Server Load Balancer Traffic Steering

• US 20140207968A1
• Filed: 01/23/2013
• Published: 07/24/2014
• Est. Priority Date: 01/23/2013
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Bagepalli, Nagaraj A., Kumar, Surendra M., Chao, Wei-Chun
• Granted Patent: US 9,197,549 B2
• Time in Patent Office: Days
• US Class Current: 709/244
• CPC Class Codes: H04L 45/38 Flow based routing
• CPC Class Codes: H04L 45/64 using an overlay routing layer
• CPC Class Codes: H04L 47/125 by balancing the load, e.g. traffic engineering

Abstract

A network switch comprises a load balancer steering mechanism configured to receive a service request received from a load balancer and forward the service request to a first server in a load-balanced server cluster. The service request was initiated by a client and transmitted to the load balancer. The network switch is configured to receive return traffic transmitted by the first server, and to automatically steer the return traffic to the load balancer.

Claims

1. A method comprising:

receiving, at a network switch, a service request forwarded from a load balancer on an overlay network, wherein the service request was initiated by a client;

forwarding the service request to a first server in a load-balanced server cluster;

receiving, at the network switch, a server traffic flow transmitted by a server in the load-balanced server cluster; and

automatically steering the server traffic flow to the load balancer on the overlay network.

2. The method of claim 1, wherein automatically steering the server traffic flow to the load balancer comprises:

determining, on a per-flow basis, whether to steer the server traffic flow to the load balancer

3. The method of claim 1, wherein automatically steering the server traffic flow to the load balancer comprises:

steering all packets received on certain ports linked to the load-balanced server cluster to the load balancer.

4. The method of claim 1, wherein automatically steering the server traffic flow to the load balancer further comprises:

encapsulating packets of the server traffic flow with an overlay header.

5. The method of claim 1, wherein packets in the service request received at the network switch are encapsulated with an overlay header to include metadata, and further comprising:

decapsulating the packets in the service request;

extracting the metadata from the overlay header; and

processing the packets in the service request based on the metadata.

6. The method of claim 5, further comprising:

determining, on a per-flow basis, if forwarding of the packets in the server request is permitted.

7. The method of claim 1, wherein the load balancer is configured to determine if the server traffic flow is return traffic, and further comprising:

receiving, at the network switch, the server traffic flow back from the load balancer on the overlay network along with an offload indication signaling that the server traffic flow should be offloaded from the load balancer; and

in response to the offload indication, configuring network switch such that future server traffic associated with the server traffic flow bypasses the load balancer.

8. The method of claim 1, further comprising

determining, at the load balancer, that the server traffic flow is return traffic;

and

forwarding the server traffic flow to a client.

9. The method of claim 1, further comprising

transmitting, at the load balancer, the service request to the switch on the overlay network without performing source network address translation on packets in the service request.

10. An apparatus comprising:

a plurality of network ports;

a memory; and

a processor configured to;

receive, a service request forwarded from a load balancer on an overlay network, wherein the service request was initiated by a client;

forward the service request to a first server in a load-balanced server cluster;

receive a server traffic flow transmitted by a server in the load-balanced server cluster; and

automatically steer the server traffic flow to the load balancer on the overlay network.

11. The apparatus of claim 10, wherein to automatically steer the server traffic flow to the load balancer, the processor is configured to:

determine, on a per-flow basis, whether to steer the server traffic flow to the load balancer

12. The apparatus of claim 10, wherein to automatically steer the server traffic flow to the load balancer, the processor is configured to:

steering all packets received on certain ports linked to the load-balanced server cluster to the load balancer.

13. The apparatus of claim 10, wherein to automatically steer the server traffic flow to the load balancer, the processor is configured to:

encapsulating packets of the server traffic flow with an overlay header.

14. The apparatus of claim 10, wherein packets in the received service request are encapsulated with an overlay header to include metadata, and wherein the processor is configured to:

decapsulate the packets in the service request;

extract the metadata from the overlay header; and

process the packets in the service request based on the metadata.

15. The apparatus of claim 14, wherein the processor is configured to:

determine, on a per-flow basis, if forwarding of the packets in the server request is permitted.

16. The apparatus of claim 10, wherein the load balancer is configured to determine if the server traffic flow is return traffic, and wherein the processor is configured to:

receive the server traffic flow back from the load balancer on the overlay network along with an offload indication signaling that the server traffic flow should be offloaded from the load balancer; and

in response to the offload indication, bypassing the load balancer when future server traffic associated with the server traffic flow is received.

17. One or more computer readable storage media encoded with software comprising computer executable instructions and when the software is executed operable to:

receive, at a network switch, a service request forwarded from a load balancer on an overlay network, wherein the service request was initiated by a client;

forward the service request to a first server in a load-balanced server cluster;

receiving, at the network switch, a server traffic flow transmitted by a server in the load-balanced server cluster; and

automatically steer the server traffic flow to the load balancer on the overlay network.

18. The computer readable storage media of claim 17, wherein the instructions operable to automatically steer the server traffic flow to the load balancer comprise instructions operable to:

determine, on a per-flow basis, whether to steer the server traffic flow to the load balancer

19. The computer readable storage media of claim 17, wherein the instructions operable to automatically steer the server traffic flow to the load balancer comprise instructions operable to:

steer all packets received on certain ports linked to the load-balanced server cluster to the load balancer.

20. The computer readable storage media of claim 17, wherein the instructions operable to automatically steer the server traffic flow to the load balancer comprise instructions operable to:

encapsulate packets of the server traffic flow with an overlay header.

21. The computer readable storage media of claim 17, wherein packets in the service request received at the network switch are encapsulated with an overlay header to include metadata, and further comprising instructions operable to:

decapsulate the packets in the service request;

extract the metadata from the overlay header; and

process the packets in the service request based on the metadata.

22. The computer readable storage media of claim 21, further comprising instructions operable to:

determine, on a per-flow basis, if forwarding of the packets in the server request is permitted.

23. The computer readable storage media of claim 17, wherein the load balancer is configured to determine if the server traffic flow is return traffic, and further comprising instructions operable to:

receive, at the network switch, the server traffic flow back from the load balancer on the overlay network along with an offload indication signaling that the server traffic flow should be offloaded from the load balancer; and

in response to the offload indication, configure network switch such that future server traffic associated with the server traffic flow bypasses the load balancer.