Brocade Virtual ADX Server Load Balancing Guide (Supporting ADX v03.1.00) - Manual (Page 39)

Brocade Virtual ADX Server Load Balancing Guide 23
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Changing the Load-Balancing Predictor Method
2
Assigning weights to the real servers
When configuring Weights on a real server, consider the following:
• Real Server Weight assignments apply to all ports configured under the real server.
• For the Weighted Round Robin predictor, server weights are assigned at the server level and
not at the server port level. The load balancing, however, is based on per-server port.
• The Weighted Round Robin predictor has VIP port-level granularity. This granularity is reflected
in the output from the show server session and show server conn commands, because they
display output for the Weighted Round Robin predictor at a per vip-port level.
To configure weights for three real servers, enter commands such as the following.
Virtual ADX(config)#server real rsA
Virtual ADX(config-rs-rsA)#weight 1
Virtual ADX(config-rs-rsA)#exit
Virtual ADX(config)#server real rsB
Virtual ADX(config-rs-rsB)#weight 2
Virtual ADX(config-rs-rsB)#exit
Virtual ADX(config)#server real rsC
Virtual ADX(config-rs-rsC)#weight 3
Virtual ADX(config-rs-rsC)#exit
Syntax: [no] weight weight-value
The weight command assigns a performance weight to each server or firewall. Servers or firewalls
with a larger or higher weight assigned receive a larger percentage of connections.
The weight-value variable specifies the real server’s weight relative to other real servers in terms of
the number of connections on the server. More precisely, this weight is based on the number of
session table entries the Brocade Virtual ADX has for TCP or UDP sessions with the real server. You
can specify a value from 0 through 65000. The default is 1.
Configuring the weight for real servers
This weight command specifies the weight assigned to the real server. It is used for the weighted
and least connection with server response-time-weights for load balancing methods.
Suppose you want to assign a higher weight to real server Web1 to bias traffic toward that server.
No other changes are made to the weights of Web servers 2, 3, and 4, and they remain configured
with the default weight of zero (
Figure 5 ). Enter commands such as the following.
Virtual ADX(config)#server virtual-name-or-ip www.example7.com
Virtual ADX(config-vs-www.example7.com)#predictor weighted
Virtual ADX(config-vs-www.example7.com)#server real Web1 10.95.55.21
Virtual ADX(config-vs-www.example7.com)#exit
Virtual ADX(config)#server real Web1
Virtual ADX(config-rs-Web1)#weight 10
Syntax: weight least-connections-weight
The least-connections-weight variable specifies the real server’s weight relative to other real
servers in terms of the number of connections on the server. More precisely, this weight is based
on the number of session table entries the Brocade Virtual ADX has for TCP or UDP sessions with
the real server. You can specify a value from 0 to 65000. The default is 1. However, if you want to
use a weight value only for the Server Response Time but not for the number of connections,
specify 0 for this variable.