HP Serviceguard Oracle DataGuard Toolkit User Guide, April 2011

Figure 5 Data Guard replication between RAC primary and RAC standby
Figure 5 (page 11), shows a Data Guard configuration where both primary and standby
databases are configured in two different RAC setups. The RAC primary is configured on
nodes 1 and 2 of SG Cluster 1 and the RAC standby is configured on nodes 1 and 2 of SG
Cluster 2. Note that these two clusters are not a part of a Continentalclusters. Data Guard
replication takes place between the RAC primary and the RAC standby.
In RAC standby, only one standby instance will perform the task of applying the redo logs to
the database. This instance is known as the recovery instance and all other standby instances
will be known as the receiving instances. When the recovery instance fails, the method of
restarting the redo apply depends on whether the Data Guard Broker is configured. If the
Broker is used, the redo apply will restart automatically on the first available standby instance.
If the Broker is not used, the redo apply will have to manually restarted on one of the other
standby instances.
Continentalclusters environment
A Continentalclusters configuration provides an alternative disaster tolerant solution in which two
clusters are geographically dispersed. For information about setting up Continentalclusters, see
the document Designing Disaster Recovery HA Clusters Using Metrocluster and Continentalclusters
Manual available at http://www.hp.com/go/hpux-serviceguard-docs.
A typical Continentalclusters environment consists of a Primary Cluster (SG Cluster 1) and a Recovery
Cluster (SG Cluster 2). In the Primary Cluster, Data Guard is configured using the ODG toolkit
while the Oracle database is placed on a disk that is shared between the nodes in the Primary
Cluster. The standby database is created in the Recovery Cluster and is also placed on a shared
disk. A Recovery group is created in the Continentalclusters environment with the following three
packages:
1. Primary package: This package is created using the ODG toolkit on the Primary Cluster. It
will bring up the Oracle database on the Primary Cluster as a primary database and will start
monitoring the primary database processes. If the primary database fails on Node 1, the
Primary package will be failed over to another node within the Primary Cluster.
2. Data Receiver package: This package is created using the ODG toolkit on the Recovery Cluster.
It will bring the Oracle database on the Recovery Cluster in Standby mode and will start
monitoring the standby database processes. If the standby database fails, this package will
halt the Oracle database and will failover the package to another node within the Recovery
Cluster.
3. Recovery package: This package is also created using the ODG toolkit on the Recovery Cluster.
It will be configured to bring up the Oracle database on the Recovery Cluster in Primary mode.
Supported configurations 11