Configuring Server Load Balancing
Server Load Balancing Overview
OmniSwitch AOS Release 7 Network Configuration Guide
June 2013
page 23-9
Weighted Round Robin
Distribution Algorithm
In order to distribute traffic among operating servers, the SLB cluster must have a method of selecting a
server among a pool (cluster) of operating servers (“in service” mode) depending on some criteria. This
method is commonly called the SLB cluster
distribution algorithm.
The distribution algorithm on an Alcatel-Lucent switch is weighted round robin, where the SLB cluster
distributes traffic according to the relative “weight” a server has within an SLB cluster. In the figure
below, for example, Server A has been assigned by the network administrator a relative weight of 30,
which is the largest weight in the SLB cluster called “WorldWideWeb.” Server A handles twice as much
traffic as Server C (which has a weight of 15), three times the traffic of Server D (which has a weight of
10), and six times the traffic of Server B (which has a weight of 5).
Weighted Round Robin Algorithm
Note.
“Modifying the Relative Weight of a Physical Server” on page 23-16
modifying the relative weights of servers in an SLB cluster.
OmniSwitch 7800
SLB CLuster “WorldWideWeb”
VIP: 128.241.130.204
Switch
Server A handles twice the traffic of Server C,
three times the traffic of Server D, and six
times the traffic of Server B.
Server A
IP: 128.241.130.107
Loopback Address:
128.241.130.204
Server B
IP: 128.241.130.109
Loopback Address:
128.241.130.204
Server C
IP: 128.241.130.115
Loopback Address:
128.241.130.204
Server D
IP: 128.241.130.135
Loopback Address:
128.241.130.204