Method and apparatus for global server load balancing

• US 20030229697A1
• Filed: 06/10/2002
• Published: 12/11/2003
• Est. Priority Date: 06/10/2002
• Status: Active Grant

• Current Assignee: UTStarcom Incorporated (UTStarcom Holdings Corp.)
• Original Assignee: 3Com Corporation (HP Inc.)
• Inventors: Borella, Michael S.
• Granted Patent: US 7,305,429 B2
• Time in Patent Office: Days
• US Class Current: 709/226
• CPC Class Codes: H04L 61/35 involving non-standard use of addresses for implementing network functionalities, e.g. coding subscription information within the address or functional addressing, i.e. assigning an address to a function
• CPC Class Codes: H04L 61/4511 using domain name system [DNS]
• CPC Class Codes: H04L 61/5084 Providing for device mobility network addressing or numbering for mobility support in wireless networks H04W8/26; mobile IP H04W80/04
• CPC Class Codes: H04L 63/08 for authentication of entities cryptographic mechanisms or cryptographic arrangements for entity authentication H04L9/32
• CPC Class Codes: H04L 67/1001 for accessing one among a plurality of replicated servers
• CPC Class Codes: H04L 67/10015 Access to distributed or replicated servers, e.g. using brokers
• 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 67/1038 Load balancing arrangements to avoid a single path through a load balancer
• CPC Class Codes: H04L 9/40 Network security protocols
• CPC Class Codes: H04W 80/04 Network layer protocols, e.g. mobile IP [Internet Protocol]

Abstract

A system and method are shown for load balancing across global network resources using an existing network protocol, such as Mobile IP, having a redirect feature. According to one method, each of a plurality of servers at a data center uses Mobile IP to obtain an IP address that is also provided to a content server site. Further, a content server site includes a plurality of IP addresses assigned to the plurality of servers and creates a load database including load data for each server. When a client request is received at the content server site from a client device, the content server site determines a network address of a server to process the client request based on the load data, and provides the network address of the server to the client device. When the client device receives the network address of the server, the client device sends an application request to the selected server, and the selected server sends an application response to the client device.

Claims

1. A method for dynamic network address assignment to a plurality of servers at a data center, the method comprising:

providing a plurality of foreign agents at the data center; and

using a Mobile Internet Protocol to dynamically assign a network address to each of the plurality of servers at the data center.

2. The method of claim 1, further comprising providing a plurality of home agents at a content owner server site, wherein using the Mobile Internet Protocol to dynamically assign a network address to each of the plurality of servers at the data center comprises:

selecting a foreign agent for each of the plurality of servers;

sending a registration request message comprising a request for a network address assignment from each server to the selected foreign agent;

determining a home agent to service the registration request, wherein the home agent is selected from the plurality of home agents;

forwarding the registration request message from the foreign agent to the selected home agent;

allocating a network address to the server at the home agent; and

providing the network address to the server.

3. The method of claim 2, wherein determining a home agent to service the registration request comprises:

sending an access request message from the selected foreign agent to an authorization, authentication and accounting server;

determining a network address of the home agent at the authorization, authentication and accounting server; and

sending an access response message from the authorization, authentication and accounting server to the foreign agent, wherein the access response comprises the network address of the home agent.

4. The method of claim 2, wherein determining a home agent to service the registration request comprises:

sending an access request message from the selected foreign agent to an authorization, authentication and accounting server;

sending an access response message from the authorization, authentication and accounting server to the foreign agent, wherein the access response message comprises instructions for the selected foreign agent to assign a home agent address from a predetermined pool of home agent addresses; and

determining a network address of a home agent at the foreign agent based on the instructions provided from the authorization, authentication and accounting server.

5. The method of claim 2, further comprising:

receiving a domain name request from a client device at the content owner site;

selecting one of the plurality of servers to service the request;

providing a network IP address of the selected server to the client device; and

using a redirect feature of the Mobile Internet Protocol to route an application request from the client device to the selected server.

6. The method of claim 5, further comprising:

receiving the application request at the selected server;

processing the application request to form an application response to the application request; and

sending the application response from the selected server to the client device.

8. A method for load balancing between servers coupled to a network, the method comprising:

using a network protocol to dynamically assign a network address to each of a plurality of servers;

maintaining at a content owner site server load data and the network address of each of the plurality of servers;

receiving a client request from a client device at the content owner site server, wherein the client request is addressed to a virtual network address of the content owner site server;

using the load data of the plurality of servers to determine a selected server from the plurality of servers;

sending a client response from the content owner site to the client device, the client response comprising a network address of the selected server; and

sending an application request from the client device to the selected server using a redirect feature of the network protocol, wherein routing information for the network address of the selected server causes the application request to be sent to a redirection device for further routing to the selected server.

9. The method of claim 8, wherein the redirection device comprises a home agent, wherein the network protocol comprises Mobile IP, and using a network protocol to dynamically assign a network address to each of a plurality of servers comprises:

selecting a foreign agent;

sending a registration request message comprising a request for a dynamic network address assignment to the selected foreign agent;

selecting the home agent to process the registration request message;

forwarding the registration request message to the selected home agent;

allocating a network address for a server identified in the registration request at the selected home agent; and

sending a registration request response message comprising the allocated network address from the home agent to the server.

10. The method of claim 9, wherein selecting the home agent at the foreign agent comprises:

sending an access request message from the foreign agent to an authorization, authentication and accounting server;

determining the home agent at the authorization, authentication and accounting server; and

sending an access accept message from the authorization, authentication and accounting server to the foreign agent, the access accept message comprising a network address of the home agent.

11. The method of claim 9, further comprising:

sending an update message from the home agent to the content owner site server, the update message comprising the network address assigned to the server.

12. The method of claim 9, wherein sending an application request from the client device to the selected server using a redirect feature of the existing network protocol comprises:

routing the application request to the selected server via the home agent and the foreign agent assigned to the selected server.

13. The method of claim 8, further comprising:

receiving the application request at the selected server;

processing the application request to form an application response to the application request; and

sending the application response from the selected server to the client device.

14. The method of claim 13, wherein sending the application response from the selected server to the client device comprises:

sending the application response from the client device to a foreign agent;

routing the application response from a foreign agent to a home agent; and

routing the application response from the home agent to the client device.

15. The method of claim 13, further comprising:

sending a binding update message to the client device, wherein the binding update message comprises a care-of-address field set to the network address of a foreign agent.

16. The method of claim 14, further comprising:

receiving a next application request from the client device to the selected network server at the foreign agent;

routing the next application request from the foreign agent to the selected server; and

sending a next application response from the selected server to the client device.

17. A method for load balancing between a plurality of servers at a data center, the method comprising:

providing a foreign agent at the data center;

providing a home agent at a content owner site;

using a mobile IP mechanism to dynamically allocate a plurality of network addresses to the plurality of servers;

maintaining load data and the plurality of network addresses of the plurality of servers at a content owner site server;

receiving a client request message from a client device at the content owner site server;

using the load data to determine a selected server from the plurality of servers; and

sending a client response message from the content owner site server to the client device, wherein the client response message comprises a network address of the selected server.

18. The method of claim 17, further comprising:

sending an application request from the client device to the selected server, wherein sending the application request to the selected server comprises routing the application request via the home agent and the foreign agent.

19. The method of claim 18, further comprising sending an application response from the selected server to the client device.

20. A system for processing client requests over a network, the system comprising:

a data center comprising a plurality of servers and at least one foreign agent, each server being configured to use a mobile IP to dynamically receive a network address, each of the plurality of servers being configured to process a client application request from a client device to form an application response and to transmit the application response to the client device;

a content server site having a first virtual network address, the content server site configured to obtain network addresses of the plurality of servers at the data center, the content server site further comprising load data of the plurality of server, the content server site being further configured to receive a client request from the client device, wherein the client request is addressed to the first virtual network address, and, responsive thereto, determine a selected server from the plurality of servers using the load data for the plurality of servers, and send a client response to the client device, wherein the client response comprises a network address of the selected server.

21. The system of claim 20, wherein the content server site further comprises at least one home agent, and wherein each server is configured to send a registration request message to a foreign agent of the at least one foreign agent, wherein the foreign agent selects a home agent from the at least one home agent and forwards the registration request to the selected home agent, and wherein the selected home agent assigns a network address to a server specified in the registration request, wherein the selected home agent sends a registration response message to the server, and wherein the registration response message comprises the network address assigned to the server.

22. The system of claim 21, wherein the content server site is configured to obtain network addresses of the plurality of servers at the data center from the at least one home agent assigning the network addresses to the plurality of servers.

23. The system of claim 21, wherein each server of the plurality of servers is further configured to send a binding update message to the client device, wherein the binding update message comprises a care-of-address field set to a network address of the selected foreign agent.

24. The system of claim 20, wherein the content server site is further configured to store information associating the client device sending the client application request with the selected server, and wherein the content server site is still further configured to receive a subsequent client application request from the client device and, responsively thereto, retrieve the stored information associating the client device sending the client request with the selected server, and forward the subsequent client application request to the selected server identified in the stored information.

25. A server at a data center, the server configured to use a mobile IP to dynamically receive a network address, the server further configured to receive an application request from a client device and send an application request to the client device.

26. The server of claim 25, wherein the server is configured to select a foreign agent, send a registration request comprising a request for a network address, wherein the foreign agent responsively determines a home agent to process the registration request and sends the registration request to the selected home agent, wherein the home agent responsively assigns a network address to the server and sends a registration response comprising the network address to the server, and wherein the server is further configured to receive the registration response, and responsively use the network address to communicate with the client device.