Protocol Negotiation for a Group Communication System

• US 20080253391A1
• Filed: 04/10/2007
• Published: 10/16/2008
• Est. Priority Date: 04/10/2007
• Status: Active Grant

• Current Assignee: Twitter Inc (X Holdings Corp.)
• Original Assignee: International Business Machines Corporation
• Inventors: Vitenberg, Roman, Wecker, Alan J., Stopyro, James W., Krits, Alexander
• Granted Patent: US 7,701,970 B2
• Time in Patent Office: Days
• US Class Current: 370/466
• CPC Class Codes: H04L 12/1818 Conference organisation arrangements, e.g. handling schedules, setting up parameters needed by nodes to attend a conference, booking network resources, notifying involved parties
• CPC Class Codes: H04L 69/24 Negotiation of communication capabilities

Abstract

Methods and systems are provided in a group communication system for dynamically changing a version of a group communication protocol from a first version to a second version transparently to external sources and destinations. The system accommodates newly joining members that can only support versions of the protocol other than the version currently in use without interruption in service. Similarly, the system can upgrade its operating version of the group communication protocol to improve performance when a member having relatively low capabilities exits the group.

Claims

1. A computer-implemented method for changing a communications protocol in a group communication system having a plurality of communication entities, comprising the steps of:

defining a first view, wherein said first view specifies a first set of said communication entities and a first version of a protocol used for communication in said group communication system;

detecting a requirement to change to a second version of said protocol; and

responsively to said step of detecting, instantiating a second view, wherein said second view specifies a second set of said communication entities and said second version of said protocol.

2. The method according to claim 1, wherein instantiating a second view comprises the steps of:

disconnecting one of said communication entities from said first set of said communication entities;

forming a new view consisting only of said one communication entity;

in said new view configuring said one communication entity with said second version of said protocol; and

thereafter reconnecting said one communication entity with said second set of said communication entities.

3. The method according to claim 2, further comprising the step of determining that said first version and said second version are concurrently inoperative by said communication entities, and wherein said steps of disconnecting and reconnecting are only performed responsively to said step of determining.

4. The method according to claim 1, further comprising receiving first messages in said communication entities that are transmitted according to said first version while receiving second messages therein that are transmitted according to said second version and concurrently receiving and transmitting application message traffic in said communication entities.

5. The method according to claim 4, wherein said step of detecting a requirement comprises receiving a new message, and wherein said new message comprises an identifier of said second version of said protocol.

6. The method according to claim 5, wherein one of said communication entities in said first set is designated as a view leader, and wherein said view leader multicasts said identifier of said second version of said protocol to other said communication entities.

7. The method according to claim 1, wherein said protocol is a multicast protocol.

8. The method according to claim 1, wherein said first set comprises at least three of said communication entities.

9. A computer software product for operating a group communication system having a plurality of communication entities, including a tangible computer-readable medium in which computer program instructions are stored, which instructions, when read by a computer, cause the computer to:

define a first view, wherein said first view specifies a first set of said communication entities and a first version of a protocol used for communication in said group communication system;

detect a requirement to change to a second version of said protocol; and

responsively to a detection of said requirement to change, instantiate a second view, wherein said second view specifies a second set of said communication entities and said second version of said protocol.

10. The computer software product according to claim 9, wherein said computer is further instructed to instantiate said second view by disconnecting one of said communication entities from said first set of said communication entities, forming a new view consisting only of said one communication entity, in said new view configuring said one communication entity with said second version of said protocol, and thereafter reconnecting said one communication entity with said second set of said communication entities.

11. The computer software product according to claim 10, wherein said computer is further instructed to make a determination that said first version and said second version of said protocol are concurrently inoperative by said communication entities, and wherein said disconnecting and reconnecting are only performed responsively to said determination.

12. The computer software product according to claim 9, wherein said communication entities receive first messages that are transmitted according to said first version while receiving second messages that are transmitted according to said second version and said communication entities concurrently receive and transmit application message traffic.

13. The computer software product according to claim 9, wherein detecting said requirement comprises receiving a new message, and wherein said new message comprises an identifier of said second version of said protocol.

14. The computer software product according to claim 9, wherein said protocol is a multicast protocol.

15. A group communication system comprising a plurality of computing devices, each of said computing devices comprising:

a communication interface for communicating with other said computing devices; and

a processor, which is configured to send and receive group communication messages using a first version of a protocol via said communication interface and which is operative to change among different versions of said protocol by defining a first view of said computing devices, wherein said first view specifies a first set of said computing devices and said first version of said protocol, detecting a requirement to change to a second version of said protocol and responsively to said detection, instantiating a second view of said computing devices, wherein said second view specifies a second set of said computing devices and said second version of said protocol, and wherein said second version of said protocol is used for communication between said second set of said computing devices.

16. The group communication system according to claim 15, wherein instantiating said second view comprises disconnecting one of said computing devices from said first view to form a new view which includes only said one computing device, configuring said one computing device with said second version of said protocol in said new view and thereafter reconnecting said one computing device with said second set of said computing devices.

17. The group communication system according to claim 16, wherein said processor is further configured to make a determination that said first version and said second version of said protocol are concurrently inoperative by said computing devices, and wherein said processor is configured to disconnect from said first set of said computing devices and to reconnect to said second set of said computing devices only responsively to said determination.

18. The group communication system according to claim 15, wherein said computing devices receive first messages that are transmitted according to said first version while receiving second messages that are transmitted according to said second version.

19. The group communication system according to claim 18, wherein detecting said requirement comprises receiving a new message, and wherein said new message comprises an identifier of said second version of said protocol.

20. The group communication system according to claim 15, wherein said protocol is a multicast protocol.