Method for synchronizing and archiving information between computer systems

• US 5,710,922 A
• Filed: 12/18/1995
• Issued: 01/20/1998
• Est. Priority Date: 06/02/1993
• Status: Expired due to Term

• Current Assignee: Apple Inc.
• Original Assignee: Apple Computer Incorporated (Apple Inc.)
• Inventors: Smith, Walter R., Alley, Peter E.
• Primary Examiner(s): Black, Thomas G.
• Assistant Examiner(s): Alam, Hosain T.
• Application Number:
  US08/575,013
• Time in Patent Office: 764 Days
• Field of Search: 395/618, 395/619, 395/617, 395/182.18, 395/235, 395/239, 395/242, 395/243, 395/200.03, 395/608
• US Class Current: 1/1
• CPC Class Codes: G06F 16/273 Asynchronous replication or reconciliation
• CPC Class Codes: G06F 9/52 Program synchronisation; Mutual exclusion, e.g. by means of semaphores
• CPC Class Codes: Y10S 707/99952 Coherency, e.g. same view to multiple users
• CPC Class Codes: Y10S 707/99953 Recoverability

Abstract

A method for synchronizing the data between two separate computer systems is described. In a first aspect of the invention, the method includes the step of identifying each record stored in the memory of the first computer system that is intended to be synchronized. The records are identified with a unique identification indicia and an indicia that indicates the last time that the record was altered. Using the time of the last synchronization information, each of the selected records that was added to or deleted from one of the computer systems since the last synchronization is identified and added to or deleted from the other computer system. Further, each of the records that was modified on one computer system is modified on the other. If conflicting actions have occurred on the two computer systems, then the conflicts are handled in accordance with a predetermined protocol. In a preferred aspect, a synchronization list is created that identifies each of these additions, deletions and modifications and either prioritizes them in accordance with the protocol or informs the user of the conflicts.

Claims

1. A method for synchronizing data records stored in a first computer system with corresponding data records stored in a second computer system, each computer system having memory capable of storing a multiplicity of selected records that are intended to be synchronized, the method comprising the steps of:

identifying each record stored in the memory of the first computer system that is intended to be synchronized with a unique identification indicia and an indicia that indicates a time when the record was last altered;

initiating communication between the first computer system and the second computer system;

identifying to the second computer system a name indicator of the first computer system that is intended to be synchronized;

determining the last time that the records of the first computer system were synchronized with the second computer system in accordance with the name indicator of the first computer system;

identifying each of the selected records that was deleted on the first computer system since last synchronized with the second computer system and for each such deleted record on the first computer system, deleting the corresponding record from the second computer system;

identifying each of the selected records that was added to the first computer system since last synchronized with the second computer system and for each record that was added to the first computer system, copying such new record to the second computer system to create a corresponding record in the second computer system;

identifying each of the selected records in the first computer system that both has a corresponding record in the second computer system and was modified on the first computer system since last synchronized; and

synchronizing the modified records between the first and second computer system;

wherein said record deleting step, said record adding step and said modified record synchronizing step cooperate to synchronize the records stored in the first computer system with records stored in the second computer system,

wherein the second computer system is capable of synchronizing with a plurality of different first computer systems that may each have different data, and

wherein said identifying of the first computer system that is intended to be synchronized is selected from the plurality of different first computer systems based on the name indicators for each of the plurality of different first computer systems, each of the name indicators being a unique indicia.

2. A method as recited in claim 1 further comprising the step of:

identifying each of the selected records that was added to the second computer system since last synchronized and adding such selected new records to the first computer system; and

giving a unique identifying identification indicia to each said selected new record during the synchronization process to insure that duplicate identification indicia are not given to separate records which originate in the first and second computer systems, respectively.

3. A method as recited in claim 1 wherein the modified record synchronizing step includes the substeps of:

for each particular modified record in the first computer system, checking to determine whether an associated corresponding record in the second computer system has been modified; and

wherein when the associated corresponding record has not been modified, the associated corresponding record is replaced by a copy of the particular modified record in the first computer system.

4. A method as recited in claim 3 wherein in the modified record synchronizing step, when the corresponding record associated with a particular modified record in the first computer system has also been modified in the second computer system, a dialog box is displayed on one of the computer systems asking the user to choose which modified version of the particular record should be retained.

5. A method as recited in claim 1 wherein during the synchronization process, the time of synchronization as determined by the first computer system is stored for future use as the time of last synchronization when the next synchronization between the first and second computer systems is performed.

6. A method as recited in claim 1 wherein the first computer system is capable of synchronizing its records with a plurality of different second computer systems and wherein a value indicative of the time of last synchronization is stored on each second computer system in order to identify the time of last synchronization with that particular second computer system.

7. A method as recited in claim 1 further comprising the step of archiving each corresponding record that is deleted from the second computer system.

8. A method as recited in claim 7 wherein the archived records are stored in the memory of the second computer system.

9. A method as recited in claim 1 wherein not all of the records that are stored in at least one of the first and second computer systems are intended to be synchronized.

10. A method as recited in claim 1 further comprising the step of archiving each record that is deleted from the second computer system during the synchronization process.

11. A method for synchronizing data records stored in a first computer system with corresponding data records stored in a second computer system, each computer system having memory capable of storing a multiplicity of selected records that are intended to be synchronized, the method comprising the steps of:

identifying each record stored in the memory of the first computer system that is intended to be synchronized with a unique identification indicia and an indicia that indicates a time when the record was last altered;

identifying each new record that has been added to the second computer system with a special identification indicia that will be changed when the new record is synchronized;

initiating communication between the first computer system and the second computer system;

identifying to the second computer system a name indicator of the first computer system that is intended to be synchronized;

determining the last time that the records of the first computer system were synchronized with the second computer system in accordance with the name indicator of the first computer system;

creating a synchronization list that identifies each of the selected records that was deleted on the first computer system since last synchronized with the second computer system but still exists on the second computer system, each of the selected records that was deleted on the second computer system since last synchronized with the second computer system but still exists on the first computer system, each of the selected records that was added to the first computer system, and each of the selected records that was added to the second computer system;

modifying the synchronization list; and

using the modified synchronization list to synchronize the first and second computer systems, wherein records that have been deleted on one of the computer systems are generally deleted from the other and records that have been added to one of the computer systems are generally added to the other,

wherein the second computer system is capable of synchronizing with a plurality of different first computer systems that have different name indicators and may each have different data, and

wherein said identifying of the first computer system that is intended to be synchronized is selected from the plurality of different first computer systems based on the name indicators for each of the plurality of different first computer systems.

12. A method as recited in claim 11 wherein the synchronization modification step includes the substeps of adding entries corresponding to the selected records that have been modified on the first computer system to the synchronization list and adding entries corresponding to selected records that have been modified on the second computer system to the synchronization list.

13. A method as recited in claim 12, wherein the synchronization list contains at most one entry for each record.

14. A method as recited in claim 13, wherein when a record has been modified in one of the computer systems and its corresponding record has been deleted in the other, the modified record will be deleted.

15. A method as recited in claim 13, wherein when a record has been modified in both computer systems the user will be informed of the conflict.

16. A method as recited in claim 13, wherein when a record has been modified in one of the computer systems and its corresponding record has been deleted in the other, the user will be informed of the conflict.

17. A method as recited in claim 11 wherein during the synchronization step, any record that was initially added to the second computer system is assigned a new identification indicia by the first computer system when it is added to the first computer system.

18. A method as recited in claim 11 wherein the synchronization list is compiled on the second computer system.

19. A method as recited in claim 11 wherein during the synchronization process, the time of synchronization as determined by the first computer system is stored for future use as the time of last synchronization when the next synchronization between the first and second computer systems is performed.

20. A method as recited in claim 11 wherein the first computer system is capable of synchronizing its records with a plurality of different second computer systems and wherein a value indicative of the time of last synchronization is stored on each second computer system in order to identify the time of last synchronization with that particular second computer system.