Flush support for virtual synchrony

• US 20080298364A1
• Filed: 05/29/2007
• Published: 12/04/2008
• Est. Priority Date: 05/29/2007
• Status: Active Grant

• Current Assignee: Red Hat, Inc. (International Business Machines Corporation)
• Original Assignee: Red Hat, Inc. (International Business Machines Corporation)
• Inventors: Ban, Bela, Blagojevic, Vladimir
• Granted Patent: US 7,782,801 B2
• Time in Patent Office: Days
• US Class Current: 370/390
• CPC Class Codes: H04L 12/1863 comprising mechanisms for improved reliability, e.g. status reports arrangements for detecting or preventing errors by carrying supervisory signal the return channel H04L1/16
• CPC Class Codes: H04L 12/1881 with schedule organisation, e.g. priority, sequence management

Abstract

A method and apparatus for processing message is described. In one embodiment, an application programming interface is configured for receiving and sending messages. The application programming interface provides for a flush protocol to force members of a group to send all of their pending messages prior to a predetermined event, and to perform a message exchange phase as part of the flush protocol to allow all members of the group to see a same set of messages in a same view prior to installing a new view.

Claims

1. A computer-implemented method for flushing messages, the method comprising:

configuring a flush protocol to force members of a group to send all of their pending messages prior to a predetermined event; and

performing a message exchange phase as part of the flush protocol to allow all members of the group to see a same set of messages in a same view prior to installing a new view.

2. The computer-implemented method of claim 1 wherein all members of the group are to stop sending new messages until a join or state transfer is performed.

3. The computer-implemented method of claim 1 wherein performing the message exchange phase further comprises:

attaching the message exchange phase to the flush protocol.

4. The computer-implemented method of claim 1 further comprising:

multicasting all messages received from other members before multicasting the flush protocol.

5. The computer-implemented method of claim 1 further comprising:

exchanging digests with highest sequence numbers seen for all members of the group; and

multicasting only the missing messages.

6. The computer-implemented method of claim 1 wherein a channel is associated with the group.

7. The computer-implemented method of claim 1 wherein the new view is installed when a new client connects to the channel, and the new client tries to find existing channels with the same name, and joins them.

8. The computer-implemented method of claim 1 wherein messages are sent and received through a programming interface layered on top of a building block, the building block layered on top of a corresponding channel of a channel layer, the channel layer layered on top of a protocol stack, and the protocol stack coupled to a network.

9. An article of manufacture comprising:

a machine-accessible storage medium including data that, when accessed by a machine, cause the machine to perform a method comprising;

configuring a flush protocol to force members of a group to send all of their pending messages prior to a predetermined event; and

performing a message exchange phase as part of the flush protocol to allow all members of the group to see a same set of messages in a same view prior to installing a new view.

10. The article of manufacture of claim 9 wherein all members of the group are to stop sending new messages until a join or state transfer is performed.

11. The article of manufacture of claim 9 wherein performing the message exchange phase further comprises:

attaching the message exchange phase to the flush protocol.

12. The article of manufacture of claim 9 further comprising:

multicasting all messages received from other members before multicasting the flush protocol.

13. The article of manufacture of claim 9 further comprising:

exchanging digests with highest sequence numbers seen for all members of the group; and

multicasting only the missing messages.

14. The article of manufacture of claim 9 wherein a channel is associated with the group.

15. The article of manufacture of claim 9 wherein the new view is installed when a new client connects to the channel, and the new client tries to find existing channels with the same name, and joins them.

16. The article of manufacture of claim 9 wherein messages are sent and received through a programming interface layered on top of a building block, the building block layered on top of a corresponding channel of a channel layer, the channel layer layered on top of a protocol stack, and the protocol stack coupled to a network.

17. An apparatus for flushing messages comprising:

an application programming interface for receiving and sending messages;

a building block layer coupled to the application programming interface;

a channel layer coupled to the building block layer; and

a transport protocol stack coupled to the channel layer for implementing properties specified by the channel layer,

wherein the application programming interface provides for a flush protocol to force members of a group to send all of their pending messages prior to a predetermined event, and to perform a message exchange phase as part of the flush protocol to allow all members of the group to see a same set of messages in a same view prior to installing a new view.

18. The apparatus of claim 17 wherein all members of the group are to stop sending new messages until a join or state transfer is performed.

19. The apparatus of claim 17 wherein the message exchange phase is attached to the flush protocol.

20. The apparatus of claim 17 wherein the flush protocol is to multicast all messages received from other members before multicasting the flush protocol.

21. The apparatus of claim 17 wherein the flush protocol is to exchange digests with highest sequence numbers seen for all members of the group, and to multicast only the missing messages.

22. The apparatus of claim 17 wherein a channel is associated with the group.

23. The apparatus of claim 17 wherein the flush protocol is to install a new view when a new client connects to the channel, the new client tries to find existing channels with the same name, and joins them.