Synchronizing replicas of a database

• US 8,132,046 B2
• Filed: 04/07/2010
• Issued: 03/06/2012
• Est. Priority Date: 03/10/2005
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Varghese, John
• Primary Examiner(s): Maskulinski, Michael
• Application Number:
  US12/756,122
• Publication Number:
  US 20100199127A1
• Time in Patent Office: 699 Days
• Field of Search: None
• US Class Current: 714/6.23
• 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 16/273 Asynchronous replication or reconciliation
• CPC Class Codes: H04L 67/1095 Replication or mirroring of data, e.g. scheduling or transport for data synchronisation between network nodes

Abstract

Replicas of a database are synchronized. A failure of update data is detected from a first replica to be applied to a second replica. A cause of the failure is determined. The cause of the failure is resolved. The replicas of the database are synchronized without requiring manual intervention.

Claims

1. A computer-implemented method for synchronizing replicas of a database, the method comprising:

detecting a failure of update data from a first replica of the database at a first server site to be applied to a second replica of the database at a second server site;

determining a cause of the failure;

resolving the cause of the failure by deleting an object if the cause of the failure is due to the object not being deleted during a previous export; and

automatically, without manual intervention, sending the update data to the second replica of the database at the second server site after the cause of the failure is resolved.

2. The computer-implemented method of claim 1, further comprising resending the update data.

3. The computer-implemented method of claim 2, further comprising applying the update data to the second replica.

4. The computer-implemented method of claim 1, wherein the determining comprises determining where the cause of the failure occurred.

5. The computer-implemented method of claim 1, wherein the determining comprises parsing metadata, wherein the parsed metadata indicates if an account is locked out.

6. The computer-implemented method of claim 1, wherein the determining comprises determining if the second replica is up-to-date.

7. The computer-implemented method of claim 1, wherein the determining comprises determining if the failure was due to a packet being lost, wherein the packet contains the update data.

8. The computer-implemented method of claim 7, wherein the resolving comprises requesting for a packet to be resent if the cause of the failure is due to the packet being lost.

9. The computer-implemented method of claim 1, wherein the resolving comprises unlocking an account if the cause of the failure is due to the account being locked out.

10. The computer-implemented method of claim 1, further comprising notifying an appropriate authority of the failure if corrective actions need to be taken by the appropriate authority.

11. The computer-implemented method of claim 1, further comprising recording update data in an operations log.

12. A computer readable medium containing program instructions for synchronizing replicas of a database, the program instructions which when executed by a computer system cause the computer system to execute a method comprising:

detecting a failure of update data from a first replica of the database at a first server site to be applied to a second replica of the database at a second server site;

determining a cause of the failure;

resolving the cause of the failure by deleting an object if the cause of the failure is due to the object not being deleted during a previous export; and

automatically, without manual intervention, sending the update data to the second replica of the database at the second server site after the cause of the failure is resolved.

13. The computer readable medium of claim 12, further comprising program instructions for resending the update data.

14. The computer readable medium of claim 13, further comprising program instructions for applying the update data to the second replica.

15. The computer readable medium of claim 12, wherein the determining comprises program instructions for determining where the cause of the failure occurred.

16. The computer readable medium of claim 12, wherein the determining comprises program instructions for parsing metadata, wherein the parsed metadata indicates if an account is locked out.

17. The computer readable medium of claim 12, wherein the determining comprises program instructions for determining if the second replica is up-to-date.

18. The computer readable medium of claim 12, wherein the determining comprises program instructions for determining if the failure was due to a packet being lost, wherein the packet contains the update data.

19. The computer readable medium of claim 18, wherein the resolving comprises program instructions for requesting for a packet to be resent if the cause of the failure is due to the packet being lost.

20. The computer readable medium of claim 12, wherein the resolving comprises program instructions for unlocking an account if the cause of the failure is due to the account being locked out.

21. The computer readable medium of claim 12, further comprising program instructions for notifying an appropriate authority of the failure if corrective actions need to be taken by the appropriate authority.

22. The computer readable medium of claim 12, further comprising program instructions for recording update data in an operations log.

23. A database system comprising:

a first server site comprising a first replica of a database;

a second server site coupled to the first server site, the second server site comprising a second replica of the database; and

a client coupled to the first replica wherein the client detects a failure of update data from the first replica to be applied to the second replica, wherein the client further determines a cause of the failure and resolves the cause of the failure by deleting an object if the cause of the failure is due to the object not being deleted during a previous export, wherein the client automatically, without manual intervention, sending the update data to the second replica of the database at the second server site after the cause of the failure is resolved.

24. The database system of claim 23, wherein the client resends the update data and applies the update data to the second replica.

25. The database system of claim 23, further comprising a server that fetches metadata for the client.

26. The database system of claim 25, wherein the metadata indicates if an account has been locked out.

27. The database system of claim 25, wherein the metadata indicates if the second replica is up-to-date.

28. The database system of claim 23, further comprising an operations log for recording the update data.