ADAPTIVE SETTING OF THE QUANTIZED CONGESTION NOTIFICATION EQUILIBRIUM SETPOINT IN CONVERGED ENHANCED EITHERNET NETWORKS

• US 20140281021A1
• Filed: 03/15/2013
• Published: 09/18/2014
• Est. Priority Date: 03/15/2013
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Chrysos, Nikolaos, Crisan, Daniel, DeCusatis, Casimer M., Gusat, Mircea, Minkenberg, Cyriel J., Neeser, Fredy D.
• Granted Patent: US 9,954,781 B2
• Time in Patent Office: Days
• US Class Current: 709/235
• CPC Class Codes: H04L 47/12 Avoiding congestion; Recovering from congestion
• CPC Class Codes: H04L 47/122 by diverting traffic away from congested entities

Abstract

Embodiments relate to controlling workload flow on converged Ethernet links. An aspect includes coupling, by a processing device, a first control loop to a second control loop. The second control loop monitors the operation of the first control loop. An equilibrium set point is initialized for the second control loop prior to commencing operation of the first control loop. Accordingly, the equilibrium set point value is adjusted in the second control loop continuously based on a rate of operation of the first control loop.

Claims

1. A computer-implemented method for controlling workload flow on converged Ethernet links, comprising:

coupling, by a processing device, a first control loop to a second control loop, the second control loop monitoring the operation of the first control loop;

initializing an equilibrium set point for the second control loop prior to commencing operation of the first control loop; and

adjusting the equilibrium set point value in the second control loop continuously based on a rate of operation of the first control loop.

2. The computer-implemented method of claim 1, wherein the first control loop runs a priority flow control protocol.

3. The computer-implemented method of claim 1, wherein the second control loop runs a quantized congestion notification protocol.

4. The computer-implemented method of claim 1, wherein the initializing of the equilibrium set point value further comprises establishing a low equilibrium set point value to ensure that the second control loop will activate prior to the first control loop.

5. The computer-implemented method of claim 4, wherein the low equilibrium set point value is initialized to trigger the transmission of a congestion notification message when a queue in the network reaches a predetermined capacity.

6. The computer-implemented method of claim 1, wherein the adjusting of the equilibrium set point value in the second control loop further comprises dynamically increasing the equilibrium set point value based on the monitoring of the operation of the first control loop.

7. The computer-implemented method of claim 6, wherein, responsive to encountering a flag indicating a triggering of the first control loop, pausing the increase of the equilibrium set point value.

8. A computer system configured to control a workload flow on converged Ethernet links, the computer system comprising:

a memory having computer readable instructions; and

a processing device for executing the computer readable instructions, the instructions including;

coupling, by a processing device, a first control loop to a second control loop, the second control loop monitoring the operation of the first control loop;

initializing an equilibrium set point for the second control loop prior to commencing operation of the first control loop; and

adjusting the equilibrium set point value in the second control loop continuously based on a rate of operation of the first control loop.

9. The computer system of claim 8, wherein the first control loop runs a priority flow control protocol.

10. The computer system of claim 8, wherein the second control loop runs a quantized congestion notification protocol.

11. The computer system of claim 8, wherein the initializing of the equilibrium set point value further comprises establishing a low equilibrium set point value to ensure that the second control loop will always activate prior to the first control loop.

12. The computer system of claim 11, wherein the low equilibrium set point value is initialized to trigger the transmission of a congestion notification message according to a QCN scheme.

13. The computer system of claim 8, wherein the adjusting of the equilibrium set point value in the second control loop further comprises dynamically increasing the equilibrium set point value based on the monitoring of the operation of the first control loop.

14. The computer system of claim 13, wherein, responsive to encountering a flag indicating a triggering of the first control loop, pausing the increase of the equilibrium set point value.

15. The computer system of claim 8, wherein the processing device is a central control processor external to switches in a network, the central control processor configured to execute computer readable instructions that provide centralized control of network packet flows without requiring physical access to the hardware devices in the network.

16. A computer program product for controlling workload flow on converged Ethernet links, the computer program product comprising:

a computer readable storage medium having program code embodied therewith, the program code executable by a processing device for;

coupling, by a processing device, a first control loop to a second control loop, the second control loop monitoring the operation of the first control loop;

initializing an equilibrium set point for the second control loop prior to commencing operation of the first control loop; and

adjusting the equilibrium set point value in the second control loop continuously based on a rate of operation of the first control loop.

17. The computer program product of claim 16, wherein the first control loop runs a priority flow control protocol.

18. The computer program product of claim 16, wherein the second control loop runs a quantized congestion notification protocol.

19. The computer program product of claim 16, wherein the initializing of the equilibrium set point value further comprises establishing a low equilibrium set point value to ensure that the second control loop will activate prior to the first control loop.

20. The computer program product of claim 19, wherein the low equilibrium set point value is initialized to trigger the transmission of a congestion notification message when a queue of a switch in the network reaches a predetermined capacity.

21. The computer program product of claim 16, wherein the adjusting of the equilibrium set point value in the second control loop further comprises dynamically increasing the equilibrium set point value based on the monitoring of the operation of the first control loop.

22. The computer program product of claim 21, wherein, responsive to encountering a flag indicating a triggering of the first control loop, pausing the increase of the equilibrium set point value.