Method and apparatus for generating data change requests containing data consistency information in a peer-to-peer collaborative computer system

• US 7,490,126 B2
• Filed: 07/30/2003
• Issued: 02/10/2009
• Est. Priority Date: 07/19/1999
• Status: Expired due to Fees

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Ozzie, Jack E., Ozzie, Raymond E.
• Primary Examiner(s): Nguyen; Phuoc H
• Application Number:
  US10/630,150
• Publication Number:
  US 20050102364A1
• Time in Patent Office: 2,022 Days
• Field of Search: 709/205, 709/217, 709/225, 709/232
• US Class Current: 709/205
• CPC Class Codes: G06F 16/1767 Concurrency control, e.g. optimistic or pessimistic approaches
• CPC Class Codes: G06Q 10/10 Office automation; Time management
• CPC Class Codes: H04L 51/043 using or handling presence information
• CPC Class Codes: H04L 67/1095 Replication or mirroring of data, e.g. scheduling or transport for data synchronisation between network nodes
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]
• CPC Class Codes: H04L 9/40 Network security protocols
• CPC Class Codes: Y10S 707/99952 Coherency, e.g. same view to multiple users

Abstract

A distributed, activity-based collaboration system employs a data change request priority scheme for determining an order of execution of data change requests in effecting changes to local copies of data so as to optimize data consistency for collaborative activities. The data change request priority scheme can entail encoding sequence number information and dependency information in the data change requests, responsive to which data changes can be made, unmade and remade to the data.

Claims

1. Apparatus for formatting data change requests in a peer-to-peer, activity-based collaboration system having at least two collaborating computers, each with a local copy of data thereon and wherein the collaborating computers exchange data change requests during a collaboration session for effecting changes to the local copies of data for collaborative activities, the apparatus comprising:

a memory;

a processor;

data change request priority logic for inserting into each data change request priority information that determines an order of execution of data change requests; and

dependency collision resolution logic for inserting into selected data change requests dependency information for resolving a dependency collision between first and second data change requests which both depend for execution on a third data change request

wherein each of the collaborating computers and a user of that collaborating computer are an endpoint and wherein the dependency information comprises, for a data change request;

an identification of data to which the data change request pertains;

endpoint information identifying an endpoint from which the data change request was generated;

a data change request sequence number for the data change request; and

information identifying an endpoint and a data change request sequence number for a prior data change request on which the data change request depends.

2. The apparatus of claim 1 wherein the data change request sequence number is generated by the endpoint that generated that data change request.

3. The apparatus of claim 1, wherein the dependency information in a data change request further comprises characteristics of the endpoint that originated that data change request for use in resolving dependency collisions between that data change request and another data change request on the basis of, at least in part, the endpoint characteristics.

4. The apparatus of claim 1, wherein the dependency information further comprises a type of data change for use in resolving dependency collisions between data change requests on the basis of, at least in part, the types of the data change requests.

5. The apparatus of claim 1, wherein the dependency information further comprises a type of activity for use in resolving dependency collisions between a first data change request and a second data change request on the basis of, at least in part, the activity type.

6. The apparatus of claim 1, wherein the identification information comprises an identification code.

7. The apparatus of claim 6, wherein the sequence number information and dependency information are arranged in the data change request substantially in the form:

sequence number 1 @ endpoint 1;

sequence number 2 @ endpoint 2, wherein the sequence number 1 is the sequence of the data change request, the endpoint 1 is the endpoint from which the data change request was generated, the sequence number 2 is the sequence number of the prior data change request and the endpoint 2 is the endpoint from which the prior data change request was generated.

8. The apparatus of claim 1 wherein each data change request comprises a header portion and a payload portion and wherein the data change request priority logic comprises means for inserting the priority information into a header portion of a data change request.

9. The apparatus of claim 1 wherein each data change request comprises a header portion and a payload portion and wherein the dependency collision resolution logic comprises means for inserting the dependency information into a header portion of a data change request.

10. The apparatus of claim 1 wherein the dependency collision resolution logic comprises means for resolving a dependency collision between first and second data change requests based on an order in which endpoints that generated the first and second data change requests joined the collaboration session.

11. A method for formatting data change requests in a peer-to-peer, activity-based collaboration system having at least two collaborating computers, each with a local copy of data thereon and wherein the collaborating computers exchange data change requests during a collaboration session for effecting changes to the local copies of data for collaborative activities, the method comprising:

(a) inserting into each data change request priority information that determines an order of execution of data change requests; and

(b) inserting into selected data change requests dependency information for resolving a dependency collision between first and second data change requests which both depend for execution on a third data change request,

wherein the dependency information comprises, for a data change request;

an identification of data to which the data change request pertains;

endpoint information identifying an endpoint from which the data change request was generated;

a data change request sequence number for the data change request; and

information identifying an endpoint and a data change request sequence number for a prior data change request on which the data change request depends.

12. The method of claim 11 wherein each of the collaborating computers and a user of that collaborating computer are an endpoint and wherein the data change request sequence number comprises a sequence number generated by an endpoint that generated that data change request.

13. The method of claim 11, wherein each of the collaborating computers and a user of that collaborating computer are an endpoint and wherein the dependency information in a data change request comprises characteristics of an endpoint that originated that data change request for use in resolving dependency collisions between that data change request and another data change request on the basis of, at least in part, the endpoint characteristics.

14. The method of claim 11, wherein the dependency information comprises a type of data change for use in resolving dependency collisions between a first data change request and a second data change request on the basis of, at least in part, the data change type.

15. The method of claim 11, wherein the dependency information comprises a type of activity for use in resolving dependency collisions between a first data change request and a second data change request on the basis of, at least in part, the activity type.

16. The method of claim 11, wherein each of the collaborating computers and a user of that collaborating computer are an endpoint and wherein the identification information comprises an identification code for identifying data to which a first data change request pertains.

17. The method of claim 16, wherein the sequence number information and dependency information are arranged in a data change request substantially in the form:

sequence number 1 @ endpoint 1;

sequence number 2 @ endpoint 2, wherein the sequence number 1 is the sequence of the data change request, the endpoint 1 is the endpoint from which the data change request was generated, the sequence number 2 is the sequence number of the prior data change request and the endpoint 2 is the endpoint from which the prior data change request was generated.

18. The method of claim 11 wherein each data change request comprises a header portion and a payload portion and wherein step (a) comprises inserting the priority information into a header portion of a data change request.

19. The method of claim 11 wherein each data change request comprises a header portion and a payload portion and wherein step (b) comprises inserting the dependency information into a header portion of a data change request.

20. The method of claim 11 wherein each of the collaborating computers and a user of that collaborating computer comprise a unique endpoint.

21. The method of claim 20 wherein step (b) comprises resolving a dependency collision between first and second data change requests based on an order in which endpoints that generated the first and second data change requests joined the collaboration session.

22. A computer program product for formatting data change requests in a peer-to-peer, activity-based collaboration system having at least two collaborating computers, each with a local copy of data thereon and wherein the collaborating computers exchange data change requests during a collaboration session for effecting changes to the local copies of data for collaborative activities, the computer program product comprising a computer readable medium for storing computer readable program code thereon, including:

program code for inserting into each data change request priority information that determines an order of execution of data change requests; and

program code for inserting into selected data change requests dependency information for resolving a dependency collision between first and second data change requests which both depend for execution on a third data change request,

wherein the dependency information comprises, for a data change request;

an identification of data to which the data change request pertains;

endpoint information identifying an endpoint from which the data change request was generated;

a data change request sequence number for the data change request; and

information identifying an endpoint and a data change request sequence number for a prior data change request on which the data change request depends.

23. The computer program product of claim 22 wherein each of the collaborating computers and a user of that collaborating computer are an endpoint and wherein the data change request sequence number comprises a sequence number generated by an endpoint that generated that data change request.

24. The computer program product of claim 22, wherein each of the collaborating computers and a user of that collaborating computer are an endpoint and wherein the dependency information in a data change request comprises characteristics of an endpoint that originated that data change request for use in resolving dependency collisions between that data change request and another data change request on the basis of, at least in part, the endpoint characteristics.

25. The computer program product of claim 22, wherein the dependency information comprises a type of data change for use in resolving dependency collisions between a first data change request and a second data change request on the basis of, at least in part, the data change type.

26. The computer program product of claim 22, wherein the dependency information comprises a type of activity for use in resolving dependency collisions between a first data change request and a second data change request on the basis of, at least in part, the data change type.

27. The computer program product of claim 22, wherein each of the collaborating computers and a user of that collaborating computer are an endpoint and wherein the identification information comprises an identification code for identifying data to which a first data change request pertains.

28. The computer program product of claim 27, wherein the sequence number information and dependency information are arranged in a data change request substantially in the form:

sequence number 1 @ endpoint 1;

sequence number 2 @ endpoint 2, wherein the sequence number 1 is the sequence of the data change request, the endpoint 1 is the endpoint from which the data change request was generated, the sequence number 2 is the sequence number of the prior data change request and the endpoint 2 is the endpoint from which the prior data change request was generated.

29. The computer program product of claim 22 wherein each data change request comprises a header portion and a payload portion and wherein the program code for inserting into each data change request priority information that determines an order of execution of data change requests comprises program code for inserting the priority information into a header portion of a data change request.

30. The computer program product of claim 22 wherein each data change request comprises a header portion and a payload portion and wherein the program code for inserting into selected data change requests dependency information for resolving a dependency collision comprises program code for inserting the dependency information into a header portion of a data change request.

31. The computer program product of claim 22 wherein each of the collaborating computers and a user of that collaborating computer comprise a unique endpoint.

32. The computer program product of claim 31 wherein the program code for inserting into selected data change requests dependency information for resolving a dependency collision comprises program code for resolving a dependency collision between first and second data change requests based on an order in which endpoints that generated the first and second data change requests joined the collaboration session.