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Intel NetStructure Cache Appliance Administrator’s Guide
Setting Web management options
The Web Management section lets you restart the cluster and specify refresh rates
as observed in monitor mode. The following table describes these configuration
settings.
Setting virtual IP addressing options
The Virtual IP Addressing section lets you define and maintain the appliance’s
pool of virtual IP addresses.
The appliance keeps a pool of IP addresses as virtual IP addresses from which to
draw and assign IP addresses to nodes as necessary. This practice assures that if a
node in the cluster fails, other nodes can assume the failed node’s responsibilities.
What are virtual IP addresses?
Virtual IP addresses are really just IP addresses. They are called virtual addresses
because they are not tethered to particular machines and can rotate among nodes
in a cluster.
It is common for a single machine to represent multiple IP addresses on the same
subnet. This machine would have a primary or real IP address bound to its
interface card and would also serve many more virtual addresses.
Using virtual IP addressing for node failover
You can set up your user base to use a DNS round-robin pointing at virtual IP
addresses, as opposed to using the real IP addresses of the appliance machines in
the cluster.
Because virtual IP addresses are not bound to machines, a cluster can steal
addresses from inactive nodes and distribute those addresses among the
remaining live nodes.
Using a proprietary management protocol, appliance nodes communicate their
status with their peers. If a node fails, its peers notice the failure and quickly
negotiate which of the remaining nodes will mask the fault by taking over the
failed node’s virtual interface.
Option
Description
Restart
Restarts the entire cluster.
You must restart the cluster to effect changes you have
made to port numbers and virtual IP addresses on the
selected node. Restarting the cluster takes about 15
seconds, during which time cache and proxy services
are disabled.
Refresh rate in
Monitor mode
Specifies the refresh rate for the display of the graphs
and statistics with which you can monitor the appliance’s
performance.
