Method and apparatus for coupling clients to servers

• US 6,243,751 B1
• Filed: 06/11/1997
• Issued: 06/05/2001
• Est. Priority Date: 06/11/1997
• Status: Expired due to Term

• Current Assignee: Oracle International Corporation (Oracle Corporation)
• Original Assignee: Oracle Corporation
• Inventors: Bellemore, John, Jasuja, Amit, Chatterjee, Debashish
• Primary Examiner(s): Harrell, Robert B.
• Assistant Examiner(s): WILLETT, STEPHAN F
• Application Number:
  US08/872,529
• Time in Patent Office: 1,455 Days
• Field of Search: 395/200.56, 709/226, 709/227, 709/228, 709/229
• US Class Current: 709/226
• CPC Class Codes: H04L 2101/663 Transport layer addresses, e.g. aspects of transmission control protocol [TCP] or user datagram protocol [UDP] ports
• CPC Class Codes: H04L 67/14 Session management for real-time applications in data packet communications networks H04L65/1066
• CPC Class Codes: H04L 69/32 Architecture of open systems interconnection [OSI] 7-layer type protocol stacks, e.g. the interfaces between the data link level and the physical level

Abstract

A method and apparatus allows clients to share ports on a server. The server can maintain more sessions than server ports. When a client sends a command directed to the server, a resource manager inserted between the clients and the server intercepts the command and directs the server to select the session associated with a client prior to or at the same time that the resource manager forwards the intercepted command to the server. Responses from the server are forwarded by the resource manager to the client that sent the command to which the response relates. The resource manager may be coupled to multiple clients, and one or more ports of one or more servers.

Claims

1. An apparatus for coupling a first number of clients to a second number of ports smaller than the first number of ports on at least one server, the apparatus comprising:

a set of a plurality of addressable client ports, each capable of communicating with at least one of the clients;

at least one server port, each capable of communicating with at least one of the ports of the at least one server; and

a resource manager session maintainer module coupled to at least one of the addressable client ports and at least one of the server ports for preparing and transmitting to at least one of the server ports a command to instruct the server to;

associate a first user with at least one of the at least one of the server ports associated with a second user prior to said association with the first user;

disassociate the second user from the at least one port associated with the first user; and

preserve at least a portion of status data for the second user, said status data comprising data capable of being used by the server to access data accessible by the second user, responsive to a subsequent server command from the second user.

2. The apparatus of claim 1, additionally comprising a resource manager command forwarder module coupled to at least one of the client ports in the set, the resource manager session maintainer module for receiving a command from a client port and signaling the resource manager session maintainer module that a command was received.

3. The apparatus of claim 2 wherein:

the resource manager command forwarder module is;

coupled to at least one of the at least one server ports; and

for forwarding at least a portion of the command received to at least one of the server ports; and

the resource manager session maintainer module is for directing the resource manager command forwarder module to forward to at least one of the server ports at least a portion of the command received.

4. The apparatus of claim 3 wherein the resource manager command forwarder module is additionally for modifying the command received.

5. The apparatus of claim 2 wherein:

the resource manager command forwarder module is for forwarding the command received to the resource manager session maintainer module; and

the resource manager session maintainer module is additionally for forwarding at least a portion of the command to the server port.

6. The apparatus of claim 5 wherein the resource manager session maintainer module is additionally for modifying the command received.

7. The apparatus of claim 1 wherein the resource manager session maintainer module is additionally for generating at least one handle corresponding to a client port, associating the handle generated with at least one client port and transmitting said handle to a server port.

8. The apparatus of claim 7 additionally comprising a resource manager session handle storage coupled to the resource manager session maintainer module for storing a handle corresponding to the handle generated.

9. The apparatus of claim 1 wherein the resource manager session maintainer module is for receiving a session handle from at least one server port and associating the handle received with at least one client port.

10. The apparatus of claim 9 additionally comprising a resource manager session handle storage coupled to the resource manager session maintainer module for storing a handle corresponding to the handle received.

11. The apparatus of claim 1 additionally comprising a port identifier module coupled to the resource manager session maintainer module for receiving an identifier corresponding to at least one of the client ports and for providing an identifier associated with the identifier received and corresponding to at least one of the server ports.

12. The apparatus of claim 11 wherein:

the port identifier module is additionally for identifying whether the client port identifier module received corresponds to an active port; and

the server port the port identifier module identifies corresponds to a server port over which a command corresponding to a most recent command received via the client port was sent.

13. The apparatus of claim 11 wherein the port identifier module is additionally for identifying a most recently used of the server ports and providing an identifier corresponding to said server port.

14. The apparatus of claim 11 wherein the port identifier module is additionally for identifying a least recently used of the server ports and providing an identifier corresponding to said server port.

15. A method of forwarding to a server commands from a first client and a second client, the method comprising:

receiving a command from the first client;

transmitting to the server over a port a command corresponding to the command received from the first client;

receiving a command from a second client;

directing the server to;

maintain the status of the first client, said status comprising data capable of being used by the server to access data accessible by the first client, responsive to a subsequent server command from the first client; and

associate with the second client at least one command received from the port and

transmitting to the server over the port a command corresponding to the command received from the second client.

16. The method of claim 15 comprising the additional steps of:

identifying whether the second client has an active session on the server; and

wherein the directing and transmitting steps are responsive to the second client not having an active session on the server.

17. The method of claim 15 wherein the directing step comprises transmitting at least one command to the server over the port.

18. The method of claim 15 comprising the additional step of designating the second client as having an active session on the server.

19. The method of claim 15 comprising the additional step of designating the first client as not having an active session on the server.

20. The method of claim 15 comprising the additional step of associating the port with the second client.

21. The method of claim 15 comprising the additional step of identifying whether a previous command corresponding to a command received from the second client was transmitted to the server over the port.

22. The method of claim 15 comprising the additional step of associating the second client with the server.

23. The method of claim 22 comprising the additional step of identifying whether a previous command corresponding to a command received from the second client was transmitted to the server.

24. A computer program product comprising a computer useable medium having computer readable program code embodied therein for forwarding to a server commands from a first client and a second client, the computer program product comprising:

computer readable program code devices configured to cause a computer to receive a command from the first client;

computer readable program code devices configured to cause a computer to transmit to the server over a port a command corresponding to the command received from the first client;

computer readable program code devices configured to cause a computer to receive a command from a second client;

computer readable program code devices configured to cause a computer to direct the server to;

maintain the status of the first client, said status data comprising data capable of being used by the server to access data accessible by the first client responsive to a subsequent server command from the first client; and

associate with the second client at least one command received from the port; and

computer readable program code devices configured to cause a computer to transmit to the server over the port a command corresponding to the command received from the second client.

25. The computer program product of claim 24 additionally comprising:

computer readable program code devices configured to cause a computer to identify the existence of an active session on the server with the second client; and

wherein;

the computer readable program code devices configured to cause a computer to direct the server to maintain the status of the first client and associate commands received from the port with the second client comprise computer readable program code devices configured to cause a computer to direct the server to maintain the status of the first client and associate commands received from the port with the second client responsive to the second client not having an active session on the server; and

the computer readable program code devices configured to cause a computer to transmit to the server over the port a command corresponding to the command received from the second client comprise computer readable program code devices configured to cause a computer to transmit to the server over the port a command corresponding to the command received from the second client responsive to the second client not having an active session on the server.

26. The computer program product of claim 24 wherein the computer readable program code devices configured to cause a computer to direct the server to maintain the status of the first client and associate commands received from the port with the second client comprise computer readable program code devices configured to cause a computer to transmit at least one command to the server over the port.

27. The computer program product of claim 24 additionally comprising computer readable program code devices configured to cause a computer to designate the second client as having an active session on the server.

28. The computer program product of claim 24 additionally comprising computer readable program code devices configured to cause a computer to designate the first client as not having an active session on the server.

29. The computer program product of claim 24 additionally comprising computer readable program code devices configured to cause a computer to associate the port with the second client.

30. The computer program product of claim 24 additionally comprising computer readable program code devices configured to cause a computer to identify whether a previous command corresponding to a command received from the second client was transmitted to the server over the port.

31. The computer program product of claim 24 additionally comprising computer readable program code devices configured to cause a computer to associate the second client with the server.

32. The computer program product of claim 31 additionally comprising computer readable program code devices configured to cause a computer to identify whether a previous command corresponding to a command received from the second client was transmitted to the server.

33. An apparatus for coupling a first number of clients to a second number of ports smaller than the first number of ports on at least one server, the apparatus comprising:

a set of a plurality of addressable client ports, each capable of communicating with at least one of the clients;

at least one server port, each capable of communicating with at least one of the ports of the at least one server; and

a resource manager session maintainer module coupled to at least one of the addressable client ports and at least one of the server ports for preparing and transmitting to at least one of the server ports a command to instruct the server to;

associate a first user with at least one of the at least one of the server ports associated with a second user prior to said association with the first user;

disassociate the second user from the at least one port associated with the first user; and

preserve at least a portion of status data for the second user, said status data comprising data capable of being used by the server to identify data accessible by the second user, responsive to a subsequent server command from the second user.

34. A method of forwarding to a server commands from a first client and a second client, the method comprising:

receiving a command from the first client;

transmitting to the server over a port a command corresponding to the command received from the first client;

receiving a command from a second client;

directing the server to;

maintain the status of the first client, said status comprising data capable of being used by the server to identify data accessible by the first client, responsive to a subsequent server command from the first client; and

associate with the second client at least one command received from the port and

transmitting to the server over the port a command corresponding to the command received from the second client.