Disjoint multi-pathing for a data center network

• US 9,185,166 B2
• Filed: 02/28/2012
• Issued: 11/10/2015
• Est. Priority Date: 02/28/2012
• Status: Active Grant

• Current Assignee: Kyndryl Incorporated
• Original Assignee: International Business Machines Corporation
• Inventors: DeCusatis, Casimer M., Kamble, Keshav G., Kumbhare, Abhijit P., Recio, Renato J., Singh, Simarbir
• Primary Examiner(s): CATTUNGAL, AJAY P
• Application Number:
  US13/407,658
• Publication Number:
  US 20130223440A1
• Time in Patent Office: 1,351 Days
• US Class Current: 1/1
• CPC Class Codes: H04L 45/021 Ensuring consistency of routing table updates, e.g. by using epoch numbers
• CPC Class Codes: H04L 45/1283 with disjoint links
• CPC Class Codes: H04L 45/24 Multipath
• CPC Class Codes: H04L 49/357 Fibre channel switches
• CPC Class Codes: H04L 67/1097 for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS]

Abstract

According to one embodiment, a data center fabric network system includes a controller, a plurality of switches connected to the controller via a plurality of communication links, a source device connected to at least a first switch of the plurality of switches, a destination device connected to at least a second switch of the plurality of switches, and wherein the controller is adapted for: creating a topology of the data center fabric network system, determining paths between the plurality of switches, calculating one or more disjoint multi-paths from the source device to the destination device based on the topology, and writing the one or more disjoint multi-paths into a forwarding table of at least one of: the source device, the first switch, and a nearest shared switch to the source device.

Claims

1. A data center fabric network system, comprising:

a switch controller;

a plurality of switches directly connected to the switch controller via a plurality of secure communication links, the plurality of switches being restricted from executing a discovery protocol to determine paths to other switches in the system;

a source device connected to at least a first switch of the plurality of switches;

a destination device connected to at least a second switch of the plurality of switches; and

wherein the switch controller is configured to;

create a topology of the data center fabric network system,

determine paths between the plurality of switches using path calculations performed by the switch controller,

calculate one or more disjoint multi-paths from the source device to the destination device based on the topology by determining whether a fully disjoint multi-path is available from the source device to the destination device, the one or more disjoint multi-paths being fully disjoint based on a determination that a fully disjoint multi-path is available from the source device to the destination device and being partially disjoint based on a determination that a fully disjoint multi-path is not available from the source device to the destination device, and

write the one or more disjoint multi-paths into a forwarding table of the source device, the source device being configured to communicate with the switch controller during the writing of the one or more disjoint multi-paths into the forwarding table, and

write the one or more disjoint multi-paths into a switch forwarding table of a nearest shared switch to the source device so that all traffic sent from the source device is routed through the nearest shared switch.

2. The system as recited in claim 1, wherein the switch controller is configured to operate as an OpenFlow controller.

3. The system as recited in claim 1, wherein the switch controller is further configured to store the determined paths between each switch and all other switches to a switch forwarding table in each switch.

4. The system as recited in claim 1, wherein the switch controller is further configured to:

calculate at least one disjoint multi-path between each switch and all other switches in the system; and

write the at least one disjoint multi-path into a switch forwarding table of each switch.

5. The system as recited in claim 4, wherein the switch controller is further configured to:

detect a change in the system;

in response to the change in the system, re-calculate at least one disjoint multi-path between each switch and all other switches in the system by determining whether a fully disjoint multi-path is available from the source device to the destination device, the at least one disjoint multi-path being fully disjoint based on a determination that a fully disjoint multi-path is available from the source device to the destination device and being partially disjoint based on a determination that a fully disjoint multi-path is not available from the source device to the destination device; and

write the at least one disjoint multi-path into the switch forwarding table of each switch,

wherein the change in the system comprises one of;

addition of a switch to the system, removal of a switch from the system, and change of a property of a switch in the system.

6. The system as recited in claim 1, wherein the switch controller is further configured to:

detect a change in the system affecting a disjoint multi-path between the source device and the destination device;

in response to the change in the system, re-calculate one or more disjoint multi-paths from the source device to the destination device by determining whether a fully disjoint multi-path is available from the source device to the destination device, the at least one disjoint multi-path being fully disjoint based on a determination that a fully disjoint multi-path is available from the source device to the destination device and being partially disjoint based on a determination that a fully disjoint multi-path is not available from the source device to the destination device; and

write the one or more re-calculated disjoint multi-paths into the forwarding table of at least one of;

the source device, the first switch, and the nearest shared switch to the source device,

wherein the change in the system comprises one of;

addition of a switch to the system, removal of a switch from the system, and change of a property of a switch in the system.

7. The system as recited in claim 1, wherein the one or more disjoint multi-paths from the source device to the destination device are calculated in response to a request from the source device or the nearest shared switch to the source device.

8. The system as recited in claim 1, wherein each of the one or more disjoint multi-paths comprise at least two paths that are disjoint from one another resulting in at least one fully redundant path, and wherein a partially disjoint multi-path comprises at least two paths that share a minimum number of devices in the system.

9. The system as recited in claim 1, wherein a control plane for each of the plurality of switches is controlled by the switch controller.

10. A computer program product, the computer program product comprising non-transitory a computer readable storage medium having computer readable program code embodied therewith, the computer readable program code comprising:

computer readable program code configured to create a topology of a data center fabric network system, wherein the system comprises a plurality of switches and a switch controller coupled directly to the plurality of switches via secure communication links, the plurality of switches being restricted from executing a discovery protocol to determine paths to other switches in the system;

computer readable program code configured to determine paths between each switch and all other switches of the system using path calculations performed by the switch controller;

computer readable program code configured to calculate one or more disjoint multi-paths from a source device to a destination device in the system using the switch controller by determining whether a fully disjoint multi-path is available from the source device to the destination device, the one or more disjoint multi-paths being fully disjoint based on a determination that a fully disjoint multi-path is available from the source device to the destination device and being partially disjoint based on a determination that a fully disjoint multi-path is not available from the source device to the destination device; and

computer readable program code configured to write, using the switch controller, the one or more disjoint multi-paths into a forwarding table of the source device, the source device being configured to communicate with the switch controller during the writing of the one or more disjoint multi-paths into the forwarding table; and

computer readable program code configured to write, using the switch controller, the one or more disjoint multi-paths into a switch forwarding table of a nearest shared switch to the source device so that all traffic sent from the source device is routed through the nearest shared switch.

11. The computer program product as recited in claim 10, further comprising computer readable program code configured to store, using a switch controller, the determined paths to a switch forwarding table in each switch of the system.

12. The computer program product as recited in claim 10, further comprising:

computer readable program code configured to calculate, using the switch controller, at least one disjoint multi-path between each switch and all other switches in the system; and

computer readable program code configured to write the at least one disjoint multi-path into a switch forwarding table of each switch.

13. The computer program product as recited in claim 12, further comprising:

computer readable program code configured to detect a change in the system using a switch controller;

computer readable program code configured to re-calculate at least one disjoint multi-path between each switch and all other switches in the system in response to the change in the system by determining whether a fully disjoint multi-path is available from the source device to the destination device, the at least one disjoint multi-path being fully disjoint based on a determination that a fully disjoint multi-path is available from the source device to the destination device and being partially disjoint based on a determination that a fully disjoint multi-path is not available from the source device to the destination device; and

computer readable program code configured to write the at least one disjoint multi-path into the switch forwarding table of each switch,

wherein the change in the system comprises one of;

addition of a switch to the system, removal of a switch from the system, and change of a property of a switch in the system.

14. The computer program product as recited in claim 10, further comprising:

computer readable program code configured to detect a change in the system using a switch controller, the change affecting a disjoint multi-path between the source device and the destination device;

computer readable program code configured to re-calculate one or more disjoint multi-paths from the source device to the destination device in response to the change in the system by determining whether a fully disjoint multi-path is available from the source device to the destination device, the one or more disjoint multi-paths being fully disjoint based on a determination that a fully disjoint multi-path is available from the source device to the destination device and being partially disjoint based on a determination that a fully disjoint multi-path is not available from the source device to the destination device; and

computer readable program code configured to write the one or more re-calculated disjoint multi-paths into the forwarding table of at least one of;

the source device and the nearest shared switch to the source device,

wherein the change in the system comprises one of;

addition of a switch to the system, removal of a switch from the system, and change of a property of a switch in the system.

15. The computer program product as recited in claim 10, wherein the one or more disjoint multi-paths from the source device to the destination device are calculated in response to a request from the source device or the nearest shared switch to the source device.

16. The computer program product as recited in claim 10, wherein each of the one or more disjoint multi-paths comprise at least two paths that are disjoint from one another resulting in at least one fully redundant path, and wherein a partially disjoint multi-path comprises at least two paths that share a minimum number of devices in the system.

17. A method for determining disjoint multi-paths in a data center fabric network system, the method comprising:

creating a topology of a data center fabric network system using a switch controller, wherein the system comprises a plurality of switches and the switch controller coupled directly to the plurality of switches via secure communication links, the plurality of switches being restricted from executing a discovery protocol to determine paths to other switches in the system;

determining paths between the plurality of switches using path calculations performed by the switch controller;

storing, using the switch controller, the determined paths to a switch forwarding table in each switch of the plurality of switches;

calculating one or more disjoint multi-paths from a source device to a destination device in the system using the switch controller, wherein each of the one or more disjoint multi-paths comprise at least two paths that are disjoint from one another to as great of an extent as possible given the topology of the data center fabric network system resulting in at least one fully redundant path between the source device and the destination device; and

writing, using the switch controller, the one or more disjoint multi-paths into at least a forwarding table of a nearest shared switch to the source device that is part of at least one disjoint multi-path, the nearest shared switch to the source device being configured to communicate with the switch controller during the writing of the one or more disjoint multi-paths into at least the forwarding table of the nearest shared switch to the source device.

18. The method as recited in claim 17, further comprising:

calculating at least one disjoint multi-path between each switch and all other switches in the system; and

writing the at least one disjoint multi-path into a switch forwarding table of each switch.

19. The method as recited in claim 18, further comprising:

detecting a change in the system affecting a disjoint multi-path between the source device and a destination device;

re-calculating at least one disjoint multi-path between each switch and all other switches in the system in response to the change in the system; and

writing the at least one disjoint multi-path into the switch forwarding table of each switch,

wherein the change in the system comprises one of;

addition of a switch to the system, removal of a switch from the system, and change of a property of a switch in the system.

20. The method as recited in claim 19, wherein the change in the system comprises change of a property of a switch in the system.

21. The method as recited in claim 19, wherein the change in the system comprises addition of a switch to the system.

22. The method as recited in claim 18, wherein the one or more disjoint multi-paths from the source device to the destination device are calculated in response to a request being received by the switch controller from the source device and/or the nearest shared switch to the source device.

23. The method as recited in claim 17, wherein the switch controller determines the paths between the plurality of switches.