Manage instances-PolarDB(PolarDB)-阿里云帮助中心

This topic describes how to manage PolarDB-X 1.0 read-only compute resource instances.

View read-only instances

From the instance list page
On the instance list page, click the ID of a read-only instance to go to its Basic Information page.

Note A read-only instance is identified by the icon next to its instance ID.
From the Basic Information page of a primary instance
1. On the instance list page, click the ID of a primary instance to go to its Basic Information page.
2. In the Related Instances section, move your mouse pointer over the number of read-only instances. The IDs of the read-only instances are displayed.
3. Click an instance ID to go to the Basic Information page of the corresponding read-only instance.

View the database list of a read-only instance

A read-only instance's database is a replica of the primary instance's database. The PolarDB-X 1.0 storage resource instance for the database of the read-only instance and the PolarDB-X 1.0 storage resource instance for the database of the primary instance are the same. To prevent service disruptions on the primary instance, we recommend that you select a PolarDB-X 1.0 read-only storage resource instance for the read-only instance that is not already in use by the primary instance's database.

If a primary instance already has databases, the databases are replicated to the new read-only instance. In the database list of the read-only instance, these databases have a status of Select RDS.

Click Select RDS to open the page where you can select a private custom RDS instance.

Note You cannot create or delete databases from the management interface of a PolarDB-X 1.0 compute resource read-only instance. Databases on a read-only instance are automatically created or deleted when you create or delete them on the primary instance.

Select a private custom RDS instance

Data for a PolarDB-X 1.0 compute resource read-only instance is stored on PolarDB-X 1.0 storage resource instances, including PolarDB-X 1.0 storage resource primary instances and PolarDB-X 1.0 storage resource read-only instances. On the Storage Node Information page, you can view all available PolarDB-X 1.0 storage resource instances for the current database.

The PolarDB-X 1.0 storage resource primary instance in the list is the primary instance used by the database on the corresponding PolarDB-X 1.0 compute resource primary instance. The list is grouped by PolarDB-X 1.0 storage resource primary instance. In the Actions column, click Select to select a PolarDB-X 1.0 storage resource instance for the current PolarDB-X 1.0 compute resource read-only instance.

Note

We recommend that you select a new PolarDB-X 1.0 storage resource read-only instance. Using the same PolarDB-X 1.0 storage resource read-only instance for both a PolarDB-X 1.0 compute resource primary instance and a PolarDB-X 1.0 compute resource read-only instance can affect the service stability of the PolarDB-X 1.0 compute resource primary instance.
PolarDB-X 1.0 primary compute resource instance is scaled out, the corresponding database on the PolarDB-X 1.0 read-only compute instance defaults to using the target Primary instance of the PolarDB-X 1.0 storage resource. You must switch this PolarDB-X 1.0 storage resource primary instance to its corresponding PolarDB-X 1.0 storage resource read-only instance as soon as possible.

Release a read-only instance

You can release a PolarDB-X 1.0 read-only compute instance from the instance list page or its Basic Information page. After a read-only instance is released, the databases on that instance are also deleted. This operation does not affect the databases on the PolarDB-X 1.0 primary compute instance.