High availability for distributed network services in an extended bridge

1. A method comprising:

monitoring, by a controlling bridge (CB) in an extended bridge, availability of a plurality of port extenders (PEs) in the extended bridge, wherein the monitoring comprises checking for changes in status of inter-process communication (IPC) sessions established between the CB and the plurality of PEs, wherein the changes in status of the IPC sessions indicate whether the plurality of PEs are reachable by the CB;

in response to the monitoring, detecting, by the CB, a status change of a PE in the plurality of PEs;

identifying, by the CB, one or more rule contexts associated with the PE; and

for each rule context in the one or more rule contexts:

determining, by the CB for the rule context, one or more packet classification rules to be programmed on the PE; and

transmitting, by the CB, a message identifying the one or more packet classification rules to the PE.

2. The method of claim 1 wherein the status change indicates that the PE has newly joined the extended bridge.

3. The method of claim 1 wherein the status change indicates that the PE has been rebooted.

4. The method of claim 1 wherein each of the one or more rule contexts is associated with a network service or protocol running on the CB.

5. The method of claim 4 wherein determining, for the rule context, one or more packet classification rules to be programmed on the PE comprises:

invoking a callback API exposed by the network service or protocol associated with the rule context.

6. The method of claim 5 wherein the callback API is configured to perform a walk of a tuple space of packet classification rules.

7. The method of claim 1 further comprising:

synchronizing, to a standby CB, state information regarding packet classification rules that are in process of being distributed to the plurality of PEs in the extended bridge.

8. A non-transitory computer readable storage medium having stored thereon program code executable by a controlling bridge (CB) in an extended bridge, the program code causing the CB to:

monitor availability of a plurality of port extenders (PEs) in the extended bridge, wherein the monitoring comprises checking for changes in status of inter-process communication (IPC) sessions established between the CB and the plurality of PEs, and wherein the changes in status of the IPC sessions indicate whether the plurality of PEs are reachable by the CB;

in response to the monitoring, detect a status change of a PE in the plurality of PEs;

identify one or more rule contexts associated with the PE; and

for each rule context in the one or more rule contexts:

determine, for the rule context, one or more packet classification rules to be programmed on the PE; and

transmit a message identifying the one or more packet classification rules to the PE.

9. The non-transitory computer readable storage medium of claim 8 wherein the status change indicates that the PE has newly joined the extended bridge.

10. The non-transitory computer readable storage medium of claim 8 wherein the status change indicates that the PE has been rebooted.

11. The non-transitory computer readable storage medium of claim 8 wherein each of the one or more rule contexts is associated with a network service or protocol running on the CB.

12. The non-transitory computer readable storage medium of claim 11 wherein determining, for the rule context, one or more packet classification rules to be programmed on the PE comprises:

invoking a callback API exposed by the network service or protocol associated with the rule context.

13. The non-transitory computer readable storage medium of claim 12 wherein the callback API is configured to perform a walk of a tuple space of packet classification rules.

14. The non-transitory computer readable storage medium of claim 8 wherein the program code further causes the CB to:

synchronize, to a standby CB, state information regarding packet classification rules that are in process of being distributed to the plurality of PEs in the extended bridge.

15. A controlling bridge (CB) in an extended bridge, the CB comprising:

a processor; and

a non-transitory computer readable medium having stored thereon program code that, when executed by the processor, causes the processor to:

monitor availability of a plurality of port extenders (PEs) in the extended bridge, wherein the monitoring comprises checking for changes in status of inter-process communication (IPC) sessions established between the CB and the plurality of PEs, and wherein the changes in status of the IPC sessions indicate whether the plurality of PEs are reachable by the CB;

in response to the monitoring, detect a status change of a PE in the plurality of PEs;

identify one or more rule contexts associated with the PE; and

for each rule context in the one or more rule contexts:

determine, for the rule context, one or more packet classification rules to be programmed on the PE; and

transmit a message identifying the one or more packet classification rules to the PE.

16. The CB of claim 15 wherein the status change indicates that the PE has newly joined the extended bridge.

17. The CB of claim 15 wherein the status change indicates that the PE has been rebooted.

18. The CB of claim 15 wherein each of the one or more rule contexts is associated with a network service or protocol running on the CB.

19. The CB of claim 18 wherein determining, for the rule context, one or more packet classification rules to be programmed on the PE comprises:

invoking a callback API exposed by the network service or protocol associated with the rule context.

20. The CB of claim 19 wherein the callback API is configured to perform a walk of a tuple space of packet classification rules.

21. The CB of claim 15 wherein the program code further causes the processor to:

synchronize, to a standby CB, state information regarding packet classification rules that are in process of being distributed to the plurality of PEs in the extended bridge.