Asynchronous Replication

• US 20090172041A1
• Filed: 12/27/2007
• Published: 07/02/2009
• Est. Priority Date: 12/27/2007
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Singha Bose, Miko Arnab Sakhya, Clarke, Simon P.
• Granted Patent: US 8,239,345 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 16/172 Caching, prefetching or hoarding of files
• CPC Class Codes: H04L 67/1095 Replication or mirroring of data, e.g. scheduling or transport for data synchronisation between network nodes

Abstract

Contents of a copy of a server file may be saved to a down load file, a base file, and a working file. An indication may be received from an application that the application has edited the working file and a copy of the edited working file may be saved to an upload file. A server computer may be queried to determine if the server file on the server computer has been changed. If the server file on the server computer has not been changed, the server file on the server computer may be updated with contents of the upload file. If the server file on the server computer has been changed, a three-way merge of the upload file, the base file, and the changed server file on the server computer may be performed. Then the server file on the server computer may be updated with the three-way merge results.

Claims

1. A method for providing asynchronous replication, the method comprising:

saving contents of a copy of a server file to a down load file, a base file, and a working file;

receiving an indication from an application that the application has edited the working file;

saving, in response to the indication, a copy of the edited working file to an upload file;

querying a server computer to determine if the server file on the server computer has been changed;

when it is determined that the server file on the server computer has not been changed, updating the server file on the server computer with contents of the upload file; and

when it is determined that the server file on the server computer has been changed,

performing a three-way merge of the upload file, the base file, and the changed server file on the server computer, and

updating the server file on the server computer with results of the three-way merge.

2. The method of claim 1, further comprising receiving, from the application, a request for the copy of the server file.

3. The method of claim 1, further comprising requesting the copy of the server file from the server computer.

4. The method of claim 1, further comprising receiving the copy of the server file from the server computer.

5. The method of claim 1, further comprising replacing, when it is determined that the server file on the server computer has been changed, contents of the down load file and contents of the base file with the results of the three-way merge.

6. The method of claim 1, wherein receiving the indication from the application comprises receiving the indication from the application wherein the application, the down load file, the base file, the working file, and the upload file are on a client computer.

7. The method of claim 1, wherein saving the copy of the edited working file to the upload file comprises saving the copy of the edited working file to the upload file in response to a user initiated command to the application to save the working file.

8. The method of claim 1, wherein saving the copy of the edited working file to the upload file comprises saving the copy of the edited working file to the upload file in response to a user initiated command to the application to close the application.

9. The method of claim 1, wherein performing the three-way merge comprises the application performing the three-way merge.

10. The method of claim 1, wherein querying the server computer to determine if the server file on the server computer has been changed comprises querying the server computer in response to the application losing a lock on the server file on the server computer.

11. The method of claim 1, wherein querying the server computer to determine if the server file on the server computer has been changed comprises querying the server computer in response to a client computer on which the application is running losing and regaining a connection with the server computer.

12. The method of claim 1, wherein querying the server computer to determine if the server file on the server computer has been changed comprises querying the server computer in response to a client computer, on which the application is running, being connected to the server computer.

13. The method of claim 1, wherein querying the server computer to determine if the server file on the server computer has been changed comprises querying the server computer in response to a client computer, on which the application is running, being connected to the server computer in response to a user command.

14. The method of claim 1, wherein querying the server computer to determine if the server file on the server computer has been changed comprises querying the server computer in response to a predetermined schedule.

15. The method of claim 1, wherein querying the server computer to determine if the server file on the server computer has been changed comprises querying the server computer in response to an available bandwidth of a connection between a client computer on which the application is running and the server computer is greater than a predetermined value.

16. The method of claim 1, further comprising:

receiving updates to the server file from the server; and

saving the received updates to the download file and to the working file.

17. The method of claim 1, wherein updating the server file on the server computer with contents of the upload file comprises:

performing a diff between the base file and the upload file to determine a difference between the base file and the upload file; and

transmitting the difference between the base file and the upload file to the server computer from a client computer on which the application is running and on which the base file and the upload file reside.

18. The method of claim 1, wherein updating the server file on the server computer with results of the three-way merge comprises:

performing a diff between the results of the three-way merge and the server file to determine the difference between the results of the three-way merge and the server file; and

transmitting the results of the three-way merge and the server file to the server computer from a client computer on which the application is running and on which the three-way merge was performed.

19. A computer-readable medium which stores a set of instructions which when executed performs a method for providing asynchronous replication, the method executed by the set of instructions comprising:

receiving, from an application, a request for a copy of a server file;

requesting the copy of the server file from a server computer;

receiving the copy of the server file from the server computer;

saving contents of the copy of the server file to a down load file, a base file, and a working file;

receiving an indication from the application that the application has edited the working file;

saving, in response to the indication, a copy of the edited working file to an upload file;

querying the server computer to determine if the server file on the server computer has been changed;

when it is determined that the server file on the server computer has not been changed, updating the server file on the server computer with contents of the upload file; and

when it is determined that the server file on the server computer has been changed,

performing a three-way merge of the upload file, the base file, and the changed server file on the server computer,

updating the server file on the server computer with results of the three-way merge, and

replacing the contents of the down load file and the base file with the results of the three-way merge.

20. A system for providing asynchronous replication, the system comprising:

a memory storage; and

a processing unit coupled to the memory storage, wherein the processing unit is operative to;

save a copy of an edited working file to an upload file;

when it is determined that a server file on a server computer has not been changed, update the server file on the server computer with contents of the upload file; and

when it is determined that the server file on the server computer has been changed,

perform a three-way merge of the upload file, a base file, and the changed server file on the server computer, and

update the server file on the server computer with results of the three-way merge.