Brocade Communications Systems 12.4.00 Manual De Usuario
ServerIron ADX Global Server Load Balancing Guide
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Round-trip times
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Syntax: [no] gslb active-rtt-gathering
Once you enter this command on the GSLB ServerIron ADX, the GSLB ServerIron ADX performs a
message exchange with each Site ServerIron ADX to determine if it is running a version that
supports active RTT gathering. If it does, then the GSLB ServerIron ADX instructs the Site ServerIron
ADX to enable active RTT gathering.
message exchange with each Site ServerIron ADX to determine if it is running a version that
supports active RTT gathering. If it does, then the GSLB ServerIron ADX instructs the Site ServerIron
ADX to enable active RTT gathering.
For a new deployment, it is generally helpful to start with minimum values for all active RTT
parameters and a high value for active RTT cache interval. For example, you can configure the
following on all active RTT controllers and Site ServerIron ADXs.
parameters and a high value for active RTT cache interval. For example, you can configure the
following on all active RTT controllers and Site ServerIron ADXs.
...
gslb active-rtt-query-interval 30
gslb agent-active-cache-interval 1800
gslb active-rtt-to-peer-interval 5
gslb agent-rtt-refresh-interval 30
...
Once you determine the active RTT is working correctly for the topology, you can experiment to
determine the best values for that particular network/traffic.
determine the best values for that particular network/traffic.
Discarding passive RTT
Some of the Site ServerIron ADXs for a GSLB ServerIron ADX that has active RTT gathering enabled,
may not support active RTT gathering. These Site ServerIron ADXs report passively gathered RTT to
the GSLB ServerIron ADX. If you do not want the GSLB ServerIron ADX to process any passively
gathered RTT, enter the following command on the GSLB ServerIron ADX.
may not support active RTT gathering. These Site ServerIron ADXs report passively gathered RTT to
the GSLB ServerIron ADX. If you do not want the GSLB ServerIron ADX to process any passively
gathered RTT, enter the following command on the GSLB ServerIron ADX.
GSLB-ServerIronADX# configure terminal
GSLB-ServerIronADX(config)# gslb discard-passive-rtt
Syntax: [no] gslb discard-passive-rtt
Disabling passive RTT gathering
Once the GSLB instructs Site ServerIron ADXs to enable active RTT gathering, Site ServerIron ADXs
use both active and passive methods to gather RTT values. Using the two methods allows a Site
ServerIron ADX to communicate simultaneously with a GSLB ServerIron ADX that has active RTT
enabled and another GSLB ServerIron ADX that does not have active RTT gathering enabled (for
example, ServerIron ADX). The actively gathered RTT value is reported only to GSLB ServerIron ADX
that supports active RTT gathering. The passively gathered RTT is reported only to GSLB ServerIron
ADX that supports passive RTT gathering.
use both active and passive methods to gather RTT values. Using the two methods allows a Site
ServerIron ADX to communicate simultaneously with a GSLB ServerIron ADX that has active RTT
enabled and another GSLB ServerIron ADX that does not have active RTT gathering enabled (for
example, ServerIron ADX). The actively gathered RTT value is reported only to GSLB ServerIron ADX
that supports active RTT gathering. The passively gathered RTT is reported only to GSLB ServerIron
ADX that supports passive RTT gathering.
However, if all the GSLB ServerIron ADXs to which the Site ServerIron ADX is communicating with
support active RTT gathering, then you can disable passive RTT gathering on the Site ServerIron
ADXs by entering the following command.
support active RTT gathering, then you can disable passive RTT gathering on the Site ServerIron
ADXs by entering the following command.
SITE-ServerIronADX# configure terminal
SITE-ServerIronADX(config)# gslb disable-rtt-gathering
Syntax: [no] gslb disable-rtt-gathering