Methods for performing client-hosted application sessions in distributed processing systems

• US 20020035604A1
• Filed: 08/29/2001
• Published: 03/21/2002
• Est. Priority Date: 07/16/1997
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Cohen, Andrew R., Olson, Kipley J.
• Granted Patent: US 6,560,636 B2
• Time in Patent Office: Days
• US Class Current: 709/205
• CPC Class Codes: A63F 2300/402 Communication between platforms, i.e. physical link to protocol
• CPC Class Codes: H04L 67/00 Network arrangements or protocols for supporting network services or applications user-to-user messaging H04L51/00; network arrangements, protocols or services for supporting real-time applications in data packet communications networks H04L65/00
• 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 67/1095 Replication or mirroring of data, e.g. scheduling or transport for data synchronisation between network nodes
• CPC Class Codes: H04L 67/131 Protocols for games, networked simulations or virtual reality
• CPC Class Codes: H04L 67/14 Session management for real-time applications in data packet communications networks H04L65/1066
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

Methods of performing client-hosted application sessions in distributed processing systems. The application sessions involve network connected application clients sharing common data and state information. An application client designated as a host client selectively admits other clients into the application session and distributes a common set of application data to each newly admitted application client. The application data includes a unique identifier, assigned by the host client, for each application client in the application session. When a new client is admitted into an application session, application data is transmitted to it in a manner such that the new client receives data that is synchronized with the data possessed by the other application clients in the session. Changes in the application data made by an application client are communicated directly from the application client to other application clients so that each client can maintain a common set of application data. When the host client exits the application session, the host duties are automatically migrated to a new host client selected from among the remaining application clients.

Claims

1. In a distributed processing system including application clients that participate in an application session executed in the distributed processing system, a method of causing host duties for the application session to migrate from a first client to a second client, the method comprising the steps of:

executing the application session at the distributed processing system, wherein the application clients participate in the application session, the application clients including at least a first client that has the hosting duties for the application session, a second client, and a third client;

as part of the application session, storing at each of the application clients a data structure that includes a unique identifier associated with at least each of the other application clients;

exiting the application session by the first client, such that the remaining application clients include at least the second client and the third client;

as the application session continues, selecting the second client for the host duties based on predetermined selection criteria; and

causing the host duties to migrate to the second client.

2. A method as recited in claim 1, wherein the data structure includes unique identifiers associated with all of the application clients that participate in the application session.

3. A method as recited in claim 2, wherein the step of selecting the second client is conducted by any of the remaining application clients by performing the step of examining the unique identifiers that are included in the data structure and are associated with the remaining application clients.

4. A method as recited in claim 3, wherein:

the unique identifiers are numerical unique identifiers; and

the step of examining the unique identifiers that are associated with the remaining application clients comprises the step of applying the predetermined criteria to the unique identifiers that are associated with the remaining application clients.

5. A method as recited in claim 4, wherein the predetermined criteria relates to the relative values of the unique identifiers, the step of applying the predetermined criteria comprising the step of comparing the relative values of the unique identifiers that are associated with the remaining application clients.

6. A method as recited in claim 5, wherein the unique identifier associated with the second client has the greatest value among the unique identifiers associated with the remaining application clients.

7. A method as recited in claim 5, wherein the unique identifier associated with the second client has the least value among the unique identifiers associated with the remaining application clients.

8. A method as recited in claim 1, further comprising the step of selectively adding a new application client to the application session by the first client as part of the host duties prior to the step of exiting the application session by the first client.

9. A method as recited in claim 8, further comprising the step of selectively adding another new application client to the application session by the second client as part of the host duties after the step of causing the host duties to migrate to the second client.

10. In a client computer included in a distributed processing system, a method for assuming host duties associated with an application session executed in the distributed processing system when a first host client included in the distributed processing system exits the application session, the method comprising the steps of:

participating in the application session while the first host client has the host duties, the application session being participated in by application clients included in the distributed processing system, the application clients including at least the client computer, the first host client, and another client;

as part of the application session, storing a data structure that includes a unique identifier associated with at least each of the other application clients, wherein the other application clients include at least the first host client and said other client;

in response to the first host client exiting the application session, and as the application session continues, the client computer identifying itself, based on predetermined criteria, as a new host client that is to assume the host duties; and

assuming the host duties at the client computer in response to the client computer identifying itself.

11. A method as recited in claim 10, wherein the step of the client computer identifying itself comprises the step of the client computer applying the predetermined criteria to the unique identifiers that are included in the data structure and are associated with the remaining application clients, wherein the remaining application clients include at least the client computer and said other client.

12. A method as recited in claim 11, wherein:

the unique identifiers are numerical unique identifiers;

the predetermined criteria relates to the relative values of the unique identifiers; and

the step of applying the predetermined criteria comprises the step of comparing the relative values of the unique identifiers that are associated with the remaining application clients.