Global server load balancing

摘要

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.

主权项

1. A method of providing load balancing, the method comprising:
determining, by a first network device to load balance, from at least one report provided to the first network device by at least one second network device, a number of active host servers bound to each of a plurality of virtual addresses, wherein the report comprises information corresponding to a configuration of one or more virtual ports for each of the virtual addresses and a number of active real servers bound to the one or more virtual ports; receiving, by the first network device, a list of virtual addresses; and arranging, by the first network device based on the at least one report provided to the first network device by a second network device, the virtual addresses in the list of virtual addresses to identify at least one virtual address, having a highest determined number of active host servers bound to it, from the list as a candidate optimum virtual address to receive traffic, wherein the first network device is configurable as a proxy to an authoritative domain name system (DNS) server that resolves a name into the addresses in the list.