Transactional replication

Patent metadata

Field	Value
Publication number	US-9317545-B2
Application number	US-201313955487-A
Country	US
Kind code	B2
Filing date	Jul 31, 2013
Priority date	Sep 21, 2005
Publication date	Apr 19, 2016
Grant date	Apr 19, 2016

Abstract

Writing data in a distributed database having a plurality of nodes is disclosed. Writing includes receiving a write request at a node, wherein the write request is associated with one or more operations to define an atomic transaction and performing the atomic transaction based on the request. The atomic transaction includes writing to a first version of the database in the node and writing to an entity representative of a state of the first version of the database.

First claim

What is claimed is:

1. A method of writing data in a distributed database having a plurality of nodes, comprising:
receiving a write request at a first member node having a first version of a database;
applying the received original write request to both the first version of the database and a journal queue in a single atomic transaction using a processor, comprising:
placing the received write request in the journal, queue of the first member node, wherein the journal queue is associated with the first member node and is configured to store write requests that have not yet been reconciled with a master version of the database on a master node;

propagating one or more items in the journal queue to the master node;
determining whether a conflict exists between the first version of the database with the write request applied and a master version of the database;
in the event that a conflict exists, reconciling a write request with the master version of the database; and
in the event that a conflict does not exist:
determining that the first version of the database is in a high availability pair, wherein the high availability pair includes a second version of the database in a second member node; and
applying the received original write request to both the first version of the database and to the second version of the database in the second member node.

2. The method of claim 1 , wherein the write request comprises a semantically expressed request to modify the database without sending changed data.

3. The method of claim 1 , wherein the write request includes one or more selected from the group consisting of commands, operations, and instructions.

4. The method of claim 1 , wherein the first member node is an active node and the second member node is a passive node in the high availability pair.

5. The method of claim 1 , wherein the second member node is associated with a second journal queue and further including applying the write request to the second version of the database and to the second journal queue in a single atomic transaction.

6. The method of claim 1 , further comprising:
receiving from the master node an indication that the one or more items in the journal queue have been reconciled with the master version of the database by the master node.

7. The method of claim 1 , further comprising:
receiving from the master node an indication that the one or more items in the journal queue have been reconciled with the master version of the database by the master node; and
in response to receiving the indication, removing the one or more items from the journal queue.

8. The method of claim 1 , further comprising:
receiving from the master node an indication that the one or more items in the journal queue have been reconciled with the master version of the database by the master node, wherein the indication indicates whether data in the master version of the database conflicts with the one or more items in the journal queue.

9. The method of claim 1 , further comprising:
receiving from the master node an indication that the one or more items in the journal queue have been reconciled with the master version of the database by the master node; and
in the event that the indication indicates a conflict between data in the master version of the database and the one or more items in the journal queue, resolving the conflict.

10. The method of claim 1 , further comprising:
receiving from the master node an indication that the one or more items in the journal queue have been reconciled with the master version of the database by the master node; and
in the event that the indication indicates a conflict between data in the master version of the database and the one or more items in the journal queue, resolving the conflict, wherein removing the one or more items from the journal queue and resolving the conflict are performed in a single atomic transaction.

11. A computer program product for writing data in a distributed database having a plurality of nodes, the computer program product being embodied in a tangible computer readable storage medium and comprising computer instructions for:
receiving a write request at a first member node having a first version of a database;
applying the received original write request to both the first version of the database and a journal queue in a single atomic transaction, comprising:
placing the write request in the journal, queue of the first member node, wherein the journal queue is associated with the first member node and is configured to store write requests that have not yet been reconciled with a master version of the database on a master node;

propagating one or more items in the journal queue to the master node;
determining whether a conflict exists between the first version of the database with the write request applied and a master version of the database;
in the event that a conflict exists, reconciling a write request with the master version of the database; and
in the event that a conflict does not exist:
determining that the first version of the database is in a high availability pair, wherein the high availability pair includes a second version of the database in a second member node; and
applying the received original write request to both the first version of the database and to the second version of the database in the second member node.

12. The computer program product recited in claim 11 , wherein the write request comprises a semantically expressed request to modify the database without sending changed data.

13. The computer program product recited in claim 11 , wherein the write request includes one or more selected from the group consisting of commands, operations, and instructions.

14. The computer program product recited in claim 11 , wherein the first member node is an active node and the second member node is a passive node in the high availability pair.

15. The computer program product recited in claim 11 , wherein the second member node is associated with a second journal queue and further including applying the write request to the second version of the database and to the second journal queue in a single atomic transaction.

16. The computer program product recited in claim 11 , further comprising computer instructions for:
receiving from the master node an indication that the one or more items in the journal queue have been reconciled with the master version of the database by the master node.

17. The computer program product recited in claim 11 , further comprising computer instructions for:
receiving from the master node an indication that the one or more items in the journal queue have been reconciled with the master version of the database by the master node; and
in response to receiving the indication, removing the one or more items from the journal queue.

18. The computer program product recited in claim 11 , further comprising computer instructions for:
receiving from the master node an indication that the one or more items in the journal queue have been reconciled with the master version of the database by the master node, wherein the indication indicates whether data in the master version of the database conflicts with the one or more items in the journal queue.

19. The computer program product recited in claim 11 , further comprising computer instructions for:
receiving from the master node an indication that the one or more items in the journal queue have been reconciled with the master version of the database by the

Assignees

• Infoblox Inc

Inventors

• Bailey Stuart M
• Pulleyn Ivan W
• Gutti Srinath

Classifications

• G06F17/30309 Primary

  Physics · mapped topic

• G06F17/30575

  Physics · mapped topic

• G06F17/30923

  Physics · mapped topic

• G06F16/219 Primary

  Managing data history or versioning (querying versioned data G06F16/2474; querying temporal data G06F16/2477) · CPC title

• G06F16/27

  Replication, distribution or synchronisation of data between databases or within a distributed database system; Distributed database system architectures therefor · CPC title