CONTINENTAL_CLUSTER_STATE_DIR /opt/cmconcl/statedir
2.Under the recovery group section for which the rehearsal package was configured, enter the rehearsal package name against REHEARSAL_PACKAGE field.
For Example:
Recovery group inv_rac10g_recgp
Primary package | Atlanta/inv_rac10g_primpkg |
Recovery package | Houston/inv_rac10g_recpkg |
Rehearsal package | Houston/inv_rac10g_rhpkg |
3.Halt the monitor package.
#cmhaltpkg ccmonpkg
4.Verify the Continentalclusters configuration ASCII file.
#cmcheckconcl -v -C cmconcl.config
5.Apply the Continentalclusters configuration file.
#cmapplyconcl -v -C cmconcl.config
6.Start the monitor package.
#cmrunpkg ccmonpkg
Precautions to be taken while performing DR Rehearsal
This section describes the precautions that the operator must follow while performing DR rehearsals.
Client access IP address at recovery cluster
During a DR rehearsal, Continentalclusters will start the rehearsal package that is configured to bring up the application instance at the recovery cluster. After the application instance starts at the recovery cluster, clients must presume that a recovery has occurred, and must attempt to connect to it to perform production transactions. This can lead to split brain situation, where one set of clients are connected to the application instance at the primary cluster while the second set of clients are connected to the application instance at the recovery cluster (which was started for rehearsal). Hence, during rehearsal, it is the operator’s responsibility to ensure that production clients do not access the application instance at the recovery cluster and attempt production transactions.
One way to prevent split brain is to prevent application access to clients, which can be done by modifying the client access IP address at the recovery cluster during rehearsal. For example, when rehearsal package is configured for Oracle Single Instance, ensure that the rehearsal package IP address is different from that of the recovery package.
Cluster role switch during rehearsal
Using the Continentalclusters commands cmswitchconcl and cmapplyconcl, the recovery cluster role can be changed to be the new primary cluster. Operators are responsible for ensuring that the recovery groups are not in maintenance mode before attempting to switch cluster roles.
This can potentially allow primary packages to start on disks invalidated by the rehearsal at the new primary cluster.
Performing Disaster Recovery rehearsal in Continentalclusters
To start and stop rehearsal for a recovery group:
1.Verify the data replication environment.
2.Move the recovery group into maintenance mode.
3.Prepare the replication environment for DR rehearsal.
4.Start the rehearsal for the recovery group.
5.Stop the rehearsal package.
Precautions to be taken while performing DR Rehearsal 39
