SERVER SELECTION FOR ROUTING CONTENT TO A CLIENT USING APPLICATION LAYER REDIRECTION

• US 20090234968A1
• Filed: 03/13/2008
• Published: 09/17/2009
• Est. Priority Date: 03/13/2008
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Viveganandhan, Mahesh Chakravarthy Vittal, Thomas, Anil, Koroth, Dipak Punnoran
• Granted Patent: US 8,667,175 B2
• Time in Patent Office: Days
• US Class Current: 709/241
• CPC Class Codes: H04L 65/612 for unicast
• CPC Class Codes: H04L 65/613 for the control of the source by the destination control signals issued by the client directed to the server or network components specially adapted for selective content distribution H04N21/637
• CPC Class Codes: H04L 65/65 Network streaming protocols, e.g. real-time transport protocol [RTP] or real-time control protocol [RTCP]
• CPC Class Codes: H04L 65/752 adapting media to network capabilities
• CPC Class Codes: H04L 65/80 Responding to QoS
• CPC Class Codes: H04L 67/1001 for accessing one among a plurality of replicated servers
• CPC Class Codes: H04L 67/1008 based on parameters of servers, e.g. available memory or workload monitoring of computer activity G06F11/30
• CPC Class Codes: H04L 67/101 based on network conditions
• CPC Class Codes: H04L 67/1012 based on compliance of requirements or conditions with available server resources
• CPC Class Codes: H04L 67/1021 based on client or server locations
• CPC Class Codes: H04L 67/1029 using data related to the state of servers by a load balancer
• CPC Class Codes: H04L 67/61 taking into account QoS or priority requirements

Abstract

In one embodiment, a first request is received for a probe link from a client that has downloaded a page. The request is received from an application. A test may be performed to determine a server that could optimally service a content request from the client. After receiving the request, the content router sends a re-direct to the client where the re-direct causes the client to follow the re-direct to the server. The server then sends a re-direct back to the client, which the client follows by sending a second request to the content router. The second request is associated with the client and the round-trip time is calculated for the server. It is then determined if the location for the server should be designated as the content deliverer to the client based on the calculated round-trip time.

Claims

1. A method comprising:

receiving a first request for a probe link from a client that has downloaded a page;

determining a server in a location, the location being a location that could service a content request from the client;

sending a redirect message to the client, the redirect message causing the client to follow the redirect message to the server and to receive a redirect back to the client;

receiving a second request from the client based on the redirect received from the server at the client;

associating the second request with the probe link;

calculating a roundtrip time for the server; and

determining if the location should be designated as a content deliverer to the client based on the calculated roundtrip time.

2. The method of claim 1, further comprising:

calculating a plurality of roundtrip times for a plurality of locations; and

determining a location in the plurality of locations as the content deliverer based on the calculated roundtrip times.

3. The method of claim 1, further comprising:

sending a plurality of redirect messages to the client for a plurality of locations; and

determining a location in the plurality of locations as the content deliverer based on which second request from a server the location is received first.

4. The method of claim 1, wherein the redirect message is a redirect message that passes through a client'"'"'s firewall.

5. The method of claim 1, wherein the first request is received from an application at the client.

6. The method of claim 1, wherein the content deliverer is determined before a content request for content is received.

7. The method of claim 6, further comprising redirecting the client to the determined location when the content request is received.

8. The method of claim 1, wherein the roundtrip time is based on a time the redirect message is sent to the client and when the second request is received.

9. The method of claim 1, wherein the redirect message causes a file to be downloaded from the server.

10. An apparatus comprising:

one or more processors; and

logic encoded in one or more tangible media for execution by the one or more processors and when executed operable to;

receive a first request for a probe link from a client that has downloaded a page;

determine a server in a location, the location being a location that could service a content request from the client;

send a redirect message to the client, the redirect message causing the client to follow the redirect message to the server and to receive a redirect back to the client;

receive a second request from the client based on the redirect received from the server at the client;

associate the second request with the probe link;

calculate a roundtrip time for the server; and

determine if the location should be designated as a content deliverer to the client based on the calculated roundtrip time.

11. The apparatus of claim 10, wherein the logic when executed is further operable to:

calculate a plurality of roundtrip times for a plurality of locations; and

determine a location in the plurality of locations as the content deliverer based on the calculated roundtrip times.

12. The apparatus of claim 10, wherein the logic when executed is further operable to:

send a plurality of redirect messages to the client for a plurality of locations; and

determine a location in the plurality of locations as the content deliverer based on which second request from a server the location is received first.

13. The apparatus of claim 10, wherein the redirect message is a redirect message that passes through a client'"'"'s firewall.

14. The apparatus of claim 10, wherein the first request is received from an application at the client.

15. The apparatus of claim 10, wherein the content deliverer is determined before a content request for content is received.

16. The apparatus of claim 15, wherein the logic when executed is further operable to redirect the client to the determined location when the content request is received.

17. The apparatus of claim 10, wherein the roundtrip time is based on a time the redirect message is sent to the client and when the second request is received.

18. The apparatus of claim 10, wherein the redirect message causes a file to be downloaded from the server.

19. An apparatus comprising:

means for receiving a first request for a probe link from a client that has downloaded a page;

means for determining a server in a location, the location being a location that could service a content request from the client;

means for sending a redirect message to the client, the redirect message causing the client to follow the redirect message to the server and to receive a redirect back to the client;

means for receiving a second request from the client based on the redirect received from the server at the client;

means for associating the second request with the probe link;

means for calculating a roundtrip time for the server; and

means for determining if the location should be designated as a content deliverer to the client based on the calculated roundtrip time.

20. The apparatus of claim 19, further comprising:

means for calculating a plurality of roundtrip times for a plurality of locations; and

means for determining a location in the plurality of locations as the content deliverer based on the calculated roundtrip times.