GLOBAL SERVER LOAD BALANCING

• US 20100153558A1
• Filed: 12/10/2009
• Published: 06/17/2010
• Est. Priority Date: 09/26/2000
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Foundry Networks Incorporated (Broadcom, Inc.)
• Inventors: Kommula, Sunanda L.
• Granted Patent: US 9,015,323 B2
• Time in Patent Office: Days
• US Class Current: 709/226
• CPC Class Codes: H04L 61/4511 using domain name system [DNS]
• CPC Class Codes: H04L 67/1001 for accessing one among a plurality of replicated servers
• 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 67/1012 based on compliance of requirements or conditions with available server resources
• CPC Class Codes: H04L 67/1021 based on client or server locations

Abstract

A global server load-balancing (GSLB) switch serves as a proxy to an authoritative DNS and communicates with numerous site switches that are coupled to host servers serving specific applications. The GSLB switch receives from site switches operational information regarding host servers within the site switches neighborhood. When a client program requests a resolution of a host name, the GSLB switch, acting as a proxy of an authoritative DNS, returns one or more ordered IP addresses for the host name. The IP addresses are ordered using metrics that include the information collected from the site switches or based on other metric information. Examples of metrics include weighted site, weighted IP, and active bindings metrics. The GSLB switch places the address that is deemed “best” at the top of the list.

Claims

1. A method of providing load balancing, the method comprising:

determining a number of active host servers bound to each of a plurality of virtual addresses;

receiving a list of virtual addresses; and

arranging the virtual addresses in the list of virtual addresses to identify at least one virtual address, having a highest said determined number of active host servers bound to it, from the list as a candidate optimum virtual address to receive traffic.

2. An apparatus, comprising:

a load balance switch having a controller to arrange a list of addresses and to identify a candidate optimum address as one of said addresses having a largest number of active servers bound to it.