ApsaraDB RDS:Change the specifications of an ApsaraDB RDS for SQL Server instance

Change items

To increase the read capability of your database system, you can create read-only RDS instances to offload read requests from primary RDS instances. 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.

Prerequisites

Your Alibaba Cloud account does not have overdue renewal orders.

Usage notes

• 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.

• A specification change may trigger a data migration. After the migration is complete, the system 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 RDS 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 select other RDS editions such as RDS High-availability Edition.

• If a read-only RDS instance is attached to your primary RDS instance and you want to expand the storage capacity, make sure that the storage capacity of the read-only RDS instance is greater than or equal to the storage capacity of the primary RDS instance. If the preceding condition is not met, the storage capacity cannot be expanded. We recommend that you expand the storage capacity of the read-only RDS instance before you expand the storage capacity of the primary RDS instance.

Billing rules

For more information, see Specification changes.

Procedure

1. Go to the Instances page. In the top navigation bar, select the region in which the RDS instance resides. Then, find the RDS instance and click the ID of the 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 for subscription RDS instances.

   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, 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.

   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.

   • Storage capacity expansion without data loss indicates that you change only the PL of the storage type and the storage capacity. You do not need to specify the switching time for the RDS instance. 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.

5. Configure the Switching Time parameter.

   • Switch Immediately After Data Migration: The specification change triggers a data migration. If you select this option, the system immediately switches over your workloads after the data 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, the system 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

   You can expand the storage capacity of RDS instances without data loss when the drivers for SQL Server are updated on the RDS instances. In this case, the Switching Time parameter is not displayed on the Change Specifications page, and you do not need to specify the switching time for the RDS instances.

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 disks. 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 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 expand 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 your 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 Change items.

Related operations