This topic describes how to change the specifications of an ApsaraDB RDS for SQL Server instance. These specifications include the RDS edition, instance type, storage capacity, storage type, and zone.

Prerequisites

Your Alibaba Cloud account does not have overdue renewal orders.

Note You cannot directly upgrade an RDS instance from a shared instance type to a general-purpose or dedicated instance type. This feature is in development. You can create an RDS instance that uses a specific general-purpose or dedicated instance type. Then, you can use Alibaba Cloud Data Transmission Service (DTS) to migrate data to the new RDS instance. For more information, see Data migration solutions.

Change items

You can create read-only RDS instances to increase the read capability of your database system. The read-only RDS instances can offload queries from the primary RDS instance. For more information, see Overview of read-only ApsaraDB RDS for SQL Server instances and Create a read-only ApsaraDB RDS for SQL Server instance.
Change item Description
Database engine version The database engine versions of specific RDS instances can be upgraded to later versions. For more information, see the following topics:
RDS edition You can upgrade the edition of an RDS instance from Basic Edition to High-availability Edition. For more information, see Upgrade an ApsaraDB RDS for SQL Server instance from Basic Edition to High-availability Edition.
Instance type You can change the instance types of all RDS instances.
Storage type
  • You can upgrade the storage type of an RDS instance from standard SSD to enhanced SSD (ESSD). This upgrade is supported only for RDS instances that run SQL Server 2012 or 2016 on RDS High-availability Edition. You cannot downgrade the storage type of an RDS instance from ESSD to standard SSD.
  • You can change the performance levels (PLs) of ESSDs for all RDS instances.
Storage capacity You can increase the storage capacity of all RDS instances.
Note
  • You cannot decrease the storage capacity of an RDS instance.
  • The new storage capacity that you specify for an RDS instance must be within the storage capacity range that is supported by the instance type of the RDS instance. For more information, see Primary ApsaraDB RDS instance types.
  • The storage capacity of a primary RDS instance must be greater than or equal to the storage capacity of its read-only RDS instances. If a read-only RDS instance is attached to a primary RDS instance, you must increase the storage capacity of the read-only RDS instance before you increase the storage capacity of the primary RDS instance.
  • If the storage capacity range that is supported by an instance type does not meet your business requirements, we recommend that you select another instance type.
  • When you increase the storage capacity of an RDS instance that runs SQL Server on RDS High-availability Edition with standard SSDs or ESSDs, a 30-second transient connection may occur. During the transient connection, most operations that are related to databases, accounts, and network settings cannot be performed on the RDS instance. We recommend that you increase the storage capacity of the RDS instance during off-peak hours or make sure that your application is configured to automatically reconnect to the RDS instance.
Note The endpoints of the RDS instance remain unchanged even if the preceding specifications of an RDS instance change.

Billing

For more information, see Specification change fees.

Precautions

  • A specification change may trigger a data migration. After the migration is complete, ApsaraDB RDS switches over your workloads during the switching time that you specify. The switchover does not interrupt the synchronization of incremental data. During the switchover, a 30-second transient connection may occur, and most operations that are related to databases, accounts, and networks cannot be performed. We recommend that you change the specifications during off-peak hours or make sure that your application is configured to automatically reconnect to your RDS instance.
  • You do not need to manually restart the instance after you change the specifications of your RDS instance.
  • In the RDS Basic Edition, your database system consists of only one primary RDS instance, and no secondary RDS instances are provided as standbys. If the primary RDS instance breaks down unexpectedly, your database service becomes unavailable. If you change the specifications or upgrade the database engine version of the primary RDS instance, your database service also becomes unavailable. The unavailability may last for a long period of time. If you require high service availability, we recommend that you select the RDS High-availability, Cluster, or Enterprise Edition.

Procedure

  1. Visit the RDS instance list, select a region above, and click the target instance ID.
  2. In the Configuration Information section of the page, click Change Specifications.
  3. In the dialog box that appears, select a change method and click Next step. This step is required only when your RDS instance uses the subscription billing method.
    Note You can select one of the following change methods:

    Upgrade or Downgrade

    The new specifications immediately take effect after you make the change. The two methods are supported for both subscription and pay-as-you-go RDS instances.

    After you start the specification change task, ApsaraDB RDS replicates the data of your RDS from the disk to a new RDS instance. Then, ApsaraDB RDS replicates other information about your RDS instance to the new RDS instance based on the change method that you select. This information includes the ID and endpoints of your RDS instance.

  4. Change the specifications of your RDS instances. For more information, see Change items.
  5. Specify the Switching Time parameter. Valid values:
    • Switch Immediately After Data Migration: The specification change triggers a data migration. If you select this option, ApsaraDB RDS immediately switches over your workloads after the data migration is complete.
    • Switch Within Maintenance Window: When you change the specifications, a 30-second transient connection may occur. During the transient connection, most operations that are related to databases, accounts, and network settings cannot be performed. If you select this option, ApsaraDB RDS applies the changes to the specifications during the maintenance window that you specify. For more information, see Set the maintenance window of an ApsaraDB RDS for PostgreSQL instance.
  6. Read and select Terms of Service, click Pay Now, and then complete the payment.

FAQ

  1. Can I change the zone and database engine version of my RDS instance?

    You can change the zone and database engine version of your RDS instance only if the instance runs SQL Server 2008 R2 with local SSDs. You can separately change the zone or you can also change the zone while you upgrade the database engine version. For more information, see Migrate an ApsaraDB RDS for SQL Server instance across zones in the same region and Upgrade an ApsaraDB RDS for SQL Server instance with local SSDs from SQL Server 2008 R2 to SQL Server 2012 or 2016.

  2. Do I need to migrate the data of my RDS instance to a new RDS instance when I increase the storage capacity of my RDS instance?

    No, you do not need to manually migrate the data. You need only to increase the storage capacity of your RDS instance. When you increase the storage capacity, ApsaraDB RDS checks whether the host where your RDS instance resides can provide sufficient storage capacity. If the host can provide sufficient storage capacity, ApsaraDB RDS increases the storage capacity without requiring you to migrate the data. If the host cannot provide sufficient storage capacity, ApsaraDB RDS migrates the data to a new RDS instance before it increases the storage capacity. The new RDS instance must be created on a host that provides sufficient storage capacity.

Related operations

API Description
ModifyDBInstanceSpec Changes the specifications of an ApsaraDB RDS instance.