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

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.

Note

For more information about how to change the specifications of a serverless RDS instance, see Change the scaling range of RCUs for a serverless ApsaraDB RDS for SQL Server instance and Expand storage capacity.

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.

Configuration item	Configuration
Database engine version	The database engine versions of specific RDS instances can be upgraded. For more information, see Upgrade the major engine version or Upgrade an ApsaraDB RDS for SQL Server instance with local disks from SQL Server 2008 R2 to SQL Server 2012 or SQL Server 2016.
RDS edition	You 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 type	You can change the instance types of all RDS instances.
Storage type	You can upgrade the performance levels (PLs) of Enterprise SSDs (ESSDs) for RDS instances that use the ESSD storage type. For example, you can upgrade the storage type from PL1 ESSD to PL2 ESSD. You cannot downgrade PLs of ESSDs. You can upgrade the storage type of an RDS instance that does not run RDS Cluster Edition from standard SSD to ESSD. After the upgrade is complete, 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 from standard SSD to ESSD. 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.
Storage capacity	You can expand the storage capacity of all RDS instances. However, you cannot reduce the storage capacity of an RDS instance. You can expand the storage capacity at a step size of 5 GB. The new storage capacity cannot exceed the maximum storage capacity that is supported by the instance type. For more information, see Primary ApsaraDB RDS instance types. Note 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 the requirement is not met and you want to expand the storage capacity for the primary and read-only 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 an instance type does not meet your business requirements, we recommend that you select another instance type. When you expand the storage capacity of an RDS instance that runs RDS High-availability Edition and uses cloud disks, a transient connection that lasts approximately 30 seconds occurs. 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 expand the storage capacity of your RDS instance during off-peak hours and make sure that your application is configured to automatically reconnect to the RDS instance.

Note

After you change the preceding specifications, the endpoints of your RDS instance remain unchanged.

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 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.
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

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.
In the Configuration Information section of the Basic Information page, click Change Specifications.
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.
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.
Change the specifications of the RDS instance. For more information, see Change items.
Note
- Storage capacity expansion without data loss indicates that you change only the PL of the storage type (such as ESSD PL1) 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.
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 switches over your workloads within 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 specific RDS instances without data loss. 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.
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. 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

Does the change of the PL of the storage type indicate that the storage capacity is expanded without data loss?

Storage capacity expansion without data loss indicates that you change only the PL of the storage type (such as ESSD PL1) 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.

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

If your RDS instance does not run SQL Server 2008 R2, you can call the ModifyDBInstanceSpec operation to upgrade the major engine version or change the region and zone of the instance. You can also upgrade the major engine version of your RDS instance in the ApsaraDB RDS console. For more information, see Upgrade the major engine version.
If your RDS instance runs SQL Server 2008 R2 and uses local SSDs, you can change the zone of the instance while upgrading the major engine version of the instance in the ApsaraDB RDS console. For more information, see Upgrade an ApsaraDB RDS for SQL Server instance with local disks from SQL Server 2008 R2 to SQL Server 2012 or SQL Server 2016.

Note

You can also change the zone of your RDS instance by migrating it to another zone in the same region. For more information, see Migrate an ApsaraDB RDS for SQL Server instance across zones.

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 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

Operation	Description
ModifyDBInstanceSpec	Changes the specifications of an instance.