Manage read-only replicas of an instance

This topic describes how to scale the specifications, storage, and node count of read-only replicas of an instance.

Prerequisites

• At least one read-only replica exists in the instance. For more information about how to add a read-only replica to an instance, see Add a read-only replica to an instance.

• The instance has available storage space and specifications resources for scaling. For more information, see Modify the instance configuration.

Procedure

1. Log in to the OceanBase Cloud console.

2. In the left-side navigation pane, click Instances.

3. In the instance list, find the target instance, and choose ··· > Manage Read-Only Replicas in the Actions column.

4. In the Manage Read-Only Replicas dialog box, you can scale the read-only replicas in terms of compute specification, node configuration, etc.

   Parameter	Description
   Create Read-Only Replica	You can only create read-only replicas in one zone at a time. Creating read-only replicas in multiple zones simultaneously is not allowed. We recommend that you use the same specification as the original one. After data synchronization is completed in the tenant settings, the read-only replica can be used normally. For more information, see Add a read-only replica to a tenant.
   Create Read-Only Columnstore Replica	After an instance creates a read-only columnstore replica, you need to create a read-only columnstore replica for the tenant and also create a read-only endpoint to query the read-only columnstore replica for data analysis. For more information, see Add a read-only replica to a tenant.
   Scale up Compute & Storage	Scale up the storage of the read-only replica in the selected zone.
   Scale down Compute & Storage	Scale down the storage of the read-only replica in the selected zone.
   Add Nodes	Add a node to the read-only replica in the selected zone. Note The number of nodes in a single-zone read-only replica cannot exceed the number of nodes in a single zone of the instance.
   Delete Nodes	Delete a node from the read-only replica in the selected zone. Note The minimum number of nodes allowed in a single-zone read-only replica is 1.
   Delete Read-Only Replica	This operation deletes all resources of the read-only replica. Make sure that the tenant no longer needs access to the replica. After you delete a read-only replica of a tenant, you can delete the replica. For more information, see Delete a read-only replica of a tenant.

5. Click OK. You will be directed to the payment page.

6. Configure the nodes and read-only replica storage size, select Service Agreement, and complete the purchase.

   Parameter	Description
   Node	The node specification and quantity. You can add a node and select a node specification from the drop-down list. Before setting the node quantity and specification, note that: All node specifications of the read-only replicas in a zone must be the same, while the specifications of read-only nodes of different read-only replicas can be different. For ease of management, we recommend that you use the same node specifications for read-only replicas in all zones as those of the instance. The number of nodes in a read-only replica in a zone cannot exceed the node number of the instance in the same zone. For example, if the node distribution of the instance is 2-2-2, the maximum number of nodes that can be created for a read-only replica in each zone is 2. For the selection of read-only replica node specifications, if its instance version is V4.x, the minimum node specification supports 4 cores. If its instance version is V3.x, the minimum node specification supports 8 cores.
   Read-Only Replica Storage	The storage size of a read-only replica in GiBs. Note The minimum storage size of the read-only replica cannot be less than the minimum storage size required by the current specifications.