How to Perform a Failback Switchover on a System That
Uses Oracle Data Guard Replication
Follow this procedure to restart an application on the original primary cluster, cluster-paris, after the data on the cluster has been resynchronized with the data on the current primary cluster, cluster-newyork.
The failback procedures apply only to clusters in a partnership. You need to perform the following procedure only once for each partnership.
Before You Begin
Before you perform a failback switchover, a takeover has occurred on cluster-newyork. The clusters now have the following roles:
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The protection group on cluster-newyork is assigned the primary role.
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The protection group on cluster-paris has either the primary role or the secondary role, depending on whether the cluster-paris cluster could be reached during the takeover from the cluster-newyork cluster.
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If the original primary cluster, cluster-paris, failed, confirm that the cluster is restarted and that the Sun Cluster Geographic Edition infrastructure is enabled on the cluster.
For more information about restarting a cluster, see Booting a Cluster in Sun Cluster Geographic Edition System Administration Guide.
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Recover and restore the failed Oracle Data Guard primary database as the new standby.
Refer to the Oracle documentation, which describes how to perform this step.
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Ensure that the original primary cluster, cluster-paris, is working correctly as part of the Oracle Data Guard configuration.
oracle (phys-paris-1)$ dgmgrl sys/sysdba_password@sales-svc DGMGRL> show configuration;
If the original primary cluster, cluster-paris, is working correctly, the show configuration command displays the SUCCESS state.
If the original primary cluster was down at the point of failure, it is marked as a deactivated primary cluster. If the original primary cluster was up at the point of failure, it is marked as a deactivated secondary.
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Resynchronize the original primary cluster, cluster-paris, with the current primary cluster cluster-newyork.
The cluster cluster-paris forfeits its own configuration and replicates the cluster-newyork configuration locally. Resynchronize both the partnership and protection group configurations.
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On cluster-paris, resynchronize the partnership.
phys-paris-1# geops update partnershipname
Note –You need to perform this step only once for each partnership, even if you are performing a failback switchover for multiple protection groups in the partnership.
For more information about synchronizing partnerships, see Resynchronizing a Partnership in Sun Cluster Geographic Edition System Administration Guide.
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Determine whether the protection group on the original primary cluster, cluster-paris, is active.
phys-paris-1# geoadm status
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If the protection group on the original primary cluster is active, stop the protection group.
phys-paris-1# geopg stop -e local protectiongroupname
- -e local
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Specifies the scope of the command.
By specifying a local scope, the command operates on the local cluster only.
Note –The property values, such as global and local, are not case sensitive.
- protectiongroupname
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Specifies the name of the protection group.
If the protection group is already deactivated, the state of the resource group in the protection group is probably Error because the application resource groups are managed and offline.
If you deactivate the protection group, the application resource groups are no longer managed, clearing the Error state.
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Verify that the protection group is stopped.
phys-paris-1# geoadm status
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On cluster-paris, resynchronize each protection group.
Because the local role of the protection group on the cluster-newyork cluster is now primary, this step ensures that the role of the protection group on the cluster-paris cluster becomes secondary.
phys-paris-1# geopg update protectiongroupname
For more information about synchronizing protection groups, see Resynchronizing an Oracle Data Guard Protection Group.
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On cluster-paris, validate the configuration for each protection group.
A protection group cannot be started when it is in an Error state. Ensure that the protection group is not in an Error state.
phys-paris-1# geopg validate protectiongroupname
For more information, see How to Validate an Oracle Data Guard Protection Group.
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On cluster-paris, activate each protection group.
When you activate a protection group, its application resource groups are also brought online.
phys-paris-1# geopg start -e global protectiongroupname
- -e global
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Specifies the scope of the command.
By specifying a global scope, the command operates on both clusters where the protection group is located.
Note –The property values, such as global and local, are not case sensitive.
- protectiongroupname
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Specifies the name of the protection group.
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Confirm that the data is completely synchronized.
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Confirm that the state of the protection group on cluster-newyork is OK.
phys-newyork-1# geoadm status
Refer to the Protection Group section of the output.
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Confirm that all resources in the replication resource group, ODGprotectiongroupname-odg-rep-rg, report a status of OK.
phys-newyork-1# clresource status -v ODGprotectiongroupname-odg-rep-rs
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On both partner clusters, ensure that the protection group is activated.
phys-paris-1# geoadm status … phys-newyork-1# geoadm status …
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For each protection group, on either cluster, perform a switchover from cluster-newyork to cluster-paris.
phys-node-n# geopg switchover [-f] -m cluster-paris protectiongroupname
For more information, see How to Switch Over an Oracle Data Guard Protection Group From the Primary to the Standby Cluster.
The cluster-paris cluster resumes its original role as primary cluster for the protection group.
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Ensure that the switchover was performed successfully.
phys-node-n# geoadm status
Verify that the protection group is now primary on cluster-paris and secondary on cluster-newyork and that the states that are shown for the Data replication and the Resource groups properties are OK on both clusters.
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Check the runtime status of the application resource group and data replication for each Oracle Data Guard protection group.
phys-node-n# clresourcegroup status -v resourcegroupname # clresource status -v ODGConfigurationName-odg-rep-rs
Refer to the Status and Status Message fields that are presented for the Oracle Data Guard Broker configuration that you want to check. For more information about these fields, see Table 2–1.
For more information about the runtime status of data replication, see Checking the Runtime Status of Oracle Data Guard Data Replication.
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