Weighted Round Robin Distribution Algorithm - Alcatel-Lucent OmniSwitch 6850-48 Network Configuration Manual

Configuring Server Load Balancing

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 (i.e., "in service") depending on some criteria. This
method is commonly called the SLB cluster's 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 will handle 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).
Server A
IP: 128.241.130.107
Loopback Address:
128.241.130.204
Note. See "Modifying the Relative Weight of a Physical Server" on page 44-29
modifying the relative weights of servers in an SLB cluster.
OmniSwitch AOS Release 6 Network Configuration Guide
SLB CLuster "WorldWideWeb"
VIP: 128.241.130.204
Server B Server C
IP: 128.241.130.109 IP: 128.241.130.115
Loopback Address: Loopback Address:
128.241.130.204
OmniSwitch 7800
Switch
Weighted Round Robin Algorithm
September 2009
Server Load Balancing Overview
Server D
IP: 128.241.130.135
Loopback Address:
128.241.130.204 128.241.130.204
Server A handles twice the traffic of Server C,
three times the traffic of Server D, and six
times the traffic of Server B.
for information on
page 44-9