Multipath routing process

• US 20070094361A1
• Filed: 10/25/2005
• Published: 04/26/2007
• Est. Priority Date: 10/25/2005
• Status: Active Grant

• Current Assignee: Oracle International Corporation (Oracle Corporation)
• Original Assignee: Oracle International Corporation (Oracle Corporation)
• Inventors: Hirschberg, Daniel, Hoynowski, Charles
• Granted Patent: US 8,166,197 B2
• Time in Patent Office: Days
• US Class Current: 709/220
• CPC Class Codes: G06F 11/1443 Transmit or communication errors
• CPC Class Codes: G06F 11/2023 Failover techniques
• CPC Class Codes: G06F 11/2048 where the redundant components share neither address space nor persistent storage
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04L 45/20 Hop count for routing purposes, e.g. TTL
• CPC Class Codes: H04L 45/22 Alternate routing
• CPC Class Codes: H04L 45/247 using M:N active or standby paths
• CPC Class Codes: H04L 61/4511 using domain name system [DNS]
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04L 67/1001 for accessing one among a plurality of replicated servers
• CPC Class Codes: H04L 67/101 based on network conditions

Abstract

Methods and apparatus that enable more than one server to host a resource using a shared IP address such that a client may generally access the resource on any of the servers using the shared IP address are disclosed. According to one aspect of the present invention, a method for providing paths that allow a client to access a resource in a TCP/IP network includes obtaining an IP address, as well as associating the IP address to first and second servers. The first and second servers support the resource at the IP address, and a first path of the plurality of paths that allow the client to access the resource is between the client and the first server and a second path of the plurality of paths that allow the client to access the resource is between the client and the second server.

Claims

1. A method for providing a plurality of paths that allow a client to access a website in a TCP/IP network, the method comprising:

obtaining an IP address; and

associating the IP address to a first server and to a second server, the first server being arranged to support the website at the IP address and the second server being arranged to support the website at the IP address, wherein a first path of the plurality of paths that allow the client to access the website is between the client and the first server and a second path of the plurality of paths that allow the client to access the website is between the client and the second server.

2. The method of claim 1 wherein the website has an associated domain name and obtaining the IP address includes associating the domain name to the IP address.

3. The method of claim 2 wherein the first server is a part of a first autonomous system and the second server is a part of a second autonomous system.

4. The method of claim 2 further including:

initiating a TCP session between the client and one of the first server and the second server to allow the client to access the website.

5. The method of claim 4 wherein initiating the TCP session includes:

determining whether to use the first path to allow the client to access the website at the IP address on the first server; and

using the first path to allow the client to access the website when it is determined that the first path is to be used to allow the client to access the website at the IP address on the first server.

6. The method of claim 5 wherein determining whether to use the first path to allow the client to access the website at the IP address on the first server includes determining at least a first cost associated with the first path and a second cost associated with the second path, and determining when the first cost is lower than the second cost.

7. The method of claim 5 wherein determining whether to use the first path to allow the client to access the website at the IP address on the first server includes determining at least a first distance associated with the first path and a second distance associated with the second path, and determining when the first path is shorter than the second path.

8. The method of claim 5 wherein determining whether to use the first path to allow the client to access the website at the IP address on the first server includes determining when the first path is active while the second path is not active.

9. The method of claim 5 wherein using the first path to allow the client to access the website when it is determined that the first path is to be used to allow the client to access the website at the IP address on the first server includes using the first path until the first path becomes unusable, the method further including:

using the second path to allow the client to access the website when the first path becomes unusable.

10. The method of claim 4 wherein initiating the TCP session includes:

obtaining the IP address from a DNS server; and

providing the IP address to a gateway router.

11. A computer program product for providing a plurality of paths that allow a client to access a website in a TCP/IP network, the computer program product comprising:

code devices that cause an IP address to be obtained;

code devices that cause the IP address to be associated to a first server and to a second server, the first server being arranged to support the website at the IP address and the second server being arranged to support the website at the IP address, wherein a first path of the plurality of paths that allow the client to access the website is between the client and the first server and a second path of the plurality of paths that allow the client to access the website is between the client and the second server; and

a computer-readable medium that stores the computer codes.

12. The computer program product of claim 11 wherein the website has an associated domain name and the code devices that cause the IP address to be obtained include code devices that cause the domain name to be associated to the IP address.

13. The computer program product of claim 12 further including:

code devices that cause a TCP session between the client and one of the first server and the second server to allow the client to access the website to be initiated.

14. The computer program product of claim 13 wherein the code devices that cause the TCP session to be initiated include:

code devices that cause a determination of whether to use the first path to allow the client to access the website at the IP address on the first server; and

code devices that cause the first path to be used to allow the client to access the website when it is determined that the first path is to be used to allow the client to access the website at the IP address on the first server.

15. The computer program product of claim 13 wherein the code devices that cause a determination of whether to use the first path to allow the client to access the website at the IP address on the first server include code devices that cause a determination of at least a first cost associated with the first path and a second cost associated with the second path, and code devices that cause a determination of whether the first cost is lower than the second cost.

16. The computer program product of claim 13 wherein the code devices that cause a determination of whether to use the first path to allow the client to access the website at the IP address on the first server include code devices that cause a determination of at least a first distance associated with the first path and a second distance associated with the second path, and code devices that cause a determination of when the first path is shorter than the second path.

17. The computer program product of claim 13 wherein the code devices that cause a determination of whether to use the first path to allow the client to access the website at the IP address on the first server include code devices that cause a determination of when the first path is active while the second path is not active.

18. A system for providing a plurality of paths that allow a client to access a website in a TCP/IP network, the system comprising:

means for obtaining an IP address; and

means for associating the IP address to a first server and to a second server, the first server being arranged to support the website at the IP address and the second server being arranged to support the website at the IP address, wherein a first path of the plurality of paths that allow the client to access the website is between the client and the first server and a second path of the plurality of paths that allow the client to access the website is between the client and the second server.

19. The system of claim 18 wherein the website has an associated domain name and the means for obtaining the IP address include means for associating the domain name to an IP address.

20. The system of claim 19 further including:

means for initiating a TCP session between the client and one of the first server and the second server to allow the client to access the website.

21. The system of claim 20 wherein the means for initiating the TCP session include:

means for determining whether to use the first path to allow the client to access the website at the IP address on the first server; and

means for using the first path to allow the client to access the website when it is determined that the first path is to be used to allow the client to access the website at the IP address on the first server.

22. The system of claim 21 wherein the means for determining whether to use the first path to allow the client to access the website at the IP address on the first server include means for determining at least a first parameter associated with the first path and a second parameter associated with the second path, and means for determining when the first parameter is less than the second parameter.

23. The system of claim 21 wherein the means for determining whether to use the first path to allow the client to access the website at the IP address on the first server include means for determining when the first path is active while the second path is not active.

24. An apparatus for providing a client with access to a resource, the resource being associated with a domain name, the apparatus comprising:

a server arrangement, the server arrangement being arranged to receive a request from the client to provide an IP address associated with the resource, wherein the server arrangement is arranged to translate the domain name into the IP address; and

a router arrangement, the router arrangement being arranged to provide the client with access to one of a plurality of servers associated with the IP address, wherein each one of the plurality of servers associated with the IP address is arranged to host the resource using the IP address.

25. The apparatus of claim 24 wherein a first path of a plurality of paths is arranged between the client and a first server of the plurality of servers, and a second path of the plurality of paths is arranged between the client and a second server of the plurality of servers, and wherein the router arrangement is arranged to select one of the first path and the second path for use in providing the client with access to the resource.

26. The apparatus of claim 25 wherein the router arrangement includes a router and a load balancer, the load balancer being arranged to cooperate with the router to select the first path for use in providing the client with access to the resource when the first path is approximately the least loaded of the plurality of paths.

27. The apparatus of claim 25 wherein the router arrangement is arranged to select the first path for use in providing the client with access to the resource when the first path is substantially the only available path of the plurality of paths.

28. The apparatus of claim 25 wherein the router arrangement is arranged to select the first path for use in providing the client with access to the resource when the first path has substantially the lowest cost of the plurality of paths.

29. The apparatus of claim 25 wherein the router arrangement is arranged to select the first path for use in providing the client with access to the resource when the first server is physically closer to the client than the second server.

30. A method for providing a client with access to a resource, the resource being associated with a domain name, the method comprising:

receiving a request to access an IP address associated with the domain name, wherein the IP address is further associated with a plurality of servers arranged to host the resource at the IP address;

identifying a first server of the plurality of servers for use in establishing a TCP session for the client to access the resource at the IP address; and

establishing the TCP session between the client and the first server.

31. The method of claim 30 wherein identifying the first server for use in establishing the TCP session includes at least one of identifying when a first path between the client and the first server has a lower cost than a second path between the client and a second server, identifying when the first path is active and the second path is inactive, identifying when the client is physically closer to the first server than to the second server, and identifying when the first server has a lighter load than the second server.