146 Intel NetStructure Cache Appliance Administrator’s Guide
Figure 10 The Monitor Dashboard
The appliance also supports email notification for alarms. You set the email
address to which alarms are sent from the command-line interface.
Virtual IP failover
The virtual IP failover option is available to clustered Intel NetStructure Cache
Appliances. When virtual IP failover is enabled, the appliance maintains a pool of
virtual IP addresses that it assigns to the nodes in the cluster. These addresses are
virtual only in the sense that they are not tied to a specific machine; the appliance
has the flexibility to assign them to any node in the cluster. To the outside world,
these virtual IP addresses are the addresses of the appliance cluster.
The appliance handles virtual IP failover in the following ways:
✔By maintaining cluster communication. Nodes automatically exchange
statistics and configuration information through multicast communication. If
multicast heartbeats are not received from one of the cluster nodes, the other
nodes recognize it as unavailable.
✔By reassigning IP addresses of failed nodes to operational nodes within
approximately 30 seconds. This feature allows service to continue without
interruption.
✔By using the ARP rebinding process to handle IP reassignment. With this
process, the IP addresses are assigned to new network interfaces, and the new
assignment is broadcast to the local network.
You assign virtual IP addresses through the Manager UI as described in Setting
virtual IP addressing options‚ on page 26. Note that virtual IP addresses must be
pre-reserved like all IP addresses, before they can be assigned to an appliance.