Method and system for automated session resource clean-up in a distributed client-server environment

• US 20020112054A1
• Filed: 02/12/2001
• Published: 08/15/2002
• Est. Priority Date: 02/12/2001
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Hatanaka, Iwao
• Granted Patent: US 7,493,391 B2
• Time in Patent Office: Days
• US Class Current: 709/225
• CPC Class Codes: H04L 67/14 Session management for real-time applications in data packet communications networks H04L65/1066
• CPC Class Codes: H04L 67/535 Tracking the activity of the user network monitoring arrangements H04L43/00; recording of computer activity G06F11/34
• CPC Class Codes: H04L 69/28 Timers or timing mechanisms used in protocols
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

A system and method of automatic session resource clean-up resulting from a client-server session wherein the client has requested use of server resources during the session. During each session, a list of the resources allocated to that session and associated with the client is maintained and, when the session terminates, either naturally or unnaturally, the allocated resources are released or freed up, allowing later use of the same resources by a different session, either with the same client or with a different client. A session may terminate naturally because a program which is using the resource (such as a database) has completed its operation and ended normally. A session may also terminate unnaturally, e.g., because the connection between the client and the server has been broken for some reason or because a program has aborted or become hung in an inoperative state. Because such unnatural terminations do not normally provide a farewell message from the client to the server—only silence, from the lack of further processing messages—there is no way for the server to release the resource and no naturally occurring message to the server that the client is not present. The resent invention overcomes these disadvantages by determining when a session has ended and releasing the resources associated with the client.

Claims

1. A system for managing the use of resources in a system where a remote client uses resources at a server for a limited duration, the system comprising:

a stored listing of at least one resource being used at the server and the client using that resource;

a system which identifies that a remote client is no longer using resources at the server; and

in response to the system identifying that the client is no longer using resources at the server, a mechanism which removes the resources which had been used by the client when the client was connected to the server, whereby the resources being used by a client may be used by other clients after the client has disconnected from the server.

2. A system for managing the use of resources in a system including the elements of claim 1 wherein the system which identifies that a remote client is no longer using a resource at the server includes a mechanism for determining that the client is no longer connected to the server through a data transmission network.

3. A system for managing the use of resources in a system including the elements of claim 1 wherein the system which identifies that a remote client is no longer using a resource at the server includes a system for determining that the program which uses the resource has terminated.

4. A system for managing the use of a resource in a system including the elements of claim 1 wherein the server maintains a listing of each of the clients using a resource associated with the server and the resources which are used by the respective client.

5. A method of controlling the use of resources at a server by clients which are coupled to the server to use the resources, the steps of the method comprising:

identifying a client which is using the server and the resources of the server which are associated with the client;

detecting when the client is no longer using the resources of the server; and

in response to the detecting that the client is no longer using resources of the server, releasing the resources at the server which had been associated with the client.

6. The method of controlling the use of resources at a server by a client including the steps of claim 5 and further including the step of detecting that the client has become disconnected from the server.

7. The method of controlling the use of resources at a server by a client including the steps of claim 5 and further including the step of maintaining a list of the resources being used by each client using the server.

8. The method of controlling the use of resources at a server by a client including the steps of claim 5 wherein the method further includes maintaining a list of resources being used by a client, maintaining a record of the time when the use of the resource started and the time when the resource was last used and using the record of at least one of the times to determine whether to release the resource.

9. A method of controlling use of a resource at a server by a client, the steps of the method comprising:

when a client requests use of a resource at a server, entering the identity of the client, the resource and the time into a resources used listing;

when a client subsequently uses the resource, entering the time of last use of the resource into the resources used listing;

permitting a client to control a resource while the client is connected and using the resource; and

determining whether a client has been using a resource within a predetermined period of time and, if not, releasing the resource.

10. A stored program fixed on a medium for controlling the use of a resource comprising:

a module which stores a list of the resources which are being used by an identified client at a server;

a module which determines when the identified client is no longer using resources associated with the server; and

a module which determines the resources used by the identified client and releases those resources in response to determining that the identified client is no longer using resources associated with the server.

11. A stored program of the type described in claim 10 wherein the module for determining that the identified client is no longer using resources includes a mechanism for determining that the client is no longer connected to the server.