Brocade Virtual ADX Global Server Load Balancing Guide (Supporting ADX v03.1.00) - Manual (Page 159)

Brocade Virtual ADX Global Server Load Balancing Guide 149
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Advanced GSLB configuration for IPv6
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If you consider the total site traffic for both applications, the traffic distribution is as follows: San
Jose = 5 (33%); New York = 6 (40%); and London = 4 (26%). The GSLB Brocade Virtual ADX
evaluates the results of the weighted metrics with respect to a specific domain name, not an IP
address alone.
Configuring weighted site metrics
To configure weighted site metrics, complete the following tasks:
1. Enable the weighted site metric.
2. .Select the site for which to apply weights.
3. Configure a weight for the site.
For example, enter commands such as the following:
Virtual ADX(config-gslb-policy)#weighted-site
Virtual ADX(config-gslb-policy)#gslb site SanJose
Virtual ADX(config-gslb-site-SanJose)#weight 50
Syntax: [no] weighted-site
Syntax: gslb site site-name
The site-name can have a maximum of 16 characters.
Syntax: weight weight
The weight is a value from 0 to 100. The default value is 0.
To view the results of traffic distribution after configuring weighted site metrics, use the show gslob
traffic site command. For more information, refer to
“Displaying results of traffic distribution for
weighted sites” on page 167.
Session capacity threshold metric
The GSLB protocol supplies statistics for the session tables on each site ADX device. The session
table contains an entry for each open TCP or UDP session on the site ADX device. Each Brocade
Virtual ADX has a maximum number of sessions that it can hold in its session table. Through the
GSLB protocol, the GSLB Brocade Virtual ADX learns from each remote ADX device the maximum
number of sessions and the number of available sessions on that ADX device.
The capacity threshold specifies how close to the maximum session capacity the site ADX device
(remote ADX device) can be and still be eligible as the best site for the client. This mechanism
provides a way to shift load away from a site before the site becomes congested.
The default value for the threshold is 90%. Thus a site ADX device is eligible to be the best site only
if its session utilization is below 90%. Refer to
“Displaying DNS zone and hosts” on page 169. for
commands to display a site’s utilization and the capacity threshold.