How VCS Global Clusters Work

Let us take the example of an Oracle database configured in a VCS global cluster. Oracle is installed and configured in both clusters. Oracle data is located on shared disks within each cluster and is replicated across clusters to ensure data concurrency. The Oracle service group is online on a system in cluster A and is configured to fail over globally, on clusters A and B.

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VCS continuously monitors and communicates events between clusters. Inter-cluster communication ensures that the global cluster is aware of the state of global service group at all times.

In the event of a system or application failure, VCS fails over the Oracle service group to another system in the same cluster. If the entire cluster fails, VCS fails over the service group to the remote cluster, which is part of the global cluster. VCS also redirects clients once the application is online on the new location.