Method and system for data replication

• US 6,615,223 B1
• Filed: 02/29/2000
• Issued: 09/02/2003
• Est. Priority Date: 02/29/2000
• Status: Expired due to Term

• Current Assignee: Oracle International Corporation (Oracle Corporation)
• Original Assignee: Oracle International Corporation (Oracle Corporation)
• Inventors: Shih, Kuang-Yu, Srinivasan, Uppili
• Primary Examiner(s): Robinson, Greta
• Assistant Examiner(s): RAYYAN, SUSAN F
• Application Number:
  US09/515,680
• Time in Patent Office: 1,281 Days
• Field of Search: 707/10, 707/203, 707/204, 707/202, 707/101, 709/201, 709/101
• US Class Current: 707/625
• 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 16/275 Synchronous replication
• CPC Class Codes: Y10S 707/99952 Coherency, e.g. same view to multiple users
• CPC Class Codes: Y10S 707/99953 Recoverability

Abstract

A method and mechanism for data replication is disclosed. One embodiment of the invention relates to an efficient and effective replication system using LDAP replication components. Another embodiment of the invention pertains to a schema and format independent method for data replication. Procedures for adding, deleting, and modifying replicated data, and for replicating conflict resolution are also disclosed. A further embodiment of the invention is directed to improved methods and mechanisms for adding and removing nodes from a replication system.

Claims

1. A process for database replication comprising:

receiving a change request to modify data at a first replication site;

implementing said change request at said first replication site;

generating a change record corresponding to said change request;

said change record having a schema independent format;

sending said change record to a second replication site; and

implementing said change record to a copy of said data at said second replication site.

2. The process of claim 1 in which said change request is directed to LDAP directory data.

3. The process of claim 1 in which implementing said change record at said replication site comprises:

generating a database instruction that is specific to schema and data organizations at said second replication site.

4. The process of claim 3 further comprising:

accessing metadata at said second replication site to generate said database instruction.

5. The process of claim 1 further comprising copying said change record to a first replication log at said first replication site, in which sending said change record to said second replication site comprises replicating said change record from said first replication log to a second replication log at said second replication site.

6. The process of claim 1 in which implementing said change record at said second replication site is performed using synchronous replication.

7. The process of claim 6 further comprising:

adding said change record to a change log at said first replication site; and

monitoring said change log for entry of new change records.

8. The process of claim 6 further comprising:

adding said change record to a second change log at said second replication site; and

monitoring said second change log for entry of new change records.

9. The process of claim 1 in which implementing said change record at said second replication site is performed using asynchronous replication.

10. The process of claim 9 in which said change record is sent to said second replication site in a periodic manner.

11. The process of claim 9 in which said change record is sent to said second replication site upon a trigger event.

12. The process of claim 1 in which schema and data organizations of said first replication site is different than that of said second replication site.

13. A process for replication of LDAP directory data in a distributed LDAP environment, comprising:

receiving an LDAP operation request at a first LDAP server, said first LDAP server located at a first LDAP site;

implementing said LDAP operation request to LDAP directory data at said first LDAP site;

generating a change log entry to a change log, said change log entry independent of schema and data organizations at said first LDAP site, said change log entry corresponding to said LDAP operation request;

replicating said change log entry to a second change log at a second LDAP site; and

utilizing said change log entry at said second change log to implement said LDAP operation request at said second LDAP site.

14. The process of claim 13 in which said schema and data organizations of said first replication site is different than that of said second replication site.

15. The process of claim 13 in which implementing said LDAP operation request to said second LDAP site comprises:

generating a database instruction that is specific to schema and data organizations at said second LDAP site.

16. The process of claim 15 further comprising:

accessing metadata at said second LDAP site to generate said database instruction.

17. The process of claim 13 in which replicating said change log entry comprises:

copying said change log entry from said change log to a first replication log at said first LDAP site; and

replicating said change log entry from said first replication log at said first LDAP site to a second replication log at said second LDAP site.

18. The process of claim 13 in which said LDAP directory data is synchronously replicated.

19. The process of claim 14 further comprising:

monitoring said change log for addition of said change log entry.

20. The process of claim 13 in which said LDAP directory data is asynchronously replicated.

21. The process of claim 20 in which said change log entry is replicated to said second LDAP site in a periodic manner.

22. The process of claim 20 in which said change log entry is sent to said second LDAP site upon a trigger event.

23. A computer program product that includes a medium usable by a processor, the medium having stored thereon a sequence of instructions which, when executed by said processor, causes said processor to execute a process for database replication, said process comprising:

receiving a change request to modify data at a first replication site;

implementing said change request at said first replication site;

generating a change record corresponding to said change request;

said change record having a schema independent format;

sending said change record to a second replication site; and

implementing said change record to a copy of said data at said second replication site.

29. The computer program product of claim 23, wherein said process further comprises:

copying said change record to a first replication log at said first replication site, in which sending said change record to said second replication site comprises replicating said change record from said first replication log to a second replication log at said second replication site.

30. The computer program product of claim 23, wherein implementing said change record at said second replication site is performed using synchronous replication.

31. The computer program of claim 30, wherein said process further comprises:

adding said change record to a change log at said first replication site; and

monitoring said change log for entry of new change records.

32. The computer program product of claim 30, wherein said process further comprises:

adding said change record to a second change log at said second replication site; and

monitoring said second change log for entry of new change records.

24. A computer program product that includes a medium usable by a processor, the medium having stored thereon a sequence of instructions which, when executed by said processor, causes said processor to execute a process for replication of LDAP directory data in a distributed LDAP environment, said process comprising:

receiving an LDAP operation request at a first LDAP server, said first LDAP server located at a first LDAP site;

implementing said LDAP operation request to LDAP directory data at said first LDAP site;

generating a change log entry to a change log, said change log entry independent of schema and data organizations at said first LDAP site, said change log entry corresponding to said LDAP operation request;

replicating said change log entry to a second change log at a second LDAP site; and

utilizing said change log entry at said second change log to implement said LDAP operation request at said second LDAP site.

33. The compute program product of claim 24, wherein said schema and data organizations of said first replication site is different than that of said second replication site.

34. The computer program product of claim 24, wherein implementing said LDAP operation request to said second LDAP site comprises:

generating a database instruction that is specific to schema and data organizations at said second LDAP site.

35. The computer program product of claim 34, wherein said process further comprises:

accessing metadata at said second LDAP site to generate said database instruction.

36. The computer program product of claim 24, wherein replicating said change log entry comprises:

copying said change log entry from said change log to a first replication log at said first LDAP site; and

replicating said change log entry from said first replication log at said first LDAP site to a second replication log at said second LDAP site.

37. The computer program product of claim 24, wherein said LDAP directory data is synchronously replicated.

38. The computer program product of claim 37, wherein said process further comprises:

monitoring said change log for addition of said change log entry.

25. A process for database replication comprising:

receiving a change request to modify data at a first replication site;

implementing the change request at the first replication site;

translating the change request into a schema independent change record;

sending the schema independent change record to a second replication site; and

implementing the schema independent change record to a copy of the data at the second replication site.

26. The process of claim 25 wherein implementing the schema independent change record comprises issuing a change instruction that is specific to schema and data organization at the second replication site.

27. The process of claim 26 wherein implementing the schema independent change record further comprises accessing metadata at the second replication site to generate the change instruction.

28. The process of claim 25 further comprising copying the change record to a first replication log at the first replication site, wherein sending the schema independent change record to a second replication comprises replicating the schema independent change record from the first replication log to a second replication log at the second replication site.