Brocade Communications Systems ServerIron ADX 12.4.00 Manual Manual page 63

Changing the sample interval weight
The interval weights are the relative weights of each data sample within a set of sampling intervals.
When the data samples are averaged together, the relative weights of the samples can affect the
outcome. You can adjust the load calculation formula by changing the weights of the intervals, so
that some intervals are counted more heavily towards the average than other intervals. You can
even eliminate the effect of an interval by setting its weight to 0.
For example, if a sampling interval contains six data samples and you assign higher weights to the
third and fourth samples than to the others, the third and fourth samples play a larger role when
the average connection load is calculated.
The default weight for each interval is 1. You can individually change the weight to a value from
0-10. If you set an interval's weight to 0, that interval is not included when the intervals are
averaged together.
By default, the site ServerIron ADX weighs each data sample equally when calculating the
connection average for the GSLB policy. The weight of each interval is 1 by default.
You can change the weights to give more emphasis to some intervals and less emphasis to others.
For example, if you are using five intervals, all five have equal influence on the average load
calculated by the GSLB policy. If you want to give more emphasis to the third interval, you can give
the third interval a higher weight than the other intervals. To ignore an interval when calculating the
average, assign the weight 0 (zero) to the interval.
To change sample weights, enter a command such as the following at the GSLB policy level of the
CLI.
ServerIronADX(config-gslb-policy)# connection-load weights 1 1 3 1 1
This command gives more weight to the third sampling interval than to the other intervals, while
including all intervals in the calculation of the average connection load.
Syntax: [no] connection-load weights <weight1> [<weight2>...<weight8>]
The <weight> parameters specify the weights. You can specify from 0-10. If you enter 0, the interval
is not included when calculating the average load. Enter the weights in the same order as the
sampling intervals.
You do not need to enter weight values for all the intervals once you enter the last non-zero weight.
For example, if you want to set the weight for interval three to 1 but use 0 for the weights of all the
other intervals, you can enter the following command.
ServerIronADX(config-gslb-policy)# connection-load weights 0 0 1
When this command is entered, the weights for the fourth interval and higher are set to 0.
Changing the session-table capacity threshold and tolerance values
You can change the following parameters associated with the session-table metrics:
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ServerIron ADX Global Server Load Balancing Guide
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Session capacity threshold: Specifies how close to the maximum session capacity the site
ServerIron ADX (remote ServerIron ADX) 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 ServerIron ADX is eligible to
be the best site only if its session utilization is below 90%.
Available session capacity tolerance: Specifies the percentage by which the number of
available sessions on the site ServerIron ADX can differ from the number of available sessions
on another site ServerIron ADX and still be considered an equally good site.
Configuring GSLB protocol parameters
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