Instruction manual

Chapter 3: High Availability
NetScaler 9000 Series Installation and Configuration Guide - Volume 1 3-17
NSICG60_JAN05
3.7.3 Enabling and Disabling Synchronization
To ensure that the Secondary node does not synchronize its configuration
with that on Primary node whenever there is a change in the Primary, use the
following CLI command:
set ns node –hasync DISABLE
To enable synchronization again, use the following command:
set ns node –hasync ENABLE
3.8 Forcing the Secondary Device to Stay
Secondary
In an HA setup, the Secondary node can be forced to stay as a secondary
device independent of the state of the Primary device. For example, in an
existing HA setup, the Primary node has to be upgraded and this process
would take few seconds. During the upgrade, it is possible that the Primary
node may suffer from a downtime for a few seconds. However, the Secondary
should not take over as the Primary node. Thus, the Secondary node should
remain as Secondary even if there is a failure in the Primary node.
The following is the CLI command to set the Secondary mode independent of
the other unit in the HA setup:
set ns node –hastatus STAYSECONDARY
The unit on which this command is issued will remain as Secondary even if
the Primary fails for some reason. If the
-hastatus of a unit is made stay
secondary, this device does not participate in HA State Machine transactions.
The
show node CLI command will display the status of this node as “HA
SUSPENDED”.
The
set ns node –hastatus STAYSECONDARY CLI command works on
a standalone node and a Secondary node. In a standalone node, this command
has to be executed before running the
add node CLI command. When a new
node is added, the existing node will stop processing traffic and functions as
the Secondary node.
Note: If the set ns node –hastatus STAYSECONDARY CLI command
is executed on a secondary node, it will not become the Primary node
even if there is a failure in the Primary node.