Designing Disaster Tolerant High Availability Clusters, 10th Edition, March 2003 (B7660-90013)

Building a Continental Cluster
Understanding Continental Cluster Concepts
Chapter 5190
Network Attributes
Another important difference between the packages in a continental
cluster and the packages configured in a standard ServiceGuard cluster
is that different subnets are used in recovery packages than the subnets
in the primary packages. The client application must be designed to
reconnect to the appropriate IP address following a recovery operation.
How MC/ServiceGuard commands work in a
ContinentalCluster
ContinentalClusters packages are manipulated manually by the user via
ServiceGuard commands and by cmcld automatically in the same way as
any other packages.
In a continental cluster the recovery package are not allowed to run at
the same time as the primary, data sender, or data receiver packages. To
enforce this, several MC/ServiceGuard commands behave in a slightly
different manner when used in a continental cluster.
Table 5-2 describes the ServiceGuard commands whose behavior is
different in a continental cluster environment. Specifically, when one of
the following commands attempts to start or enable switching of a
package, it first checks the status of the other packages in the recovery
group. Based on this status, the operation is either allowed or
disallowed.