This topic describes how to change the specifications of an ApsaraDB RDS for SQL Server instance. The specifications include the storage type, instance type, and storage capacity. If the driver for SQL Server is updated on your RDS instance, you can expand the storage capacity of the RDS instance without data loss. If you change only the PL of the storage type and the storage capacity of your RDS instance, you do not need to specify the switching time for the RDS instance.

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. If your RDS instance uses a general-purpose or dedicated instance type, you can use Data Transmission Service (DTS) to migrate data from the source RDS instance to the destination RDS instance. For more information, see Overview of data migration methods.

Change items

You can create read-only RDS instances to offload read requests from a primary RDS instance in your database system. This way, the read capability of your database system is increased. 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 itemDescription
Database engine versionThe database engine versions of specific RDS instances can be upgraded. For more information, see the following topics:
RDS editionYou can upgrade the RDS edition of an RDS instance from RDS Basic Edition to RDS High-availability Edition. For more information, see Upgrade an ApsaraDB RDS for SQL Server instance from Basic Edition to High-availability Edition.
Instance typeYou can change the instance types of all RDS instances.
Storage type
  • You can upgrade the storage type of an RDS instance that does not run RDS Cluster Edition from standard SSD to ESSD. After you upgrade the storage type of an RDS instance from standard SSD to ESSD, you cannot downgrade the storage type from ESSD to standard SSD.
    Note If your RDS instance runs RDS Cluster Edition, you cannot upgrade the storage type of the RDS instance. If you want to upgrade the storage type of the RDS instance, you must create an RDS instance that uses ESSDs and then migrate the data of the original RDS instance to the new RDS instance. For more information, see Create an ApsaraDB RDS for SQL Server instance and Migrate data between ApsaraDB RDS for SQL Server instances.
  • You can change the PLs of ESSDs for all RDS instances regardless of the database engines. If you change the PL of the ESSD storage type of an RDS instance, you must configure the switching time.
Storage capacityYou can increase the storage capacity of all RDS instances.
Note
  • You cannot decrease the storage capacity of an RDS instance.
  • You can increase the storage capacity of an RDS instance at a step size of 5 GB. The new storage capacity cannot exceed the maximum storage capacity 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 RDS 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 the instance type of an RDS instance 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 and uses standard SSDs or ESSDs, a transient connection that lasts approximately 30 seconds 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.
  • You can expand the storage capacity of an RDS instance without data loss only when the driver for SQL Server is updated on the RDS instance. If you change the PL of the storage type and the storage capacity of your RDS instance, you do not need to specify the switching time for the RDS instance.
    Note
    • Storage capacity expansion without data loss indicates that you do not need to specify the switching time for the RDS instance if you change only the PL of the storage type and the storage capacity. If you also change the instance type of your RDS instance, you must specify the switching time.
    • If you do not change the specifications of your RDS instance but the Switching Time parameter is displayed on the Change Specifications page, the driver of your RDS instance is not updated. In this case, storage capacity expansion without data loss is not supported for your RDS instance. You can upgrade the major engine version or update the minor engine version of your RDS instance and then change the specifications to expand the storage capacity without data loss. For more information, see Upgrade the major engine version and RDS edition of an ApsaraDB RDS for SQL Server instance.

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: You can upgrade the specifications including CPU cores, memory capacity, and storage capacity of an RDS instance to increase overall database performance. This specification change method is available only to users in a whitelist. When the time 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, the system synchronizes the data of the RDS instance from the disk to a new RDS instance. Then, the system 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.
    Note If the driver for SQL Server is updated on your RDS instance, you can expand the storage capacity of an RDS instance without data loss. If you change only the PL of the storage type and the storage capacity of your RDS instance, you do not need to specify the switching time for the RDS instance. For more information, see Precautions.
  5. Configure 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.
    Note If your change only the PL of the storage type and the storage capacity of your RDS instance in Step 4, the Switching Time parameter is not displayed, and you do not need to specify the switching time of the RDS instance.
  6. Read and select Terms of Service and click Pay Now. In the dialog box that appears, confirm the instance information before and after the specification change and click Continue to complete the payment.
    Warning
    • After you submit a specification change order, you cannot cancel the order. 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

  • 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 RDS instance runs SQL Server 2008 R2 with local SSDs. You can separately change 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.

  • If I want to expand only the storage capacity of my RDS instance, do I need to migrate the data of my RDS instance to a new 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, the system checks whether the host on which your RDS instance resides can provide sufficient storage. If the host can provide sufficient storage, the system increases the storage capacity of your RDS instance without requiring you to migrate the data. If the host cannot provide sufficient storage, the system migrates the data to a new RDS instance before the system increases the storage capacity. The new RDS instance must be created on a host that provides sufficient storage.

  • How long does it take to change the specifications of an RDS instance?

    A specification change involves data migration. In approximately 90% of the cases, a specification change is complete within 30 minutes.

  • If I upgrade the CPU cores, memory, and storage capacity of an RDS instance at the same time, how long does a transient connection last?

    The transient connection lasts the same as the transient connection that occurs when you separately upgrade the CPU cores, memory, or storage capacity of an RDS instance. In most cases, the transient connection lasts for a few minutes. When the system switches your workloads, a transient connection may occur, or your RDS instance may be restarted. During the switchover, you cannot perform most of the operations that are related to databases, accounts, and network settings. We recommend that you change the specifications of your RDS instance within the specified maintenance window. For more information, see the "Change items" section of this topic.

Related operations

OperationDescription
ModifyDBInstanceSpecChanges the specifications of an instance.