Manage read replica scaling

Prerequisites

• A read replica exists in the cluster. For more information, see Add a read replica to a cluster.

• The storage space and resource specification of the cluster meet the scaling requirements. If they do not, you can scale the storage space or resource specification. For more information, see Modify storage space or Modify package specifications.

Procedure

You can go to the Manage Read Replicas page in one of the following ways:

Method 1: Log on to the OceanBase console. In the instance list, find the destination cluster instance and click More in the Actions column.

Method 2: Log on to the OceanBase console. In the instance list, click the name of the destination cluster to go to the Cluster Instance Workspace page. In the upper-right corner of the page, click .

The following steps use Method 1 as an example.

1. Log on to the OceanBase console.

2. In the navigation pane on the left, click Instance List.

3. In the instance list, find the destination cluster instance and click More in the Actions column.

4. Click Manage Read Replicas. On this page, you can add, delete, or scale the storage, resource specification, and nodes of a read replica.

   Parameter	Description
   Add read replica	You can add a new read replica in only one zone at a time. You cannot create read replicas across multiple zones at the same time. Use the same specifications as the original replica. After you configure tenant settings to synchronize data, the read replica is ready for use. For more information, see Add a read replica for a tenant.
   Add read-only column-store replica	After you create a read-only column-store replica for the cluster, you must create a read-only column-store replica for the tenant on the Tenant Management page. Then, create a read-only endpoint to query the read-only column-store replica and execute SQL statements for data analytics. For more information, see Add a read replica for a tenant.
   Delete read replica	This operation deletes all resources of the read replica. Before you proceed, make sure that the tenant no longer needs to access the replica. Delete the read replica of the tenant before you perform this operation. For more information, see Delete a read replica of a tenant.
   Storage scale-out	Scales out the storage of the read replica in the selected zone.
   Storage scale-in	Scales in the storage of the read replica in the selected zone.
   Specification scale-out	Scales out the specifications of the read replica in the selected zone.
   Specification scale-in	Scales in the specifications of the read replica in the selected zone. Note The minimum specifications for an OceanBase cluster instance are 4 cores and 16 GB of memory. Scaling in to smaller specifications is not supported.
   Node scale-out	Adds nodes to the read replica in the selected zone. Note The number of nodes for a read replica in a single zone cannot be greater than the number of nodes for the cluster instance in a single zone.
   Node scale-in	Deletes nodes from the read replica in the selected zone. Note The minimum number of nodes for a read replica in a single zone is 1.

5. Click OK. You are then redirected to the payment page.

6. As needed, set Nodes and Read Replica Storage Size. Then, check Terms of Service and click Purchase.

   Parameter	Description
   Nodes	This includes node specifications and the number of nodes. Click to add a node and select the node specifications from the drop-down list. Before you set the number of nodes and node specifications, note the following: In a single zone, all nodes of a read replica must have the same specifications. Different read replicas can have different node specifications. For easier management, keep the node specifications of read replicas in all zones the same as the cluster specifications. The node specifications of all read replicas must be smaller than the specifications of a single node in the cluster instance. The number of read replica nodes in a single zone cannot exceed the number of cluster nodes in a single zone. For example, if Node Distribution is 2-2-2 on the Cluster Instance Workspace page, the number of read replica nodes that can be created in each zone cannot exceed 2. When you select node specifications for a read replica, if the cluster instance is V4.x, the minimum node specifications are 4 cores. If the cluster instance is V3.x, the minimum node specifications are 8 cores.
   Read Replica Storage Size	The storage size of the read replica, in GB. Note The minimum Read Replica Storage Size cannot be smaller than the minimum storage size allowed by the current specifications.