Distributed server for real-time collaboration

• US 6,334,141 B1
• Filed: 02/02/1999
• Issued: 12/25/2001
• Est. Priority Date: 02/02/1999
• Status: Expired due to Term

• Current Assignee: Activision Publishing Incorporated (Microsoft Corporation)
• Original Assignee: International Business Machines Corporation
• Inventors: Varma, Pradeep, Kumar, Suresh
• Primary Examiner(s): Dinh, Dung C.
• Assistant Examiner(s): SALAD, ABDULLAHI ELMI
• Application Number:
  US09/241,991
• Time in Patent Office: 1,057 Days
• Field of Search: 709/204, 709/205, 709/203, 709/243, 709/106, 709/105, 709/217, 709/219, 709/316, 709/315, 709/317
• US Class Current: 709/205
• CPC Class Codes: G06F 2209/505 Clust
• CPC Class Codes: H04L 12/1813 for computer conferences, e.g. chat rooms instant messaging H04L51/04; protocols for multimedia communication H04L65/1101; arrangements for multi-party communication H04L65/403; telephonic conference arrangements H04M3/56; television conference systems H04N7/15
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/125 by balancing the load, e.g. traffic engineering
• CPC Class Codes: H04L 67/10 in which an application is distributed across nodes in the network software deployment G06F8/60; multiprogramming arrangements G06F9/46
• CPC Class Codes: H04L 67/131 Protocols for games, networked simulations or virtual reality

Abstract

A distributed server for real-time collaboration is substituted for a centralized server to address the problem of the development of unacceptable communication and computation bottlenecks resulting from the use of a one-software-process-based centralized server running somewhere on the available network. The substitute distributed server improves scaleability of real-time collaboration by being based on multiple, independently-communicating, asynchronous, independent (i.e., no shared memory, data, variables, etc.) software processes. The processes can be distributed to multiple machines throughout the network and run simultaneously in order to avoid the centralized server'"'"'s bottlenecks. To be used, a distributed server requires a disjoint, fully covering partitioning of a work space, wherein it can handle partition hierarchies and groups comprehensively. The distributed server solution is general because of the ability of distributed servers to work with different definitions of a modification. The distributed server solution is extensible because of its simple and comprehensive treatment of inter-partition synchronization.

Claims

1. A method that improves the scaleability of real-time collaboration by providing distributed servers as a substitute for centralized servers used in real-time collaboration, each distributed server providing a functionality that is equivalent to a basic functionality provided by a centralized server, the method comprising the steps of:

building a distributed server that is applicable and specific to a real-time collaboration session and that includes two or more, independently-communicating, asynchronous, independent software processes that can be run simultaneously on one or more, heterogeneous or homogeneous, interconnected computers and/or computing elements; and

providing for each said real-time collaboration session and associated distributed server an unchanging disjoint partitioning of said collaboration session'"'"'s complete shared work space where one or more disjoint partitions together at any time cover the entire work space and are available at all times during said collaboration session, with no partition being created and/or deleted during said collaboration session, and at least one client that actively or passively participates in said collaboration session, wherein each said client that participates in said collaboration session does so for the entire duration.

2. The method according to claim 1, wherein said two or more software processes included in any said distributed server comprise for each said one or more disjoint partitions, a partition server corresponding to each said partition, and a collaboration server, wherein said partition servers are connected with said clients required by said distributed server by channels which are first in first out (FIFO) communication structures, said channels being a part of the distributed server, the distributed server including an interface by which said clients can communicate with any said partition server of said distributed server.

3. The method according to claim 1, wherein for any said distributed server with its said one or more disjoint partitions, a modification of said work space is either an ordinary modification wherein only one said partition is modified, or a compound modification, wherein one or more said partitions are modified.

4. The method according to claim 3, further comprising the step of providing said distributed server for any said collaboration session with a modification-serialization functionality that is equivalent to that which can be provided by a centralized server for said collaboration session, the modification-serialization functionality comprising for any partition of said work space, the sequence of serialized said ordinary and said compound modifications over said partition for a said client is the same as that for any other said client, there does not exist a said partition of said work space for which there exists a pair of said modifications over said partition such that both said modifications that originate from the same said client and the relative order between the two said modifications after said serialization differs from said relative order in which they originated from their common client, and for any said client and for any said serialized compound modification, the processing of said compound modification by said client succeeds the full processing by said client of every said serialized modification such that said serialized modification is over any of the identified partitions over which said compound modification takes place and said serialized modification precedes said compound modification.

5. The method recited in claim 4, wherein said compound modifications comprehensively allow any said distributed server to accept hierarchical or other, partition groups in said real-time-collaboration session, a hierarchical partition group corresponding to a hierarchical partition arrangement in said work space partitioning of said real-time collaboration session, wherein entire said hierarchical arrangement can be affected as a whole by one said modification.

6. The method recited in claim 5, wherein in any said distributed server, multiple partition groups can coexist and be in various stages of simultaneous processing at any time and, in any collaboration session, partition groups can be created, used, and abandoned as and when needed through the course of the collaboration session.

7. The method recited in claim 3, wherein in any said distributed server, inter-partition synchronization, including serialization, is based on relative positions of a said compound modification over identified partitions, wherein a collaboration server provides said relative positions for each said compound modification.

8. The method recited in claim 1, wherein said distributed servers have additional extensibility because of inter-partition synchronization.

9. The method recited in claim 2, wherein in any said distributed server, said partition servers rely on a FIFO-queue basis for serialization.

10. The method recited in claim 9, wherein in order to allow said partition servers to handle said compound modifications, said FIFO-queue-serialization basis is augmented to require a reasonable amount of fairness in picking from available said modifications, and uses relative positions of said compound modifications provided by a collaboration server in making said modifications available for picking.

11. The method recited in claim 9, wherein in any said distributed server, said partition servers can use past serialization decisions to serialize current modifications.

12. The method recited in claim 3, wherein a said ordinary modification over a said partition can be any of user-level operations and/or some translation of the same, the changed partition itself, and the difference in the partition from before it changes to after it has changed.

13. The method recited in claim 1, wherein for any distributed server, each of said software processes and client interfaces that enable clients to communicate with any partition server included in said distributed server are implemented both sequentially and concurrently.

14. The method recited in claim 2, wherein optimizations including sharing of said channels and said modifications, process sharing by said partition servers, and granularizing of said modifications are implemented in said distributed server.

15. The method recited in claim 1, wherein for any said distributed server, some or all of the said two or more software processes included in said distributed server are implemented in hardware.