MECHANISM FOR TERMINATING RELAY OPERATIONS IN A DISTRIBUTED SWITCH WITH CASCADED CONFIGURATION

• US 20150023364A1
• Filed: 07/18/2013
• Published: 01/22/2015
• Est. Priority Date: 07/18/2013
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Driever, Patricia G., Hathorn, Roger G., May, Henry J., Raisch, Christoph, Sentler, Daniel
• Granted Patent: US 9,641,455 B2
• Time in Patent Office: Days
• US Class Current: 370/410
• CPC Class Codes: H04L 49/15 Interconnection of switching modules
• CPC Class Codes: H04L 49/357 Fibre channel switches
• CPC Class Codes: H04L 49/557 Error correction, e.g. fault recovery or fault tolerance

Abstract

Provided are a method, a system, and a computer program product in which a plurality of switches are maintained in a cascaded configuration. A switch relays a switch fabric internal link services (SW-ILS) to generate a pair of exchanges comprising a first exchange and a second exchange at the switch. In response to a termination of the first exchange of the pair of exchanges, the second exchange of the pair of exchanges is terminated.

Claims

1. A method, comprising:

maintaining a plurality of switches in a cascaded configuration;

relaying, by a switch, a switch fabric internal link services (SW-ILS) to generate a pair of exchanges comprising a first exchange and a second exchange at the switch; and

in response to a termination of the first exchange of the pair of exchanges, terminating the second exchange of the pair of exchanges.

2. The method of claim 1, the method further comprising:

in response to a termination of the second exchange of the pair of exchanges, terminating the first exchange of the pair of exchanges.

3. The method of claim 2, wherein the first exchange or the second exchange is terminated by either receiving or sending an abort sequence (ABTS), and wherein the plurality of switches includes a distributed Fibre Channel over Ethernet switch or a distributed Fibre Channel switch.

4. The method of claim 3, wherein terminating an exchange releases a pool of virtual resources corresponding to the exchange, in Fibre Channel over Ethernet or Fibre Channel.

5. The method of claim 1, wherein the cascaded configuration comprises an originating switch, one or more intermediate switches, and a destination switch, and wherein abort sequences are propagated both forward and backward in response to an error detected by at least one of the one or more intermediate switches.

6. The method of claim 1, wherein error detection is propagated in the cascaded configuration.

7. The method of claim 1, wherein all resources associated with an exchange relay are reclaimed in a timely manner.

8. A system, comprising:

a plurality of switches maintained in a cascaded configuration;

a memory coupled to at least one of the plurality of switches; and

a processor coupled to the memory, wherein the processor performs operations, the operations comprising;

relaying, by a switch, a switch fabric internal link services (SW-ILS) to generate a pair of exchanges comprising a first exchange and a second exchange at the switch; and

in response to a termination of the first exchange of the pair of exchanges, terminating the second exchange of the pair of exchanges.

9. The system of claim 8, the operations further comprising:

in response to a termination of the second exchange of the pair of exchanges, terminating the first exchange of the pair of exchanges.

10. The system of claim 9, wherein the first exchange or the second exchange is terminated by either receiving or sending an abort sequence (ABTS), and wherein the plurality of switches includes a distributed Fibre Channel over Ethernet switch or a distributed Fibre Channel switch.

11. The system of claim 10, wherein terminating an exchange releases a pool of virtual resources corresponding to the exchange, in Fibre Channel over Ethernet or Fibre Channel.

12. The system of claim 8, wherein the cascaded configuration comprises an originating switch, one or more intermediate switches, and a destination switch, and wherein abort sequences are propagated both forward and backward in response to an error detected by at least one of the one or more intermediate switches.

13. The system of claim 8, wherein error detection is propagated in the cascaded configuration.

14. The system of claim 8, wherein all resources associated with an exchange relay are reclaimed in a timely manner.

15. A computer program product, the computer program product comprising:

a computer readable storage medium having computer readable program code embodied therewith, the computer readable program code configured to perform operations on a processor, the operations comprising;

maintaining a plurality of switches in a cascaded configuration;

relaying, by a switch, a switch fabric internal link services (SW-ILS) to generate a pair of exchanges comprising a first exchange and a second exchange at the switch; and

in response to a termination of the first exchange of the pair of exchanges, terminating the second exchange of the pair of exchanges.

16. The computer program product of claim 15, the operations further comprising:

in response to a termination of the second exchange of the pair of exchanges, terminating the first exchange of the pair of exchanges.

17. The computer program product of claim 16, wherein the first exchange or the second exchange is terminated by either receiving or sending an abort sequence (ABTS), and wherein the plurality of switches includes a distributed Fibre Channel over Ethernet switch or a distributed Fibre Channel switch.

18. The computer program product of claim 17, wherein terminating an exchange releases a pool of virtual resources corresponding to the exchange, in Fibre Channel over Ethernet or Fibre Channel.

19. The computer program product of claim 15, wherein the cascaded configuration comprises an originating switch, one or more intermediate switches, and a destination switch, and wherein abort sequences are propagated both forward and backward in response to an error detected by at least one of the one or more intermediate switches.

20. The computer program product of claim 15, wherein error detection is propagated in the cascaded configuration.