Compaq ProLiant Clusters HA/F100 Administrator's Manual page 39

Designing the Compaq ProLiant Clusters HA/F100 and HA/F200 2-5
Example 2: Database/Database
Another scenario (Figure 2-2) has two distinct database applications running
on two separate cluster nodes. One database application maintains Human
Resources records, and its primary node is set to the HR database node. The
other database application is used for market research, and its primary node is
set to the Marketing database node.
Order Entry Order Entry
Database Database
Shared Storage
Node 1 Node 2
(Order Entry) (Order Entry)
Figure 2-2. Active/active example 2
While in a normal state, both cluster nodes run at expected performance levels.
If the Marketing server encounters a failure, the market research application
and associated data resources fail over to their secondary node, the HR
database server. The Marketing clients experience a slight disruption of
service while the database resources are failed over, the database transaction
log is rolled back, and the information in the database is validated. When the
database validation is complete, the market research application is brought
online on the HR database node and the Marketing clients can reconnect to it.
While the Marketing database validation is occurring, the HR clients do not
experience any disruption of service.