Updateable fan-out replication with reconfigurable master association

• US 20060155778A1
• Filed: 12/02/2005
• Published: 07/13/2006
• Est. Priority Date: 12/03/2004
• Status: Active Grant

• Current Assignee: Oracle International Corporation (Oracle Corporation)
• Original Assignee: Oracle International Corporation (Oracle Corporation)
• Inventors: Sharma, Amit, Zhou, Quan, Shih, Daniel, Srinivasan, Uppili, Venkatasamy, Satishkumar
• Granted Patent: US 7,734,585 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 16/2246 Trees, e.g. B+trees
• 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

Abstract

A system, method, computer program and article of manufacture for updateable fan-out replication with reconfigurable master association in a large, multi-node LDAP environment. A replication ring supports the addition of fan-out nodes as children to each primary node that sits on a replication ring. The fan-out nodes can be cascaded in multiple parent/child relationships and can support full replication or a subset of the parent data. Each child/parent relationship is defined by an agreement. Each fan-out node replicates changes to their immediate children and parent based upon the change details and the configured agreement, distributing the replication load.

Claims

1. A method for replicating LDAP directories in a distributed database system, the distributed database system comprising one or more primary nodes communicating via a replication ring and one or more fan-out nodes, each fan-out node capable of being a child to a primary node or a parent or child to other fan-out nodes, the method comprising:

implementing a change to the LDAP directory received at a fan-out node; and

replicating the change at one or more nodes in the distributed database system based on one or more relationship agreements,

wherein one relationship agreement is configured for each parent/child relationship in the distributed database system.

2. The method of claim 1, wherein each relationship agreement comprises:

a relationship type, the type being uni-directional or bi-directional;

a set of data included in the child replication set; and

a set of rules describing the operations permitted to be propagated between child and parent.

3. The method of claim 1, wherein implementing the change comprises:

creating a change log, the change log comprising change information detailing operation information required to implement the change and origin information detailing the node at which the change originated and the node at which the change log was regenerated; and

modifying the database based on the change log.

4. The method of claim 3, wherein replicating the change comprises:

determining if the change is to be propagated to one or more fan-out nodes; and

regenerating the change log if the change is to be propagated to one or more fan-out nodes.

5. The method of claim 4, wherein determining if the change is to be propagated to one or more fan-out nodes comprises:

determining if the change is to be propagated to one or more child nodes; and

determining if the change is to be propagated to a parent node.

6. The method of claim 5, wherein determining if the change is to be propagated to one or more child nodes comprises:

comparing origin information of the change log to a node under consideration;

comparing operation information of the change log to a relationship agreement of the node under consideration and its parent to determine if the operation is permitted;

propagating the change to the node under consideration if the origin information indicates that the change did not come from the child and if the operation is permitted.

7. The method of claim 5, wherein determining if the change is to be propagated to the parent node comprises:

determining that the relationship to the parent is bi-directional; and

determining that the operation information of the change log is permitted by the relationship agreement.

8. The method of claim 5, further comprising:

if the change is to be propagated to the parent node, replaying the change at the parent.

9. The method of claim 1 further comprising:

re-associating a child node to a new master.

10. The method of claim 9, wherein re-associating a child node to a new master comprises:

if the child'"'"'s original master is a primary node, re-associating the child node to another primary node; and

if the child'"'"'s original master is not a primary node, re-associating the child node to the parent of its original master.

11. A computer-readable medium containing instructions thereon, the instructions being executable by a computer to cause the computer to perform a method for replicating LDAP directories in a distributed database system, the distributed database system comprising one or more primary nodes communicating via a replication ring and one or more fan-out nodes, each fan-out node capable of being a child to a primary node or a parent or child to other fan-out nodes, the method comprising:

implementing a change to the LDAP directory received at a fan-out node; and

replicating the change at one or more nodes in the distributed database system based on one or more relationship agreements,

wherein one relationship agreement is configured for each parent/child relationship in the distributed database system.

12. The computer-readable medium of claim 11, wherein each relationship agreement comprises:

a relationship type, the type being uni-directional or bi-directional;

a set of data included in the child replication set; and

a set of rules describing the operations permitted to be propagated between child and parent.

13. The computer-readable medium of claim 11, wherein implementing the change comprises:

creating a change log, the change log comprising change information detailing operation information required to implement the change and origin information detailing the node at which the change originated and the node at which the change log was regenerated; and

modifying the database based on the change log.

14. The computer-readable medium of claim 13, wherein replicating the change comprises:

determining if the change is to be propagated to one or more fan-out nodes; and

regenerating the change log if the change is to be propagated to one or more fan-out nodes.

15. The computer-readable medium of claim 14, wherein determining if the change is to be propagated to one or more fan-out nodes comprises:

determining if the change is to be propagated to one or more child nodes; and

determining if the change is to be propagated to a parent node.

16. The computer-readable medium of claim 15, wherein determining if the change is to be propagated to one or more child nodes comprises:

comparing origin information of the change log to a node under consideration;

comparing operation information of the change log to a relationship agreement of the node under consideration and its parent to determine if the operation is permitted;

propagating the change to the node under consideration if the origin information indicates that the change did not come from the child and if the operation is permitted.

17. The computer-readable medium of claim 15, wherein determining if the change is to be propagated to the parent node comprises:

determining that the relationship to the parent is bi-directional; and

determining that the operation information of the change log is permitted by the relationship agreement.

18. The computer-readable medium of claim 15, further comprising:

if the change is to be propagated to the parent node, replaying the change at the parent.

19. The computer-readable medium of claim 11 further comprising:

re-associating a child node to a new master.

20. The computer-readable medium of claim 19, wherein re-associating a child node to a new master comprises:

if the child'"'"'s original master is a primary node, re-associating the child node to another primary node; and

if the child'"'"'s original master is not a primary node, re-associating the child node to the parent of its original master.