of receipt of the new record mapping,

wherein the steps of the client device sending the new record mapping to the server device and the client device receiving an acknowledgement of the new record mapping may occur during third and fourth plies, respectively, of the same synchronization, or these steps may occur during the first and second plies, respectively, of a subsequent synchronization.

14. A method for a server device to communicate with a client device to enable synchronization between a client dataset in the client device and a server dataset in the server device, the client device and the server device communicating with one another over a communication medium, the method comprising:

a first ply, in which the server device receives from the client device, over the communication medium, changes that have been made to the client dataset;

a second ply, in which the server device sends to the client device, over the communication medium, changes that have been made to the server dataset, said changes including an addition of a new record;

the server device receiving from the client device, over the communication medium, a new record mapping indicating a client record ID for a new record added to the client dataset in response to the addition received from the server device; and

the server device sending to the client device, over the communication medium, an acknowledgement of receipt of the new record mapping,

wherein the steps of the server device receiving the new record mapping from the client device and the server device sending an acknowledgement of the new record mapping may occur during third and fourth plies, respectively, of the same synchronization, or these steps may occur during the first and second plies, respectively, of a subsequent synchronization.

15. A method of synchronizing a client dataset in a client device with a server dataset in a server device using multiple synchronization sessions, the client device and the server device communicating with one another over a communication medium, the method comprising:

the client device initiating a first synchronization session with the server device, the first synchronization session comprising;

a first ply, in which the client device sends to the server device, over the communication medium, changes that have been made to the client dataset;

a second ply, in which the server device sends to the client device, over the communication medium, changes that have been made to the server dataset, said changes including an addition of a new record, wherein the server device performs a conflict resolution between the first ply and the second ply, so that the changes sent to the client device are conflict-free;

a third ply, in which the client device sends to the server device, over the communication medium, a new record mapping indicating a client record ID for a new record added to the client dataset in response to the addition received from the server device; and

a fourth ply, in which the server device sends to the client device, over the communication medium, an acknowledgement of receipt of the new record mapping,

wherein the client device permits a user to make changes to the client dataset during the first synchronization session, but any changes made to the client dataset after the first ply are held by the client device for synchronization during a subsequent synchronization session.

16. A method for a client device to communicate with a server device during multiple synchronization sessions to facilitate synchronizing a client dataset in the client device with a server dataset in the server device, the client device and the server device communicating with one another over a communication medium, the method comprising:

the client device initiating a first synchronization session with the server device, the first synchronization session comprising;

a first ply, in which the client device sends to the server device, over the communication medium, changes that have been made to the client dataset;

a second ply, in which the client device receives from the server device, over the communication medium, changes that have been made to the server dataset, said changes including an addition of a new record, wherein the client device treats the received changes as conflict-free changes;

a third ply, in which the client device sends to the server device, over the communication medium, a new record mapping indicating a client record ID for a new record added to the client dataset in response to the addition received from the server device; and

a fourth ply, in which the client device receives from the server device, over the communication medium, an acknowledgement of receipt of the new record mapping,

wherein the client device permits a user to make changes to the client dataset during the first synchronization session, but any changes made to the client dataset after the first ply are held by the client device for synchronization during a subsequent synchronization session.

17. The method of claim 16, wherein during the second ply, the client device also receives from the server device an acknowledgement for each of the changes sent by the client device in the first ply.

18. The method of claim 17, wherein during the third ply, the client device also sends to the server device an acknowledgement for each of the changes received from the server device in the second ply.

19. The method of claim 16, wherein the client device may request during the first ply that the server device send acknowledgements for each of the changes from the client device and, if the client device makes such a request, the client device receives from the server device, during the second ply, an acknowledgement for each of the changes sent by the client device in the first ply.

20. The method of claim 19, wherein if the server device requests during the second ply that the client device send acknowledgements for each of the changes from the server device, the client device sends to the server device, during the third ply, an acknowledgement for each of the changes received from the server device in the second ply.

21. The method of claim 16, wherein each ply of the method consists of a single message.

22. The method of claim 16, wherein each ply of the method consists of multiple messages.

23. The method of claim 16, wherein each ply of the method may comprise either a single message or multiple messages.

24. The method of claim 16, wherein changes received from the server device during the second ply contain a client record ID for each modification and each deletion and a server record ID for each addition.

25. The method of claim 24, wherein the new record mapping further includes the server record ID contained in the addition.

26. A client device in a synchronization system, the client device communicating with a server device over a communication medium to enable synchronization between a client dataset in the client device and a server dataset in the server device, the client device comprising:

means for sending to the server device, changes that have been made to the client dataset, the changes being sent over the communication medium in a first ply;

means for receiving from the server device, changes that have been made to the server dataset, the changes being sent over the communication medium in a second ply, the changes including an addition of a new record;

means for sending to the server device, over the communication medium, a new record mapping indicating a client record ID for a new record added to the client dataset in response to the addition received from the server device; and

means for receiving from the server device, over the communication medium, an acknowledgement of receipt of the new record mapping,

wherein the steps of sending the new record mapping to the server device and receiving the acknowledgement of the new record mapping may occur during third and fourth plies, respectively, of the same synchronization, or these steps may occur during the first and second plies, respectively, of a subsequent synchronization.

27. A server device in a synchronization system, the server device communicating with a client device over a communication medium to enable synchronization between a client dataset in the client device and a server dataset in the server device, the server device comprising:

means for receiving from the client device, changes that have been made to the client dataset, the changes being sent over the communication medium in a first ply;

means for sending to the client device, changes that have been made to the server dataset, the changes being sent over the communication medium in a second ply, the changes including an addition of a new record;

means for receiving from the client device, over the communication medium, a new record mapping indicating a client record ID for a new record added to the client dataset in response to the addition received from the server device; and

means for sending to the client device, over the communication medium, an acknowledgement of receipt of the new record mapping,

wherein the steps of receiving the new record mapping from the client device and sending the acknowledgement of the new record mapping may occur during third and fourth plies, respectively, of the same synchronization, or these steps may occur during the first and second plies, respectively, of a subsequent synchronization.

28. A client device in a synchronization system, the client device communicating with a server device during multiple synchronization sessions to facilitate synchronizing a client dataset in the client device with a server dataset in the server device, the client device and the server device communicating with one another over a communication medium, the client device comprising:

means for performing a first synchronization session with the server device, said means comprising;

means for sending to the server device, changes that have been made to the client dataset, said changes being sent over the communication medium during a first ply;

means for receiving from the server device, changes that have been made to the server dataset, said changes including an addition of a new record, said changes being received over the communication medium during a second ply, wherein the client device treats the received changes as conflict-free changes;

means for sending to the server device, a new record mapping indicating a client record ID for a new record added to the client dataset in response to the addition received from the server device, said new record mapping being sent over the communication medium during a third ply; and

means for receiving from the server device, an acknowledgement of receipt of the new record mapping, said acknowledgement being received over the communication medium during a fourth ply;

means for permitting a user to make changes to the client dataset during the first synchronization session; and

means for holding any changes made to the client dataset after the first ply for synchronization during a subsequent synchronization session.