Configurable conflict resolution in a computer implemented distributed database

• US 5,806,074 A
• Filed: 03/19/1996
• Issued: 09/08/1998
• Est. Priority Date: 03/19/1996
• Status: Expired due to Term

• Current Assignee: Oracle International Corporation (Oracle Corporation)
• Original Assignee: Oracle Corporation
• Inventors: Souder, Benny, Downing, Alan, Doo, Lip Boon
• Primary Examiner(s): AMSBURY, WAYNE P
• Application Number:
  US08/618,507
• Time in Patent Office: 903 Days
• Field of Search: 395/617, 707/201
• US Class Current: 1/1
• CPC Class Codes: G06F 11/2035 without idle spare hardware
• CPC Class Codes: G06F 11/2048 where the redundant components share neither address space nor persistent storage
• CPC Class Codes: G06F 11/2097 maintaining the standby controller/processing unit updated initialisation or re-synchronisation thereof G06F11/1658 and subgroups
• CPC Class Codes: G06F 16/2308 Concurrency control transaction processing G06F9/466
• CPC Class Codes: G06F 16/2315 Optimistic concurrency control
• CPC Class Codes: G06F 16/2322 using timestamps
• 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: G06F 2201/80 Database-specific techniques
• CPC Class Codes: Y10S 707/99952 Coherency, e.g. same view to multiple users
• CPC Class Codes: Y10S 707/99953 Recoverability

Abstract

An apparatus and method for providing adaptable and configurable conflict resolution within a replicated data environment is disclosed. In a distributed database system having a first node and a second node, the first node including a first data structure, the second node including a second data structure, a configurable conflict resolution apparatus is disclosed as comprising; 1) a conflict detection module for detecting a conflicting modification to corresponding portions of the first and the second data structures; 2) a plurality of conflict resolution methods, one or more of the plurality of conflict resolution methods being configurably associated with the corresponding portions of the first and the second data structures; and 3) a conflict resolution module for activating a first conflict resolution method of the one or more of the plurality of conflict resolution methods when the conflict detection module detects the conflicting modification to the corresponding portions of the first and the second data structures.

Claims

1. In a distributed database system having a first replica of a data structure and a second replica of said data structure, a configurable conflict resolution apparatus comprising:

a conflict detection module for detecting a conflicting modification to corresponding portions of said first and said second replicas;

a plurality of conflict resolution methods, one or more of said plurality of conflict resolution methods being configurably associated with said corresponding portions of said first and said second replicas; and

a conflict resolution module for activating a first conflict resolution method of said one or more of said plurality of conflict resolution methods when said conflict detection module detects said conflicting modification to said corresponding portions of said first and said second replicas.

2. The configurable conflict resolution apparatus as claimed in claim 1 wherein said conflict resolution module further includes processing logic for determining if said first conflict resolution method successfully resolved said conflicting modification.

3. The configurable conflict resolution apparatus as claimed in claim 2 wherein said conflict resolution module further includes processing logic for activating a second conflict resolution module if said first conflict resolution method was not successful in resolving said conflicting modification.

4. The configurable conflict resolution apparatus as claimed in claim 2 wherein said conflict resolution module further includes processing logic for activating each of said one or more of said plurality of conflict resolution methods until one or more of said conflict resolution methods is successful in resolving said conflicting modification or until all conflict resolution methods have been tried at least once.

5. The configurable conflict resolution apparatus as claimed in claim 4 wherein said conflict resolution module further includes processing logic for storing non-conflicting values in said corresponding portions of said first and said second replicas if one of said conflict resolution methods was successful in resolving said conflicting modification.

6. The configurable conflict resolution apparatus as claimed in claim 5 further including a means for deferring storing of non-conflicting values until after a complete portion of said first and said second replicas is checked for other conflicting modifications.

7. The configurable conflict resolution apparatus as claimed in claim 4 wherein said conflict resolution module further includes processing logic for logging an error if none of said conflict resolution methods was successful in resolving said conflicting modification.

8. The configurable conflict resolution apparatus as claimed in claim 4 wherein a priority is assigned to each of said plurality of conflict resolution methods and said conflict resolution module activates each of said plurality of conflict resolution methods in priority order.

9. The configurable conflict resolution apparatus as claimed in claim 1 wherein at least one of said plurality of conflict resolution methods is registered by a user.

10. The configurable conflict resolution apparatus as claimed in claim 1 wherein at least one of said plurality of conflict resolution methods is a minimum value method.

11. The configurable conflict resolution apparatus as claimed in claim 1 wherein at least one of said plurality of conflict resolution methods is a maximum value method.

12. The configurable conflict resolution apparatus as claimed in claim 1 wherein at least one of said plurality of conflict resolution methods is an earliest timestamp method.

13. The configurable conflict resolution apparatus as claimed in claim 1 wherein at least one of said plurality of conflict resolution methods is a priority group method.

14. The configurable conflict resolution apparatus as claimed in claim 1 wherein at least one of said plurality of conflict resolution methods is a site priority method.

15. The configurable conflict resolution apparatus as claimed in claim 1 wherein at least one of said plurality of conflict resolution methods is an overwrite method.

16. The configurable conflict resolution apparatus as claimed in claim 1 wherein at least one of said plurality of conflict resolution methods is a discard method.

17. The configurable conflict resolution apparatus as claimed in claim 1 wherein at least one of said plurality of conflict resolution methods is an average value method.

18. The configurable conflict resolution apparatus as claimed in claim 1 wherein at least one of said plurality of conflict resolution methods is an additive value method.

19. The configurable conflict resolution apparatus as claimed in claim 1 wherein said conflicting modification is an update conflict.

20. The configurable conflict resolution apparatus as claimed in claim 1 wherein said conflicting modification is a uniqueness conflict.

21. The configurable conflict resolution apparatus as claimed in claim 1 wherein said conflicting modification is a delete conflict.

22. The configurable conflict resolution apparatus as claimed in claim 1 further including audit logic for automatically generating and maintaining audit information in a shadow data structure.

23. The configurable conflict resolution apparatus as claimed in claim 1 further including recursion logic for recursively activating said first conflict resolution method until no further modifications to said corresponding portions of said first and second replicas is detected.

24. In a distributed database system having a first replica of a data structure and a second replica of said data structure, a method for configurable conflict resolution comprising the steps of:

detecting a conflicting modification to corresponding portions of said first and said second replicas;

providing a plurality of conflict resolution methods, one or more of said plurality of conflict resolution methods being configurably associated with said corresponding portions of said first and said second replicas; and

activating a first conflict resolution method of said one or more of said plurality of conflict resolution methods when said conflicting modification is detected in said detecting step.

25. For use in a distributed database system having a first replica of a data structure and a second replica of said data structure, an article of manufacture comprising a computer usable mass storage medium having computer readable program code embodied therein for causing a processing means to perform configurable conflict resolution, said computer readable program code in said article of manufacture comprising:

a conflict detection module for causing said processing means to detect a conflicting modification to corresponding portions of said first and said second replicas;

a plurality of conflict resolution methods, one or more of said plurality of conflict resolution methods being configurably associated with said corresponding portions of said first and said second replicas; and

a conflict resolution module for causing said processing means to activate a first conflict resolution method of said one or more of said plurality of conflict resolution methods when said conflict detection module detects said conflicting modification to said corresponding portions of said first and said second replicas.

26. The article of manufacture as claimed in claim 25 wherein said conflict resolution module further includes a processing logic code segment for determining if said first conflict resolution method successfully resolved said conflicting modification.

27. The article of manufacture as claimed in claim 26 wherein said conflict resolution module further includes a processing logic code segment for activating a second conflict resolution module if said first conflict resolution module was not successful in resolving said conflicting modification.

28. The article of manufacture as claimed in claim 26 wherein said conflict resolution module further includes a processing logic code segment for activating each of said one or more of said plurality of conflict resolution methods until one or more of said conflict resolution methods is successful in resolving said conflicting modification or until all conflict resolution methods have been tried at least once.

29. The article of manufacture as claimed in claim 28 wherein said conflict resolution module further includes a processing logic code segment for storing non-conflicting values in said corresponding portions of said first and said second replicas if one of said conflict resolution methods was successful in resolving said conflicting modification.

30. The article of manufacture as claimed in claim 29 further including a means for deferring storing of non-conflicting values until after a complete portion of said first and said second replicas is checked for other conflicting modifications.

31. The article of manufacture as claimed in claim 28 wherein said conflict resolution module further includes a processing logic code segment for logging an error if none of said conflict resolution methods was successful in resolving said conflicting modification.

32. The article of manufacture as claimed in claim 25 wherein at least one of said plurality of conflict resolution methods is registered by a user.

33. In a distributed database system having a first replica of a data structure and a second replica of the same data structure, a configurable conflict resolution apparatus comprising:

conflict detection means for detecting a conflicting modification to corresponding portions of said first and said second replicas;

a plurality of conflict resolution means, one or more of said plurality of conflict resolution means being configurably associated with said corresponding portions of said first and said second replicas; and

activation means for activating a first conflict resolution means of said one or more of said plurality of conflict resolution means when said conflict detection means detects said conflicting modification to said corresponding portions of said first and said second replicas.

34. The configurable conflict resolution apparatus as claimed in claim 33 wherein said conflict resolution means further includes processing logic for determining if said first conflict resolution means successfully resolved said conflicting modification.

35. The configurable conflict resolution apparatus as claimed in claim 34 wherein said conflict resolution means further includes processing logic for activating a second conflict resolution means if said first conflict resolution means was not successful in resolving said conflicting modification.

36. The configurable conflict resolution apparatus as claimed in claim 34 wherein said conflict resolution means further includes processing logic for activating each of said one or more of said plurality of conflict resolution means until one or more of said conflict resolution means is successful in resolving said conflicting modification or until all conflict resolution means have been tried at least once.

37. The configurable conflict resolution apparatus as claimed in claim 36 wherein said conflict resolution means further includes processing logic for storing non-conflicting values in said corresponding portions of said first and said second replicas if one of said conflict resolution means was successful in resolving said conflicting modification.

38. The configurable conflict resolution apparatus as claimed in claim 37 further including a means for deferring storing on non-conflicting values until after a complete portion of said first and said second replicas are checked for other conflicting modifications.

39. The configurable conflict resolution apparatus as claimed in claim 36 wherein said conflict resolution means further includes processing logic for logging an error if none of said conflict resolution means was successful in resolving said conflicting modification.

40. The configurable conflict resolution apparatus as claimed in claim 33 wherein at least one of said plurality of conflict resolution means is registered by a user.

41. A computer data signal embodied in a carrier wave comprising:

a conflict detection code segment for detecting a conflicting modification to corresponding portions of a first replica and a second replica of a data structure in a distributed database system;

a plurality of conflict resolution method code segments, one or more of said plurality of conflict resolution code segments being configurably associated with said corresponding portions of said first and said second replicas; and

a conflict resolution module code segment for activating a first conflict resolution code segment of said one or more of said plurality of conflict resolution code segments when said conflict detection code segment detects said conflicting modification to said corresponding portions of said first and said second replicas.

42. The computer data signal embodied in a carrier wave as claimed in claim 41 wherein said conflict resolution module code segment further includes a processing logic code segment for determining if said first conflict resolution method code segment successfully resolved said conflicting modification.

43. The computer data signal embodied in a carrier wave as claimed in claim 42 wherein said conflict resolution module code segment further includes a processing logic code segment for activating a second conflict resolution module code segment if said first conflict resolution module code segment was not successful in resolving said conflicting modification.

44. The computer data signal embodied in a carrier wave as claimed in claim 42 wherein said conflict resolution module code segment further includes a processing logic code segment for activating each of said one or more of said plurality of conflict resolution method code segments until one or more of said conflict resolution method code segments is successful in resolving said conflicting modification or until all conflict resolution method code segments have been tried at least once.

45. The computer data signal embodied in a carrier wave as claimed in claim 44 wherein said conflict resolution module code segment further includes a processing logic code segment for storing non-conflicting values in said corresponding portions of said first and said second replicas if one of said conflict resolution method code segments was successful in resolving said conflicting modification.

46. The computer data signal embodied a carrier wave as claimed in claim 45 further including a means for deferring storing of non-conflicting values until after a complete portion of said first and said second replicas is checked for other conflicting modifications.

47. The computer data signal embodied in a carrier wave as claimed in claim 44 wherein said conflict resolution module code segment further includes a processing logic code segment for logging an error if none of said conflict resolution method code segments was successful in resolving said conflicting modification.

48. The computer data signal embodied in a carrier wave as claimed in claim 41 wherein at least one of said plurality of conflict resolution method code segments is registered by a user.