Repeatable message streams for message queues in distributed systems

• US 20060168080A1
• Filed: 07/29/2005
• Published: 07/27/2006
• Est. Priority Date: 12/30/2004
• Status: Active Grant

• Current Assignee: Oracle International Corporation (Oracle Corporation)
• Original Assignee: Oracle International Corporation (Oracle Corporation)
• Inventors: Meiyyappan, Krishnan, Surlaker, Kapil, Bhatt, Neerja
• Granted Patent: US 7,818,386 B2
• Time in Patent Office: Days
• US Class Current: 709/207
• CPC Class Codes: H04L 1/1874 Buffer management
• CPC Class Codes: H04L 2001/0093 Point-to-multipoint
• CPC Class Codes: H04L 49/90 Buffering arrangements

Abstract

Techniques for propagating messages in a distributed system are provided. A set of messages enqueued in a source queue are sent to one or more destination queues. An acknowledgement is received from each of the one or more destination queues, where the acknowledgement indicates which messages of the set of messages have been consumed at the particular destination queue. Based on the acknowledgements, one or more messages of the set messages are ceased to be maintained in the source queue.

Claims

1. A method for propagating messages in a distributed system, the method comprising:

sending, to one or more destination queues, a set of messages that are enqueued in a source queue;

receiving, from each destination queue of the one or more destination queues, an acknowledgement indicating which messages of the set of messages have been consumed at that destination queue; and

based on the acknowledgements received from each destination queue of the one or more destination queues, ceasing to maintain one or more messages of the set of messages enqueued in the source queue.

2. The method of claim 1, wherein the step of ceasing to maintain the one or more messages is performed by ceasing to maintain any message of the set of messages that has been consumed by all consumers, of the one or more destination queues, for which the set of messages was created.

3. The method of claim 1, wherein:

the set of messages comprises an ordered sequence of messages;

the acknowledgement received from each destination queue of the one or more destination queues indicates the highest numbered message in that destination queue that was consumed by all consumers of that destination queue;

the method further comprises, based on the acknowledgements received from each destination queue, determining the lowest numbered message of all the highest numbered messages in each destination queue of the one or more destination queues; and

the step of ceasing to maintain the one or more messages includes ceasing to maintain any message that is numbered lower that the lowest numbered message in the ordered sequence of messages.

4. The method of claim 1, wherein:

the one or more messages are first one or more messages; and

the method further comprises determining, based on the acknowledgements received from each destination queue of the one or more destination queues, second one or more messages of the set of messages that need to continue to be maintained in the source queue.

5. The method of claim 1, wherein the step of receiving an acknowledgement from each destination queue of the one or more destination queues further comprises storing each acknowledgement, wherein each stored acknowledgement is associated with the particular destination queue from which it was sent.

6. The method of claim 1, wherein the steps of sending the set of messages to the one or more destination queues, receiving an acknowledgement from each destination queue of the one or more destination queues, and ceasing to maintain the one or more messages in the source queue are performed by a propagation mechanism that is a consumer relative to the source queue and a publisher relative to the one or more destination queues.

7. The method of claim 1, wherein the source queue and each destination queue of the one or more destination queues are maintained at separate nodes of the distributed system.

8. The method of claim 1, wherein:

a plurality of publishers publish messages to the source queue; and

the step of sending the set of messages to the one or more destination queues comprises sending only those messages that have been enqueued in the source queue by a particular publisher of the plurality of publishers.

9. The method of claim 1, wherein the distributed system is a database management system (DBMS).

10. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 1.

11. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 2.

12. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 3.

13. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 4.

14. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 5.

15. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 6.

16. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 7.

17. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 8.

18. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 9.