Add a replica

This topic describes how to add a tenant replica.

Precautions

In a standalone centralized database, you cannot add replicas for a tenant.

Procedure

1. Log on to the OceanBase Cloud Platform (OCP) console.

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

3. In the Tenants section, select the target tenant to go to its Overview page.

4. Click Create Replica in the upper-right corner of the page.

   

5. In the dialog box that appears, configure the Target Zone, Replica Type, Unit Specifications, and Units parameters. You can add replicas for multiple zones.

   

   Parameter	Description
   Target Zone	The zone where the new replica exists. You can select a zone of the current cluster.
   Replica Type	Valid values: Full-featured Replica, Read-only Replica, and Log Replica. Full-featured Replica: A standard replica that provides complete data and features, including transaction logs, a MemTable, and an SSTable. A full-featured replica can switch to the leader role efficiently to provide services. Read-only Replica: A replica that contains full logs, MemTables, and SSTables. It does not participate in log voting as a member of the Paxos group. Instead, it works as an observer that synchronizes logs from the Paxos group members and then locally replays the logs. Log Replica: A replica that contains only logs. It does not have a MemTable or an SSTable. It provides log services for external applications and participates in log voting. It can facilitate the recovery of other replicas, but it cannot become the leader to provide database services. Note If the cluster version is OceanBase Database V4.0.0 or later but earlier than V4.2.0, only full-featured replicas are supported. A cluster of OceanBase Database V4.2.0 or later supports full-featured and read-only replicas.
   Unit Specification	The unit specifications for the new replica. Note If the cluster version is OceanBase Database V4.0.0 or later, the unit specifications are limited by default. If you want to use specifications lower than the default specifications, you can modify the __min_full_resource_pool_memory parameter to adjust the minimum values for the unit specifications. For example, if your cluster version is OceanBase Database V4.1.0, you can modify the parameter by referring to the Modify cluster parameters topic.
   Units	The number of units for the new replica. Note If the cluster is of OceanBase Database V4.0 or later, you can specify only the same number of units for all zones. When you create the first replica of a tenant, the number of units that you specify in this dialog box applies to all zones under this tenant. If the tenant already has a replica, you can no longer set the number of units for the new replica. By default, the number of units for the new replica is the same as that for the first created replica.

6. Click OK.