Reference Guide

48 Understanding Your Failover Cluster
Failover Policies
When implementing a failover policy, configure failback if the cluster node
lacks the resources (such as memory or processing power) to support cluster
node failures.
Windows Server 2003 Cluster Configurations
Cluster configurations running Windows Server 2003 provide the following
failover policies:
• N (number of active nodes)+ I (number of inactive nodes) failover
• Failover pair
• Multiway failover
• Failover ring
Table 4-7 provides an overview of the failover policies implemented with
Windows Server 2003. For more information, see the sections that follow this
table.
Table 4-7. Windows Server 2003 Failover Policies
Failover
Policy
Description Advantage Disadvantage(s)
N + I One or more nodes
provides backup for
multiple servers.
Highest
resource
availability.
• May not handle more than
one backup node failure.
• May not fully utilize all of
the nodes.
Failover pair Applications can fail
over between the two
nodes.
Easy to plan the
capacity of each
node.
Applications on the pair
cannot tolerate two node
failures.
Multiway Running applications
migrate to multiple
nodes in the cluster.
Application load
balancing.
Must ensure that the
failover nodes have ample
resources available to handle
the additional workload.
Failover ring Running applications
migrate to the next
preassigned node.
Easy to scope
node capacity
for one server
failure.
The next node for failover
may not have ample
resources to handle the
workload.