Oracle Cloud Infrastructure Documentation

Creating a Secondary Cluster

Create a secondary cluster to replicate data asynchronously from a primary cluster in another OCI region. The secondary cluster accepts read operations but does not accept write operations while it is in a cross-region replication relationship.

You create a secondary cluster as part of the standard cluster creation workflow. On the Creation type page, select Secondary cluster, and then select the region, compartment, and standalone cluster to use as the primary cluster.

When you create a secondary cluster:

  • The primary cluster must be in another OCI region.
  • The primary cluster must have the standalone role.
  • Only eligible non-sharded clusters are available for selection.
  • The engine version, cluster mode, and memory per node are set to match the primary cluster.
  • The secondary cluster can have a different node count from the primary cluster.
  • OCI Cache configurations and ACL users are not copied from the primary cluster. See Considerations for Cross-Region Replication.
  • OCI Cache manages the private cross-region connectivity used for replication.

For detailed steps to create a secondary cluster, see Creating an OCI Cache Cluster.

Before you create the secondary cluster, ensure that the primary cluster:
  • Is in the Active state.
  • Has the Standalone role.
  • Is not already associated with a secondary cluster.
  • Does not have another operation in progress.
  • Both clusters must use custom OCI Cache configuration sets that meet the cross-region replication requirements. The configuration sets must use the same values for the reserved-memory-percentage and maxmemory-policy parameters. If you set databases to a value other than the default of 16, you must use the same value in both configuration sets. The reserved-memory-percentage must be at least 35, and maxmemory-policy must not be set to noeviction. See Supported Configurations for OCI Cache.