HP Serviceguard Toolkits for Database Replication Solutions User Guide, March 2012

fails, the Serviceguard configured on the primary cluster fails over the database to another node
within the primary cluster, thus providing high availability to the primary database. Similarly, if
the standby database fails, then the Serviceguard configured on the recovery cluster allows the
database to failover to another node within the recovery cluster. When the primary cluster is down,
the administrator must run the cmrecovercl command on the recovery cluster to bring up the
recovery package. This command halts the Data Receiver package, which in turn halts the standby
database. It then runs the recovery package, which brings up the database as a primary database
by performing a role failover. In this case, ODG toolkit handles role management. The start up
time of a recovery package is usually double than the start up time for an ordinary database
package. This is because the recovery package runs role transition commands which involves
shutting down the database after the role is changed and restarting the database. Hence,
start_script_timeout parameter in the package configuration should be specified
appropriately.
Restoring the cluster in a Continentalclusters to its original state is a manual process. The following
steps must be performed to restore the clusters to their original state:
1. Halt the recovery package — stops the database and the recovery package
2. Resync primary database from the standby database.
3. Start the primary package— brings up the database on primary cluster as a primary database
4. Start the Data Receiver package— brings up the database on the recovery cluster as a standby
database
RAC Environment
Figure 7 RAC environment
In an RAC environment, Figure 7 (page 13), all the three packages (Primary, Data Receiver and
Recovery Packages) are configured as Multi-Node packages (MNPs).
When the primary cluster is down, the recovery package on the recovery cluster must be brought
up by manually running the cmrecovercl command. This command halts the Data Receiver
package, which in turn halts the standby database. It then runs the recovery package, which brings
up the database as a primary database by doing a role failover. In an RAC environment, the start
up time of recovery package is more than that in a single-instance environment, since the role
transition is differently performed. In an RAC environment, during role failover only one of the
standby database instances (say, Instance A) should be running while others should be shutdown.
These other instances wait for Instance A to perform role failover, shutdown, and then restart. Once
these operations are performed on Instance A, the other instances are started. Hence
Supported configuration 13