Flexible procedure for quiescing multiplexed client

• US 8,005,984 B2
• Filed: 10/09/2008
• Issued: 08/23/2011
• Est. Priority Date: 10/09/2008
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Rangaswamy, Shilpashree H., Campbell, Mark J., Clarke, Paul G., Horan, Michael
• Primary Examiner(s): Shaw; Peling A
• Application Number:
  US12/248,078
• Publication Number:
  US 20100095022A1
• Time in Patent Office: 1,048 Days
• Field of Search: 719/310, 719/312, 718/1, 709/208, 709/218, 709223-224, 709/230, 709237-238, 709/229
• US Class Current: 709/238
• CPC Class Codes: G06F 2209/541 Client-server
• CPC Class Codes: G06F 9/54 Interprogram communication
• CPC Class Codes: H04L 47/19 at layers above the network layer network arrangements for networked applications for scheduling or organising the servicing of application requests H04L67/60
• CPC Class Codes: H04L 67/14 Session management for real-time applications in data packet communications networks H04L65/1066
• CPC Class Codes: H04L 69/24 Negotiation of communication capabilities
• 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, system and article of manufacture are disclosed for quiescing multiplexed client messaging conversations. The invention uses plural independent mutexes to stop the application sends from both ends of a client/server channel, while allowing unsolicited control flows from the server to client to also be handled and quiesced. Once the channel is quiesced a channel-wide renegotiation, such as SSL secret key reset, can flow. The channel can then restart, again with the possibility of unsolicited server to client flows. The preferred embodiment of the invention provides a number of important advantages. For example, this embodiment allows channel-wide negotiation flows to occur on a multiplexed channel without the need to wait for application conversations to complete. It also allows channel-wide negotiation flows to occur on a multiplexed channel on which unsolicited server to client flows can occur.

Claims

1. A method of quiescing multiplexed client messaging conversations between at least one application on a client computer and a server computer, said conversations occurring over a communications channel having a server end and a client end, the method comprising the steps of:

using a plurality of independent mutexes to stop application sends from both ends of the channel, including setting a client side mutex to stop sends over the channel from the application to the server end of the channel, and setting a server side mutex to stop sends over the channel from the server end of the channel to the application;

after setting the client side mutex and the server side mutex, allowing unsolicited control flows from the server computer over the channel to the client computer to be handled and completed to end said control flows over the channel and to quiesce the channel; and

once the channel is quiesced, renegotiating a channel-wide event by conducting negotiation flows on the channel.

2. A method according to claim 1, wherein one or more application threads are used to send data to the channel from said at least one application, and wherein the using step includes the step of setting a client application thread send mutex to prevent the application threads from sending data to the channel.

3. A method according to claim 2, wherein the client includes a receive thread for receiving data sent to the client over the channel, and wherein the client application thread send mutex, when set, allows said receive thread to receive data.

4. A method according to claim 1, wherein a receive thread on the client is used to receive and to send data over the channel, and one or more application threads are used to send data to the channel from said at least one application, and wherein the using step includes the step of setting a client receive thread send mutex to prevent the receive thread from sending data over the channel.

5. A method according to claim 4, wherein one or more application threads are used to send data to the channel from said at least one application, and wherein the client receive thread send mutex, when set, allows said application threads to send data over the channel.

6. A method according to claim 5, wherein the using step includes the step of:

the client clearing the receive thread send mutex; and

the renegotiating step includes the steps of;

when the renegotiation is complete, sending a message to the application thread indicating that said renegotiation is complete; and

said application thread, in response to receiving said message, resetting the client receive thread send mutex, sending data to the server end of the channel, and then clearing the client receive thread send mutex.

7. A method according to claim 1, wherein the server computer includes a receive thread for receiving and sending data over the channel, and wherein the using step includes the step of setting a server send mutex to prevent the receive thread from sending data over the channel.

8. A method according to claim 1, wherein an application thread is used to send data to the channel from said at least one application, and wherein the using step includes the steps of:

setting a client application thread send mutex to prevent the application threads on the client from sending data to the server; and

sending a pause data sends control flow from the application thread to the server end of the channel to indicate that the channel is quiescing.

9. A method according to claim 8 wherein the using step includes the further step of, after the sending step, the application thread clearing the client receive thread send mutex.

10. A method according to claim 9, wherein a server side receive thread is located on the server end of the channel for receiving and sending data over the channel, and wherein, when the server side receive thread receives the pause data sends control flow, setting a server send mutex to stop all sever-initiated sends on the channel.

11. A system for quiescing multiplexed client messaging conversations between at least one application on a client computer and a server computer, said conversations occurring over a communications channel having a server end and a client end, the system comprising at least one processor unit configured for:

using a plurality of independent mutexes to stop application sends from both ends of the channel including setting a client side mutex to stop sends over the channel from the application to the server end of the channel, and setting a server mutex to stop sends over the channel from the server end of the channel at the application;

after setting the client side mutex and the server side mutex, allowing unsolicited control flows from the server computer over the channel to the client computer to be handled and completed to end said control flows over the channel and to quiesce the channel; and

once the channel is quiesced, renegotiating a channel-wide event by conducting negotiation flows on the channel.

12. A system according to claim 11, wherein one or more application threads are used to send data to the channel from said at least one application, and wherein the at least one processor unit is configured for setting a client application thread send mutex to prevent the application threads from sending data to the channel.

13. A system according to claim 12, wherein the client includes a receive thread for receiving data sent to the client over the channel, and wherein the client application thread send mutex, when set, allows said receive thread to receive data.

14. A system according to claim 11, wherein a receive thread on the client is used to receive and to send data over the channel, and one or more application threads are used to send data to the channel from said at least one application, and wherein the processor unit is configured for setting a client receive thread send mutex to prevent the receive thread from sending data over the channel.

15. A system according to claim 14, wherein one or more application threads are used to send data to the channel from said at least one application, and wherein the client receive thread send mutex, when set, allows said application threads to send data over the channel.

16. An article of manufacture comprising

at least one computer usable medium having computer readable program code logic to execute a machine instruction in a processing unit for quiescing multiplexed client messaging conversations between at least one application on a client computer and a server computer, said conversations occurring over a communications channel having a server end and a client end, the computer readable program code logic, when executing, performing the following steps:

using a plurality of independent mutexes to stop application sends from both ends of the channel, including setting a client side mutex to stop sends over the channel from the application to the server end of the channel, and setting a server side mutex to stop sends over the channel from the server end of the channel to the application;

after setting the client side mutex and the server side mutex, allowing unsolicited control flows from the server computer to the client computer over the channel to be handled and completed to end said control flows over the channel and to quiesce the channel; and

once the channel is quiesced, renegotiating a channel-wide event by conducting negotiation flows on the channel.

17. An article of manufacture according to claim 16, wherein the server computer includes a receive thread for receiving and sending data over the channel, and wherein the using step includes the step of setting a server send mutex to prevent the receive thread from sending data over the channel.

18. An article of manufacture according to claim 16, wherein an application thread is used to send data to the channel from said at least one application, and wherein the using step includes the steps of:

setting a client application thread send mutex to prevent the application threads on the client from sending data to the server; and

sending a pause data sends control flow from the application thread to the server end of the channel to indicate that the channel is quiescing.

19. An article of manufacture according to claim 18 wherein the using step includes the further step of, after the sending step, the application thread clearing the client receive thread send mutex.

20. An article of manufacture according to claim 19, wherein a server side receive thread is located on the server end of the channel for receiving and sending data over the channel, and wherein, when the server side receive thread receives the pause data sends control flow, setting a server send mutex to stop all sever-initiated sends on the channel.