Method and apparatus for facilitating load balancing across name servers

• US 6,871,347 B2
• Filed: 04/13/2001
• Issued: 03/22/2005
• Est. Priority Date: 04/13/2001
• Status: Active Grant

• Current Assignee: Web.com Group, Inc.
• Original Assignee: Interland, Inc. (Web.com Group, Inc.)
• Inventors: Hay, Russell C.
• Primary Examiner(s): Knight, Anthony
• Assistant Examiner(s): BARNES-BULLOCK, CRYSTAL JOY
• Application Number:
  US09/835,312
• Publication Number:
  US 20020152322A1
• Time in Patent Office: 1,439 Days
• Field of Search: 709/203, 709217-219, 709/226, 709/235, 709/238, 709/239, 709/245, 718/100, 718/105, 714 1- 5, 714/10, 714/11, 710 15- 19
• US Class Current: 718/105
• CPC Class Codes: H04L 61/00 Network arrangements, protocols or services for addressing or naming
• CPC Class Codes: H04L 61/45 Network directories; Name-to-address mapping
• 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 67/1034 Reaction to server failures by a load balancer
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

One embodiment of the present invention provides a system that translates host names into Internet Protocol (IP) addresses. This system includes a plurality of name servers that are configured to translate host names into corresponding IP addresses. This system also includes a plurality of load balancers coupled to the plurality of name servers. Each of these load balancers is configured to receive requests for host name translations, and to distribute these requests between the plurality of name servers in order to balance load across the plurality of name servers. Note that these load balancers are configured to operate in parallel in distributing requests between the plurality of name servers. A variation on the above embodiment provides a system that performs failovers between a plurality of load balancers that are configured to balance requests for host name to IP address translations between a plurality of name servers. The system operates by sending a keep alive packet from a load balancer to a first neighboring load balancer, and then waiting for a response to the keep alive packet in order to determine if the first neighboring load balancer remains alive. If the first neighboring load balancer does not remain alive, the load balancer takes over servicing of translation requests directed to the first neighboring load balancer.

Claims

1. An apparatus that translates host names into Internet Protocol (IP) addresses, comprising:

a plurality of name servers, wherein each name server is configured to translate a host name into a corresponding IP address; and

a plurality of load balancers coupled to the plurality of name servers, wherein each load balancer is configured to,

receive requests for host name translations at a load balancer, and to

distribute the requests between the plurality of name servers so as to balance load across the plurality of name servers;

wherein load balancers in the plurality of load balancers are organized into a ring;

wherein each load balancer is configured to take over load balancing operations for a neighboring load balancer in the ring, if the neighboring load balancer fails; and

wherein the plurality of load balancers are configured to operate in parallel in distributing requests between the plurality of name servers.

2. The apparatus of claim 1, wherein each of the plurality of load balancers is associated with its own IP address, and is configured to process translation requests directed to its own IP address.

3. The apparatus of claim 1, wherein each of the plurality of load balancers is configured to take over load balancing operations for one or more failed load balancers in the plurality of load balancers.

4. The apparatus of claim 1, further comprising an internal communication network that couples the plurality of load balancers with the plurality of name servers.

5. The apparatus of claim 1, wherein each load balancer in the plurality of load balancers is a proxy server that is configured to accept user datagram protocol (UDP) and transmission control protocol (TCP) connections from domain name system (DNS) clients, and to forward corresponding UDP or proxy TCP requests to the plurality of name servers.

6. The apparatus of claim 1, wherein each of the plurality of load balancers is configured to distribute translation requests between the plurality of name servers based upon measured response times of the plurality of name servers.

7. A method for translating a host name into an Internet Protocol (IP) address, comprising:

receiving a translation request at a load balancer within a plurality of load balancers to translate the host name into the IP address;

wherein the plurality of load balancers are organized into a ring; and

wherein each load balancer is configured to take over load balancing operations for a neighboring load balancer in the ring, if the neighboring load balancer fails;

selecting a name server from a plurality of name servers to process the translation request based upon a measured load of the plurality of name servers, so that overloaded name servers will not be selected; and

forwarding the translation request to the selected name server so that the selected name server can translate the host name into the IP address.

8. The method of claim 7, further comprising measuring a load on the plurality of name servers by periodically:

sending an information request to each name server in the plurality of name servers; and

measuring a response time to the information request for each name server in the plurality of name servers.

9. The method of claim 7, wherein receiving the translation request involves receiving the translation request at one of a plurality of load balancers, wherein each load balancer is configured to:

receive translation requests for host name translations; and

to

distribute the translation requests between the plurality of name servers so as to balance load across the plurality of name servers.

10. The method of claim 9, wherein each of the plurality of load balancers is associated with its own IP address, and is configured to process translation requests directed to its own IP address.

11. The method of claim 9, further comprising taking over load balancing operations, if necessary, for one or more failed load balancers in the plurality of load balancers.

12. The method of claim 9, wherein each load balancer in the plurality of load balancers is a proxy server that is configured to accept user datagram protocol (UDP) and transmission control protocol (TCP) connections from domain name system (DNS) clients, and to forward corresponding UDP or proxy TCP requests to the plurality of name servers.

13. A method for performing failovers between a plurality of load balancers that are configured to balance requests for host name to IP address translations between a plurality of name servers that are coupled to the plurality of load balancers, comprising:

sending a keep alive packet to a first neighboring load balancer in the plurality of load balancers;

wherein the plurality of load balancers are organized into a ring; and

wherein each load balancer in the plurality of load balancers is configured to take over load balancing operations for a neighboring load balancer in the ring, if the neighboring load balancer fails;

waiting for a response to the keep alive packet in order to determine if the first neighboring load balancer remains alive;

if the first neighboring load balancer does not remain alive, taking over servicing of translation requests directed to the first neighboring load balancer.

14. The method of claim 13, further comprising distributing translation requests between the plurality of name servers based upon measured response times of the plurality of name servers.

15. The method of claim 13, wherein each load balancer in the plurality of load balancers is a proxy server that is configured to accept user datagram protocol (UDP) and transmission control protocol (TCP) connections from domain name system (DNS) clients, and to forward corresponding UDP or proxy TCP requests to the plurality of name servers.

16. The method of claim 13, further comprising:

receiving a second keep alive packet from a second neighboring load balancer in the plurality of load balancers; and

sending a response to the second keep alive packet to the second neighboring load balancer.

17. The method of claim 15, wherein each of the plurality of load balancers is associated with its own IP address, and is configured to process translation requests directed its own IP address.

18. An apparatus that translates host names into Internet Protocol (IP) addresses, comprising:

a plurality of name servers, wherein each name server is configured to translate a host name into a corresponding IP address; and

a plurality of load balancers coupled to the plurality of name servers, wherein each load balancer is configured to,

receive requests for host name translations at a load balancer, and to

distribute the requests between the plurality of name servers so as to balance load across the plurality of name servers;

wherein the plurality of load balancers are configured to operate in parallel in distributing requests between the plurality of name servers;

wherein the plurality of load balancers are organized into a ring;

wherein each of the plurality of load balancers is configured to take over load balancing operations for one or more failed load balancers in the plurality of load balancers; and

wherein each of the plurality of load balancers is configured to distribute translation requests between the plurality of name servers based upon measured response times of the plurality of name servers.

19. A method for translating a host name into an Internet Protocol (IP) address, comprising:

receiving a translation request at one of a plurality of load balancers to translate the host name into the IP address;

selecting a name server from a plurality of name servers to process the translation request based upon a measured load of the plurality of name servers, so that overloaded name servers will not be selected;

forwarding the translation request to the selected name server from the load balancer so that the selected name server can translate the host name into the IP address; and

taking over load balancing operations, if necessary, for one or more failed load balancers in the plurality of load balancers;

wherein the plurality of load balancers are organized into a ring;

wherein each load balancer is configured to distribute the translation requests between the plurality of name servers so as to balance load across the plurality of name servers.

20. A method for performing failovers between a plurality of load balancers that are configured to balance requests for host name to IP address translations between a plurality of name servers that are coupled to the plurality of load balancers, comprising:

distributing translation requests between the plurality of name servers based upon measured response times of the plurality of name servers;

sending a keep alive packet to a first neighboring load balancer in the plurality of load balancers;

wherein the plurality of load balancers are organized into a ring; and

wherein each load balancer in the plurality of load balancers is configured to take over load balancing operations for a neighboring load balancer in the ring, if the neighboring load balancer fails;

waiting for a response to the keep alive packet in order to determine if first neighboring load balancer remains alive;

if the first neighboring load balancer does not remain alive, taking over servicing of translation requests directed to the first neighboring load balancer;

receiving a second keep alive packet from a second neighboring load balancer in the plurality of load balancers; and

sending a response to the second keep alive packet to the second neighboring load balancer.