Link load balancer that controls a path for a client to connect to a resource

• US 8,516,129 B1
• Filed: 04/11/2011
• Issued: 08/20/2013
• Est. Priority Date: 08/05/2005
• Status: Active Grant

• Current Assignee: F5 Networks, Inc. (F5 Incorporated)
• Original Assignee: F5 Networks, Inc. (F5 Incorporated)
• Inventors: Skene, Bryan D.
• Primary Examiner(s): Etienne, Ario
• Assistant Examiner(s): Williams, Clayton R
• Application Number:
  US13/084,536
• Time in Patent Office: 862 Days
• Field of Search: None
• US Class Current: 709/227
• CPC Class Codes: H04L 45/12 Shortest path evaluation
• CPC Class Codes: H04L 45/22 Alternate routing
• CPC Class Codes: H04L 67/1001 for accessing one among a plurality of replicated servers

Abstract

A system, apparatus, and method are directed to managing network communications between a client and a server by enabling the client to make decisions involving the selection of alternate network paths. The client and/or the server may be multi-homed to a network. In one embodiment, a link load balancer provides the client with a message and/or path data that enables the client to improve its connections with the server by redirecting network packets using an alternate network path. The message may be based on a static policy at the server, changes in availability of the network connections between the client and server, changes in a quality of the network connections, paths, or the like. Redirecting the network packet by the client may include closing one network connection and establishing another network connection, and/or employing an available alternate network path to re-route network packets towards the server.

Claims

1. A non-transitory computer readable storage device having computer-executable instructions stored thereon, the computer-executable instructions when installed on a client device cause the client device to perform actions, comprising:

establishing a connection over a path to a server, the connection enabling a session between the client device and the server;

collecting path data about a plurality of different possible connections between the client device and the server, the path data including metrics about each of the plurality of different possible connections based on at least one of a network ping, a probe, or a path characteristic that includes at least one of a network device failure indication or a security metric;

selecting a link by evaluating each of the plurality of possible connections based on the collected path data; and

establishing an alternate connection for the session to the same server over the selected link, wherein the alternate connection enables the session between the client device and the same server to be maintained and further preserving a same last hop to the same server for the session.

2. The non-transitory computer readable storage device of claim 1, wherein the computer-executable instructions when installed on a client device cause the client device to perform actions, further comprising receiving information indicating at least one of settings as to which path data to employ or weighting factors to apply to one or more of the path data.

3. The non-transitory computer readable storage device of claim 1, wherein at least some of the path data is collected by peering with another network device.

4. The non-transitory computer readable storage device of claim 1, wherein selecting a link by evaluating the path data further comprises:

determining information about whether the session includes content that is better served by a high-speed link over a low-speed link, whether the session includes a request type that includes a request for a secure connection, a request for a particular type of connection, or a particular type of application; and

further employing the determined information in selecting the link.

5. The non-transitory computer readable storage device of claim 1, wherein establishing the alternate connection further comprises closing the connection to the server, and opening the alternate connection to the same server.

6. The non-transitory computer readable storage device of claim 1, wherein establishing the alternate connection further comprises employing state data stored at the client device about the session for maintaining the session when it is transferred to the alternate connection.

7. A client device, comprising:

a transceiver for receiving and sending packets over a network, the client device being further multi-homed to the network; and

a processor that executes program instructions, including;

establishing a connection over a path to a server, the connection enabling a session between the client device and the server;

collecting path data about a plurality of different possible connections between the client device and the server, the path data including metrics about each of the plurality of different possible connections based on at least one of a network ping, a probe, or a path characteristic that includes at least one of a network device failure indication or a security metric;

selecting a link by evaluating each of the plurality of possible connections based on the collected path data; and

establishing an alternate connection to the same server over the link for the session, wherein the alternate connection enables the session between the client device and the same server to be maintained and further preserving a same last hop to the same server for the session.

8. The client device of claim 7, wherein processor executes program instructions, further including:

receiving information indicating at least one of settings as to which path data to employ or weighting factors to apply to one or more of the path data.

9. The client device of claim 7, wherein at least some of the path data is collected by peering with another network device.

10. The client device of claim 7, wherein selecting a link by evaluating the path data further comprises:

determining information about whether the session includes content that is better served by a high-speed link over a low-speed link, whether the session includes a request type that includes a request for a secure connection, a request for a particular type of connection, or a particular type of application; and

further employing the determined information in selecting the link.

11. The client device of claim 7, wherein establishing the alternate connection further comprises closing the connection to the server, and opening the alternate connection to the same server.

12. The client device of claim 7, wherein the client device further receives a channel control message requesting that the client device change the path to the server.

13. A method of managing a communication over a network, comprising:

establishing a connection over a path to a server device, the connection enabling a session between a multi-homed client device and the server device;

installing onto the client device a redirect agent that executes within the client device and performs actions, including;

collecting path data about a plurality of different possible connections between the client device and the server device, the path data including metrics about each of the plurality of different possible connections based on at least one of a network ping, a probe, or a path characteristic that includes at least one of a network device failure indication or a security metric;

selecting a link by evaluating each of the plurality of possible connections based on the collected path data; and

establishing an alternate connection to the same server device over the link for the session, wherein the alternate connection enables the session between the client device and the same server device to be maintained and further preserving a same last hop to the same server for the session.

14. The method of claim 13, wherein the client device performs actions, further comprising:

receiving information indicating at least one of settings as to which path data to employ or weighting factors to apply to one or more of the path data.

15. The method of claim 13, wherein selecting a link by evaluating the path data further comprises:

determining information about whether the session includes content that is better served by a high-speed link over a low-speed link, whether the session includes a request type that includes a request for a secure connection, a request for a particular type of connection, or a particular type of application; and

further employing the determined information in selecting the link.

16. The method of claim 13, wherein establishing the alternate connection further comprises closing the connection to the server, and opening the alternate connection to the same server.

17. The method of claim 13, wherein establishing the alternate connection to the server device further comprises employing a different network address to the server device from a first network address to the server used in the connection to the server device.