Change RDS for SQL Server instance specifications - ApsaraDB RDS

Note

To change serverless RDS for SQL Server instance specifications, use Change the scaling range of RCUs and Increase storage capacity.

Changes

The following specification changes do not affect instance endpoints. To scale out read capacity, create a read-only instance and configure read/write splitting. The primary instance must use Cluster Edition.

Item	Description
Version	You can upgrade the database engine version.
Edition	You can upgrade from Basic Edition to High-availability Edition or Cluster Edition, or from High-availability Edition to Cluster Edition.
Instance type	If the instance family remains unchanged and you only need to change the specification code: You can use the Change Specifications entry point. For example, if the instance family is general-purpose, you can change the instance type from `mssql.s2.medium.s2` to `mssql.s2.large.s2`. To change the instance family: Use the Upgrade Version entry point to move to the same or a higher-tier family, except in some cases. Family ranking (low to high): Shared < General-purpose < Dedicated. Downgrades are not supported. For example, you can change the instance family from general-purpose to dedicated. Note You cannot directly upgrade an instance from a shared instance type in the High-availability Edition to a dedicated instance type in the Cluster Edition. If the target instance family is not available in the console, create a new instance in the target instance family and then migrate data from the original instance to the new instance.
Storage type	For ESSD instances, you can upgrade the PL (for example, from PL1 to PL2). PL downgrades are not supported. Non-Cluster Edition instances can upgrade from standard SSD to ESSD. Downgrades from ESSD to standard SSD are not supported. Note Cluster Edition instances cannot upgrade from standard SSD to ESSD. Instead, create a new ESSD instance and migrate data from the original instance.
Storage capacity	You can only increase the storage capacity. Decreasing the storage capacity is not supported. Minimum increment: 5 GB. Total capacity cannot exceed the storage capacity limit of the current instance type. Note A read-only instance's storage capacity must be at least equal to its primary instance's. Increase read-only instance storage before expanding the primary instance. If the current instance type's storage range is insufficient, select a different instance type.

Prerequisites

Your Alibaba Cloud account has no unpaid renewal orders.

Usage notes

Specification changes may involve cross-host migration, which deletes host-level programs (SSIS, SSAS, SSRS) and accounts on the original host. Back up or migrate these resources in advance.

Important
ApsaraDB RDS for SQL Server is built on the native Microsoft SQL Server engine and focuses on providing stable and efficient managed database services. If your business requires features such as SSIS, SSAS, or SSRS, you need strong operations expertise to ensure business continuity.
Specification changes may trigger data migration and a switchover at your selected time. Incremental data is synchronized during this period. The switchover causes a brief interruption of about 30 seconds, during which most database, account, and network operations are unavailable. Perform changes during off-peak hours and ensure your application supports automatic reconnection.
Basic Edition has a single node with no hot backup. Extended downtime may occur during failures or specification changes. For high availability, use High-availability Edition instead.
Before expanding a primary instance's storage, ensure each read-only instance's storage capacity is greater than or equal to the primary instance's. Expand all read-only instances first.

Billing

Pricing details: Billing for 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 Basic Information section of the Configuration Information page, click Change Specifications.
(Subscription instances only) In the dialog box, select a change method (Upgrade or Downgrade: the new specifications take effect immediately) and click Next.

After submission, the system synchronizes data to a new instance and performs the switchover at the scheduled switchover time. The instance ID and endpoint remain unchanged.
Modify the instance specifications. Changeable items are listed in Changes.
Important
- Some instances support seamless storage expansion. When you only change the storage type PL or expand storage capacity, database access is not interrupted and no switchover time is needed. If you also change the instance type, a switchover time is required.
- If the Change Specifications page shows the Switchover time option without any specification changes, your instance does not support seamless expansion. Upgrade the engine version first to enable this feature.
Select when to apply the new specifications.
- Switch Immediately After Data Migration: Switchover starts immediately after data migration completes.
- Switch Within Maintenance Window: Switchover occurs during your configured maintenance window.
Note
- Instances that support seamless storage expansion skip this setting automatically.
- If you select Switch Within Maintenance Window, regular backups are disabled during the specification change.
On the Change Specifications page, confirm the instance information before and after the configuration change, and then click Pay Now to complete the payment.
Warning
- To ensure a stable configuration change, do not perform DDL operations from the time you submit the order until the change is complete.

FAQ

Does changing the PL of the storage type interrupt database access?

Some instances support seamless storage expansion. When you only change the storage type PL or expand storage capacity, database access is not interrupted and no switchover time is needed. If you also change the instance type, a switchover time is required.
If the Change Specifications page shows the Switchover time option without any specification changes, your instance does not support seamless expansion. Upgrade the engine version first to enable this feature.

Can I change the zone and version?

For instances not running SQL Server 2008 R2: Call the ModifyDBInstanceSpec API operation to upgrade the major database version and change the zone and vSwitch. You can also upgrade the major database version in the console.
For SQL Server 2008 R2 instances with high-performance local disks: Upgrade the version and change the zone simultaneously in the console.

Note

You can also migrate the zone separately.

If I only expand the storage capacity, do I need to migrate data to a new instance?

No. The system expands capacity in place if the current host has enough space, or automatically migrates data to a host with sufficient space.

How long does a specification change take?

In 90% of cases, a specification change completes within 30 minutes.

If I upgrade the CPU, memory, and disk at the same time, how long will the brief interruption last?

The interruption lasts about 30 seconds regardless of whether you change CPU, memory, and storage together or separately. During the switchover, a service interruption or instance restart may occur. Most database, account, and network operations are unavailable. Perform specification changes within your maintenance window. Changeable items are listed in Changes.

Related API operations

ModifyDBInstanceSpec