This topic describes how to change the specifications of an ApsaraDB RDS for SQL Server instance. The 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 RDS edition of an RDS instance from Basic Edition to High-availability Edition. For 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 for RDS instances that do not run RDS Cluster Edition. You cannot downgrade the storage type of the 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 read-only RDS instance cannot be less than the storage capacity of the primary RDS instance to which the read-only RDS instance is attached. If a read-only RDS instance is attached to a primary RDS instance and you want to increase the storage capacity for the instances, you must increase the storage capacity of the read-only RDS instance before you can 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, you cannot perform most of the operations that are related to databases, accounts, and network settings on the RDS instance. We recommend that you increase the storage capacity of your RDS instance during off-peak hours or make sure that your application is configured to automatically reconnect to your RDS instance.
Note The endpoints of an RDS instance remain unchanged after you change the preceding specifications of the RDS instance.

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 you cannot perform most of the operations that are related to databases, accounts, and networks on the RDS instance. 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.
  • After you change the specifications of your RDS instance, you do not need to manually restart the instance.
  • If your RDS instance runs RDS Basic Edition, no secondary RDS instance is provided as a hot standby. In this case, if your RDS instance unexpectedly exits, your database service may be unavailable for a long period of time. If you change the specifications or upgrade the database engine version of your RDS instance, your database service may also be unavailable for a long period of time. If you have high requirements for service availability, we recommend that you do not use RDS Basic Edition.

Procedure

  1. Access RDS Instances, select a region at the top, and then click the ID of the target RDS instance.
  2. In the Configuration Information section of the Basic Information page, click Change Specifications.
  3. In the dialog box that appears, select a specification change method and click Next step. This step is required only when the RDS instance uses the subscription billing method.
    Note You can select one of the following specification change methods:
    • Upgrade or Downgrade: After you submit a specification change order, the new specifications immediately take effect. Both specification change methods are supported for subscription RDS instances and pay-as-you-go RDS instances.
    • Elastic Upgrade: Elastic Upgrade allows you to upgrade the instance type and expand the storage capacity to improve the overall performance of the RDS instance. The instance type specifies the number of cores and the memory size. This method is not provided in the ApsaraDB RDS console. If you want to use this method, you must submit a ticket. When the date that is specified by the Restore Point-in-time parameter arrives, the instance type is automatically restored to the instance type that is used at the point in time before an elastic upgrade is performed. The storage capacity is not restored.

    After you submit a specification change order, ApsaraDB RDS synchronizes the data of the RDS instance from the disk to a new RDS instance. Then, ApsaraDB RDS switches the information, such as the ID and endpoints, about the RDS instance over to the new RDS instance based on the specification change method that you select.

  4. Change the specifications of the RDS instance. 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 to a new RDS instance. If you select this option, ApsaraDB RDS immediately applies the specification change and switches your workloads over to the new RDS instance after the migration is complete.
    • Switch Within Maintenance Window: When the specification change is being applied, a transient connection that lasts approximately 30 seconds may occur and you cannot perform most of the operations that are related to databases, accounts, and network settings. If you select this option, ApsaraDB RDS applies the specification change during the maintenance window that you specify. For more information, see Set the maintenance window of an ApsaraDB RDS for SQL Server instance.
  6. Read and select Terms of Service, click Pay Now, and then complete the payment.
    Warning
    • After you submit a specification change order, you cannot cancel the order. Therefore, before you submit a specification change order, we recommend that you evaluate whether the new specifications meet your business requirements.
    • After you submit a specification change order, do not perform DDL operations before the specification change is applied.

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 when the instance runs SQL Server 2008 R2 with local SSDs. You can change only the zone. 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 when you increase the storage capacity of your RDS instance. When you increase the storage capacity, ApsaraDB RDS checks whether the host on which your RDS instance resides can provide sufficient storage. If the host can provide sufficient storage, ApsaraDB RDS increases the storage capacity of your RDS instance without requiring you to migrate the data. If the host cannot provide sufficient storage, ApsaraDB RDS migrates the data to a new RDS instance before ApsaraDB RDS increases the storage capacity. The new RDS instance must be created on a host that provides sufficient storage.

Related operations

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