FLOW REDIRECTION EMPLOYING STATE INFORMATION

• US 20100271964A1
• Filed: 04/27/2009
• Published: 10/28/2010
• Est. Priority Date: 04/27/2009
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Aitken, Paul J., Gillott, Mark, AKHTER, Aamer Saeed, Ramasamy, Arivu Mani
• Granted Patent: US 8,218,561 B2
• Time in Patent Office: Days
• US Class Current: 370/252
• CPC Class Codes: H04L 43/0817 by checking functioning
• CPC Class Codes: H04L 45/38 Flow based routing
• CPC Class Codes: H04L 67/563 Data redirection of data network streams

Abstract

In an example embodiment, there is disclosed an apparatus comprising a first interface configured to receive a packet from a client, a second interface configured to transmit the packet to a server, a third interface configured to communicate with at least one processing device, redirection module in communication with the first interface, the second interface and the third interface, and flow monitoring and state information module in communication with the first interface, the second interface, the third interface and the redirection module. Responsive to receipt of the packet on the first interface, the redirection module is operable to communicate with the flow monitoring and state information module whether state information exists for the packet, the state information comprising an address for a processing device. The redirection module is operable to route the packet to the processing device responsive to determining state information exists for the packet.

Claims

1. An apparatus, comprising:

a first interface configured to receive a packet from a client in communication with the first interface;

a second interface configured to transmit the packet to a server in communication with the second interface;

a module configured to communicate with at least one processing device;

a redirection module in communication with the first interface, the second interface and the module configured to communicate with at least one processing device; and

a flow monitoring and state information module in communication with the first interface, the second interface, the module configured to communicate with at least one processing device, and the redirection module;

wherein responsive to receipt of the packet on the first interface, the redirection module is operable to communicate with the flow monitoring and state information module to determine whether state information exists for the packet, the state information comprising an address for a processing device; and

wherein the redirection logic is operable to redirect the packet to the processing device via the module configured to communicate with at least one processing device responsive to determining state information exists for the packet.

2. The apparatus set forth in claim 1, wherein the redirection logic is operable to determine from a hash table an assigned processing device selected from the at least one processing device for the packet;

wherein the redirection logic is operable to update the flow monitoring and state information logic with the address for the assigned processing device; and

wherein the redirection logic is operable to route the packet to the processing device.

3. The apparatus set forth in claim 2, wherein the address for the assigned processing device is a Media Access Control (MAC) address.

4. The apparatus set forth in claim 2, wherein the address for the assigned processing device is an Internet Protocol (IP) address.

5. The apparatus set forth in claim 1, wherein the redirection module is operable to determine from a mask and a table of values an assigned processing device selected from the at lest one processing device for the packet;

wherein the redirection module is operable to update the flow monitoring and state information module with the address for the assigned processing device; and

wherein the redirection module is operable to route the packet to the processing device.

6. The apparatus set forth in claim 1, wherein the redirection module is operable to reassign flows responsive to detecting a new processing device;

and

wherein the redirection module continues to route existing flows based on data previously acquired from the flow monitoring and state information module.

7. The apparatus set forth in claim 6, wherein the redirection module is operable to update the flow monitoring and state information module responsive to reassigning an existing flow.

8. The apparatus set forth in claim 1, wherein the redirection module is operable to reassign flows responsive to a signal from a processing device indicating the processing device is unable to accept a new flow;

and

wherein the redirection module continues to route existing flows based on data previously acquired from the flow monitoring and state information module.

9. The apparatus set forth in claim 8, wherein the redirection module is operable to update the flow monitoring and state information module responsive to reassigning an existing flow.

10. The apparatus set forth in claim 1, wherein the redirection module is operable to reassign flows responsive to losing communication with a processing device;

and

wherein the redirection module continues to route existing flows based on data acquired from the flow monitoring and state information module.

11. The apparatus set forth in claim 1, wherein the packet comprises data representative of a flow comprising a source address, a source port, a destination address and a destination port;

and

wherein the redirection module is operable to determine whether state information exists for the packet based on the data representative of the flow.

12. A method, comprising:

receiving a packet from a client belonging to a flow addressed to a server;

determining whether state information exists for the flow, the state information comprises an address for a processing device for the flow; and

redirecting the packet to the packet processing device responsive to determining state information exists for the flow.

13. The method according to claim 12, wherein the receiving further comprises receiving a first packet belonging to the flow;

wherein responsive to determining state information does not exist for the flow for the first packet, the method further comprises;

determining an address for a processing device for the flow,

storing the address with the flow information, and

routing the first packet to the processing device;

wherein responsive to receiving a subsequent packet for the flow after determining an address for a processing device for the flow, the determining whether state information exists for the flow further comprises retrieving the previously determined address of the processing device responsive to determining state information exists for the flow, and the subsequent packet is redirected to the to the address of the processing device.

14. The method according to claim 13, wherein the address for the processing device is selected from the group consisting of a media access control (MAC) address and an internet protocol (IP) address.

15. The method according to claim 12, further comprising:

detecting a new processing device;

rebalancing flows responsive to detecting the new processing device; and

continuing to route a packet for a flow initiated prior to detecting the new traffic device based on existing state information for the flow.

16. The method according to claim 12, further comprising

detecting a new processing device;

rebalancing flows responsive to detecting the new processing device;

updating state information for the flow based on the rebalancing; and

routing a packet for a flow initiated prior to detecting the new traffic device based on the updated state information for the flow.

17. The method according to claim 12, further comprising

determining a processing device selected from a plurality of processing devices cannot accept new flows;

rebalancing flows responsive to determining the processing device selected from the plurality of processing devices cannot accept new flows;

continuing to route a packet for a flow initiated prior to detecting the new traffic device based on existing state information for the flow.

18. An apparatus, comprising:

a first interface configured to receive a packet from a client;

a second interface configured to communicate with a server and at least one processing device;

a redirection module configured to communicate with the first interface; and

a flow monitoring and state information module configured to communicate with the first interface, and the redirection module;

wherein responsive to receipt of the packet on the first interface, the redirection module is operable to communicate with the flow monitoring and state information module to determine whether state information exists for the packet, the state information comprising an address for a processing device; and

wherein the redirection module is operable to redirect the packet to the processing device responsive to determining state information exists for the packet.

19. The apparatus of claim 18, wherein the redirection module is operable to:

reassign flows responsive to detecting a new processing device; and

wherein the redirection module continues to route existing flows based on data previously acquired from the flow monitoring and state information module.

20. The apparatus of claim 18, wherein the first interface and the second interface are the same.

21. An apparatus, comprising:

a first interface configured to receive a packet from a client in communication with the first interface and is further configured to communicate with at least one processing device in communication with the first interface;

a second interface configured to communicate with a server;

redirection module in communication with the first interface and the second interface; and

flow monitoring and state information module in communication with the first interface, the second interface, and the redirection module;

wherein responsive to receipt of the packet on the first interface, the redirection module is operable to communicate with the flow monitoring and state information module to determine whether state information exists for the packet, the state information comprising an address for a processing device; and

wherein the redirection module is operable to redirect the packet to the processing device responsive to determining state information exists for the packet.

22. Logic encoded in at least one tangible media, and when executed operable to:

receive a first packet belonging to a flow;

determine that state information does not exist for the flow responsive to receiving the first packet;

determining an address for a processing device for the flow,

storing the address with the flow information, and

routing the first packet to the processing device;

receiving a second packet for the flow, the second packet being received after the first packet;

determining that state information exists for the flow responsive to receiving the second packet; and

redirecting the second packet to the packet processing device responsive to determining state information exists for the flow.