Method, apparatus, and program for server based network computer load balancing across multiple boot servers

• US 20020078188A1
• Filed: 12/18/2000
• Published: 06/20/2002
• Est. Priority Date: 12/18/2000
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Anand, Vaijayanthimala K., French, Steven Michael, Paul, Chakkalamattam Jos, Schoech, James Richard, Stern, Bradford Allen
• Granted Patent: US 7,139,816 B2
• Time in Patent Office: Days
• US Class Current: 709/222
• CPC Class Codes: G06F 11/1417 Boot up procedures
• CPC Class Codes: G06F 11/2023 Failover techniques
• CPC Class Codes: G06F 11/2035 without idle spare hardware
• CPC Class Codes: G06F 9/4416 Network booting; Remote initial program loading [RIPL]

Abstract

A method, system, and program is provided to redirect a client computer to an appropriate boot server after it has been directed to any initial boot server by preboot execution environment (PXE) or similar services. An apparatus includes a data file containing a set of addresses of managed boot servers in any syntax and a program file containing a network bootstrap program (NBP) that interprets the syntax of the data file. These files are placed on every initial boot server. The NBP requests a file from the initial boot server whose name is identified with the client computer. The initial boot server will not return that file if it is not an appropriate server for booting the client. In that case, the NBP requests the data file containing the boot server addresses. The NBP then polls each of those boot servers by requesting the client'"'"'s unique file. A boot server that returns the file is an appropriate boot server for the client computer. The data file containing boot server addresses is changed to reflect current boot server load balancing requirements without involving the configuration or affecting the availability of PXE or similar services.

Claims

1. A method for retrieving client boot information in a network environment with multiple boot servers, comprising:

sending an initial request for client configuration information to a first boot server;

if the client configuration information is not found on the first boot server, sending a list request for a boot server list to the first boot server;

receiving the boot server list; and

sending a configuration information request for the client configuration information to each server in the boot server list until the client configuration information is found or a request has been sent to every server in the boot server list.

2. The method of claim 1, wherein at least one of the initial request, the list request, and the configuration information request is a trivial file transfer protocol request.

3. The method of claim 1, further comprising:

receiving, from the first boot server, an error message that indicates that the client information is not found on the first boot server.

4. The method of claim 1, further comprising:

receiving the client configuration information from an associated boot server in response to the client configuration information being found.

5. The method of claim 4, further comprising:

sending a boot file request for remaining boot files to the associated boot server based on the client configuration information.

6. The method of claim 1, further comprising:

determining whether the entries in the boot server list were pre-ordered, in order to better support load balancing among boot servers, prior to transmission to the client; and

if the list is found to be ordered, sending a configuration information request for the client configuration information to each server in the boot server list in the order given.

7. The method of claim 1, further comprising:

sending a configuration information request for the client configuration information to each server in the boot server list in order of increasing network distance, where distance is estimated from available network configuration information when there was no indication that the order of the original boot server list was optimized in order to better support load balancing.

8. The method of claim 1, wherein the method is performed by a network bootstrap program.

9. The method of claim 1, wherein the method is performed on a client computer.

10. A method for providing client boot information in a network environment with multiple boot servers, comprising:

receiving an initial request for client configuration information from a client;

if the client configuration information is not found, sending an error message that indicates that the client information is not found;

receiving a list request for a boot server list from the client; and

sending the boot server list to the client.

11. The method of claim 10, wherein at least one of the initial request and the list request is a trivial file transfer protocol request.

12. The method of claim 10, further comprising:

adding an indication to the boot server list to inform the client that the list is being provided in optimal order to support load balancing among boot servers.

13. The method of claim 10, wherein the method is performed on a boot server.

15. The apparatus of claim 14, wherein at least one of the initial request, the list request, and the configuration information request is a trivial file transfer protocol request.

16. The apparatus of claim 14, further comprising:

means for receiving, from the first boot server, an error message that indicates that the client information is not found on the first boot server.

17. The apparatus of claim 14, further comprising:

means for receiving the client configuration information from an associated boot server in response to the client configuration information being found; and

means for sending a boot file request for remaining boot files to the associated boot server based on the client configuration information.

18. The apparatus of claim 14, further comprising:

means for determining whether the entries in the boot server list were pre-ordered, in order to better support load balancing among boot servers, prior to transmission to the client; and

if the list is found to be ordered, means for sending a configuration information request for the client configuration information to each server in the boot server list in the order given.

19. The apparatus of claim 14, further comprising:

means for sending a configuration information request for the client configuration information to each server in the boot server list in order of increasing network distance, where distance is estimated from available network configuration information when there was no indication that the order of the original boot server list was optimized in order to better support load balancing.

20. The apparatus of claim 14, wherein the apparatus is client computer running a network bootstrap program.

14. An apparatus for retrieving client boot information in a network environment with multiple boot servers, comprising:

first sending means for sending an initial request for client configuration information to a first boot server;

second sending means for sending a list request for a boot server list to the first boot server if the client configuration information is not found on the first boot server;

receipt means for receiving the boot server list; and

third sending means for sending a configuration information request for the client configuration information to each server in the boot server list until the client configuration information is found or a request has been sent to every server in the boot server list.

21. An apparatus for providing client boot information in a network environment with multiple boot servers, comprising:

first receipt means for receiving an initial request for client configuration information from a client;

first sending means for sending an error message that indicates that the client information is not found if the client configuration information is not found;

second receipt means for receiving a list request for a boot server list from the client; and

second sending means for sending the boot server list to the client.

22. The apparatus of claim 21, wherein at least one of the initial request and the list request is a trivial file transfer protocol request.

23. The apparatus of claim 21, further comprising:

means for adding an indication to the boot server list to inform the client that the list is given in optimal order to support load balancing among boot servers.

24. The apparatus of claim 21, wherein the apparatus is a boot server.

25. A computer program product, in a computer readable medium, for retrieving client boot information in a network environment with multiple boot servers, comprising:

instructions for sending an initial request for client configuration information to a first boot server;

instructions for sending a list request for a boot server list to the first boot server if the client configuration information is not found on the first boot server;

instructions for receiving the boot server list; and

instructions for sending a configuration information request for the client configuration information to each server in the boot server list until the client configuration information is found or a request has been sent to every server in the boot server list.

26. A computer program product, in a computer readable medium, for providing client boot information in a network environment with multiple boot servers, comprising:

instructions for receiving an initial request for client configuration information from a client;

instructions for sending an error message that indicates that the client information is not found if the client configuration information is not found;

instructions for receiving a list request for a boot server list from the client; and

instructions for sending the boot server list to the client.