TECHNIQUE FOR ADDRESSING A CLUSTER OF NETWORK SERVERS

• US 20090144444A1
• Filed: 12/10/2008
• Published: 06/04/2009
• Est. Priority Date: 10/25/2002
• Status: Active Grant

• Current Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Original Assignee: International Business Machines Corporation
• Inventors: Chauffour, Pascal, Lebrun, Eric, Mahe, Valerie
• Granted Patent: US 7,991,914 B2
• Time in Patent Office: Days
• US Class Current: 709/238
• CPC Class Codes: H04L 61/00 Network arrangements, protocols or services for addressing or naming
• CPC Class Codes: H04L 61/25 of the same type
• CPC Class Codes: H04L 61/2514 between local and global IP addresses
• CPC Class Codes: H04L 61/2532 Clique of NAT servers
• CPC Class Codes: H04L 63/0209 Architectural arrangements, e.g. perimeter networks or demilitarized zones
• 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 67/1029 using data related to the state of servers by a load balancer
• CPC Class Codes: H04L 67/1031 Controlling of the operation of servers by a load balancer, e.g. adding or removing servers that serve requests
• CPC Class Codes: H04L 67/1034 Reaction to server failures by a load balancer
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

A single firewall or cluster of firewalls with a public IP address is interfaced to an internet public subnet to receive service requests for a cluster of network servers. A first private subnet with a plurality of private IP addresses is interfaced to the single firewall or cluster of firewalls to receive the service requests after passing through a firewall. A plurality of redundant load balancers with a respective plurality of private IP addresses are interfaced to the first private subnet to receive the service requests after passing through the first private subnet. The load balancers are interfaced to a second private subnet. The network servers with respective private IP addresses are interfaced to the second private subnet to receive the service requests from the load balancers. At an initialization time, a private IP address is defined for the network load balancer system within the internet access subnet. When one of the load balancers becomes primary at the initialization time or switches from a standby state to an active state, the network load balancer system private IP address is defined as an alias in an interface table to be recognized by the one load balancer. When the one network load balancer switches from the active state to a standby state, the network load balancer system private IP address previously defined as the alias is released from the interface table.

Claims

1. A plurality of load balancers for accessing a cluster of servers wherein one or more routing devices are coupled to a public network, a first private subnet is logically interposed between said one or more routing devices and said plurality of load balancers, and a second private network is logically interposed between said plurality of load balancers and said cluster of servers, each of said load balancers comprising:

a central processing unit;

a computer readable storage media;

program instructions to define, at an initialization time, a private IP address within the public network for said plurality of load balancers, and in response to one of said load balancers becoming primary at said initialization time, to define said private IP address as an alias in an interface table to be recognized by said one load balancer, and in response to said one load balancer switching from an active state to a standby state, to release from said interface table said private IP address previously defined as said alias; and

wherein

said program instructions are stored on said computer readable storage media for execution by said central processing unit.

2. A load balancer as set forth in claim 1 wherein said one or more routing devices have one or more respective private IP addresses.

3. A plurality of load balancers for accessing a cluster of servers wherein one or more routing devices are coupled to a public network, a first private subnet is logically interposed between said one or more routing devices and said plurality of load balancers, and a second private network is logically interposed between said plurality of load balancers and said cluster of servers, each of said load balancers comprising:

a central processing unit;

a computer readable storage media;

program instructions to define, at an initialization time, a private IP address within the public network for said plurality of load balancers, and in response to one of said load balancers switching from a standby state to an active state, to define said private IP address as an alias in an interface table to be recognized by said one load balancer, and in response to said one load balancer switching from an active state to a standby state, to release from said interface table said private IP address previously defined as said alias; and

wherein

said program instructions are stored on said computer readable storage media for execution by said central processing unit.

4. A load balancer as set forth in claim 3 wherein said one or more routing devices have one or more respective private IP addresses.

5. A computer program product for each of a plurality of load balancers for accessing a cluster of servers wherein one or more routing devices are coupled to a public network, a first private subnet is logically interposed between said one or more routing devices and said plurality of load balancers, and a second private network is logically interposed between said plurality of load balancers and said cluster of servers, said computer program product comprising:

program instructions to define, at an initialization time, a private IP address within the public network for said plurality of load balancers, and in response to one of said load balancers becoming primary at said initialization time, to define said private IP address as an alias in an interface table to be recognized by said one load balancer, and in response to said one load balancer switching from an active state to a standby state, to release from said interface table said private IP address previously defined as said alias; and

wherein

said program instructions are stored on said computer readable storage media.

6. A computer program product as set forth in claim 5 wherein said one or more routing devices have one or more respective private IP addresses.

7. A computer program product for each of a plurality of load balancers for accessing a cluster of servers wherein one or more routing devices are coupled to a public network, a first private subnet is logically interposed between said one or more routing devices and said plurality of load balancers, and a second private network is logically interposed between said plurality of load balancers and said cluster of servers, said computer program product comprising:

program instructions to define, at an initialization time, a private IP address within the public network for said plurality of load balancers, and in response to one of said load balancers switching from a standby state to an active state, to define said private IP address as an alias in an interface table to be recognized by said one load balancer, and in response to said one load balancer switching from an active state to a standby state, to release from said interface table said private IP address previously defined as said alias; and

wherein

said program instructions are stored on said computer readable storage media.

8. A computer program product as set forth in claim 7 wherein said one or more routing devices have one or more respective private IP addresses.