Change the specifications of an ApsaraDB RDS for MySQL instance - ApsaraDB RDS

This topic describes how to change the specifications of an ApsaraDB RDS for MySQL instance. The specification change includes RDS edition changes, instance type upgrades or downgrades, and storage capacity expansion or reduction.

For more information about all configuration items that can be changed for an RDS MySQL instance, see Configuration items for an ApsaraDB RDS for MySQL instance.

For configuration changes of other engines, see the following:

Prerequisites

The RDS instance uses the subscription or pay-as-you-go billing method.
Note
If the instance's billing method is Serverless, see Configure a serverless instance.
Your Alibaba Cloud account does not have unpaid renewal orders.
The RDS instance is in the Running state. If your RDS instance is in the Locked state, you must Unlock an instance before changing its specifications.

Limits

Specification change order: 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.
Read-only RDS instances specification change:
- When you change the specifications of a read-only RDS instance, the primary RDS instance to which the read-only RDS instance is attached must be in the Running state.
- The storage capacity of a read-only RDS instance must be greater than or equal to the storage capacity of its primary RDS instance. We recommend that you expand the storage capacity of all read-only RDS instances before you expand the storage capacity of the primary RDS instance.
Storage capacity reduction:
- Scaling down high-performance local disk instances
  - If you reduce the storage capacity of your RDS instance that uses Premium Local SSDs, the new storage capacity must be greater than or equal to 120% of used storage.
    For example, if the storage capacity of your RDS instance that uses Premium Local SSDs is 100 GB and 50 GB of storage is used, the new storage capacity must be greater than or equal to 60 GB, which is obtained by using the following calculation: 50 × 120%.
- General limits
  - You can reduce the storage capacity of your RDS instance that runs RDS Basic Edition or RDS High-availability Edition without the need to change the RDS edition or the architecture of the RDS instance.
  - The minimum value for storage reduction is calculated as: min{Current usage×1.3, Current usage+400 GB}, and must be greater than or equal to the minimum storage space supported by the current specifications.
  - You can reduce the storage capacity at a step size of 5 GB.
  - When binary logs are generated quickly for an instance, sufficient logs must be retained locally before the instance can be reduced in size. For information on how to enable log backup, see Modify RDS backup policy.
Product type change:
- Zone compatibility
  The zones supported by YiTian RDS instances are different from those supported by standard RDS instances. Before you change the product type of your RDS instance, you must perform the following operations:
  1. Check the available zones for the target type. 2. Migrate the instance to the target zone (Perform cross-zone migration). 3. Change the specifications.
- Kernel version constraints
  Make sure that the minor engine version of the RDS instance after the change is later than or the same as the current minor engine version. If the minor engine version after the change is earlier than the current minor engine version, the change fails.
Phased-out instance type change: You cannot directly change the specifications. You must first upgrade the configuration to an instance type that is commercially available before you can perform subsequent change operations.
Other limits: Only the configuration items that are described in Configuration items can be changed.

Impacts

Storage type	Configuration item	Impact
RDS instance that uses Premium Local SSDs	Instance type, RDS edition, and storage capacity	If the host on which your RDS instance is deployed cannot provide sufficient resources, the system migrates the data of your RDS instance to a new RDS instance. The incremental data that is generated in your RDS instance during the migration process is synchronized to the new RDS instance. After the migration process is complete, the system switches your workloads over to the new RDS instance during the switching time that you specify. Important A specification change causes an instance switchover. The switchover typically lasts about 30 seconds (however, if the client configuration is improper or the driver version is too old, the impact time may be longer). We recommend that you change specifications during off-peak hours. Make sure that your application has an automatic reconnection mechanism. During an instance switchover, you cannot perform most of the operations that are related to databases, accounts, and network settings. For more information, see Impacts of an instance switchover.
Disk instance	Specification or series	The specification change is complete within minutes. The time that is required to change the specifications is not affected by the data volume of your RDS instance. Important A specification change causes an instance switchover. The switchover typically lasts about 30 seconds (however, if the client configuration is improper or the driver version is too old, the impact time may be longer). We recommend that you change specifications during off-peak hours. Make sure that your application has an automatic reconnection mechanism. During an instance switchover, you cannot perform most of the operations that are related to databases, accounts, and network settings. For more information, see Impacts of an instance switchover.
Disk instance	Storage capacity	When expanding: Standard SSD expansion will cause transient connections, while ESSD and premium performance disk expansion do not cause transient connections. When reducing: Cloud disk reduction will cause transient connections. For more information, see Cloud disk storage space reduction (standard SSDs do not support reduction). Note If a snapshot backup task exists on your RDS instance that uses cloud disks, you can expand the storage capacity and upgrade the performance level of cloud disks only after the snapshot backup task is complete.

Note

After you change the specifications of your RDS instance, you do not need to manually restart the instance. The specification change does not cause loss of stored data.
After you change the specifications of your RDS instance, the ID and endpoints of the instance remain unchanged. However, if the instance is migrated to another server, the IP address that maps to the endpoints changes. We recommend that you use endpoints to access your RDS instance.

Billing rules

For more information, see Specification change fees.

Procedure

Important

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.

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, click Change Specifications.
(This step is required only for subscription instances) In the dialog box that appears, select a specification change method and click Next.
You can select one of the following specification change methods:
Upgrade or Downgrade: After the configuration change, the new configuration takes effect immediately. Both subscription instances and pay-as-you-go instances support immediate upgrade and downgrade.
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 original RDS instance over to the new RDS instance based on the switching time that you specified for the specification change. You can use the same ID and endpoints to connect to your RDS instance.
Modify the instance configuration.
Note
- You can change the instance type and storage capacity for all instance types. Phased-out instance types must first be upgraded to commercially available specifications before expanding storage capacity. For information about instance type changes, see Instance types for standard primary ApsaraDB RDS for MySQL instances (original x86 architecture).
- You can reduce the storage capacity of an RDS instance that runs RDS High-availability Edition with Premium Local SSDs, or runs RDS Basic Edition or RDS High-availability Edition with cloud disks (except standard SSDs). Other instances do not support storage capacity reduction.
- If the RDS instance runs MySQL 5.6 on RDS Enterprise Edition, you can downgrade the RDS instance to RDS High-availability Edition.
- If the RDS instance runs MySQL 5.7 on RDS Basic Edition, you can upgrade the RDS instance to RDS High-availability Edition with Premium Local SSDs.
- If the RDS instance runs MySQL 5.7 or MySQL 8.0 on RDS High-availability Edition with ESSDs, you can upgrade the RDS instance to RDS Cluster Edition.
- On the Change Specifications page, the instance type defaults to Current Specifications. Please ensure that the parameters of the adjusted instance specifications meet your requirements to avoid related risks.
Select Switching Time.
- Execute Immediately: Switch immediately after data migration.
- Switch Within Maintenance Window: The system switches your workloads over to the new RDS instance within the maintenance window that you specify.
Important
- If you select Switch Within Maintenance Window, the instance will remain in the Upgrading Or Downgrading state until the switchover is complete. During this period, you cannot perform instance-level operations such as specification changes, version upgrades, or cross-zone migrations on this instance.
- In most cases, when you only increase storage space or change the ESSD storage type, there is no impact on your business. The changes take effect immediately after configuration change, and you don't need to select Switch Within Maintenance Window.
- If you use RDS Basic Edition, no secondary RDS instance is provided as a hot standby for your RDS instance. Therefore, your database service becomes unavailable for a long period of time when you change the specifications of the RDS instance. We recommend that you change the specifications of the RDS instance during off-peak hours to prevent interruptions to your workloads.
- If you do not use RDS Basic Edition, one or two instance switchovers may occur when you change the specifications of the RDS instance. The switchovers do not interrupt your workloads. However, we still recommend that you change the specifications of the RDS instance during off-peak hours or make sure that your application is configured to automatically reconnect to the RDS instance. For more information about the impacts of an instance switchover, see Impacts of an instance switchover.
Read and select Terms of Service, click Pay Now, in the dialog box that appears, confirm the instance information before and after the specification change, 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

Storage capacity expansion or reduction

Why is my RDS instance still locked after I expand the storage capacity of the instance?
A: When a disk is locked because it is full, after expansion, you need to wait for the upgrade task to complete for automatic unlocking. You can click the button in the upper-right corner of the instance Basic Information page to go to the Task List page and check the progress of the expansion task.
When I expand the storage capacity of my RDS instance, why does a transient connection occur?
A: Storage expansion requires an instance switch. For details about the transient connection impact, see Impacts of an instance switchover.
Is the free quota on backup storage increased after I expand the storage capacity of my instance?
A: Yes. For more information, see Free backup quota.

Storage type change

How do I change the storage type of my RDS instance between Premium Local SSD, standard SSD, and ESSD?
A: For more information, see How do I change the storage type of an ApsaraDB RDS instance from cloud disk to local disk?.
How do I enable the automatic storage expansion feature for an RDS instance that uses Premium Local SSDs?
A: You can change the storage type from Premium Local SSD to cloud disk and then set up automatic expansion, or purchase a new instance with cloud disks and migrate your data.
How do I expand the storage capacity of my RDS instance that uses Premium Local SSDs after the upper limit is reached?
A: For information about the storage capacity range of RDS MySQL 8.0 and 5.7 High-availability Edition instances with Premium Local SSDs, see RDS MySQL High-availability Edition (Premium Local SSD). If you need to increase storage capacity, you can change from Premium Local SSD to cloud disk to obtain a higher storage limit.

Storage capacity management

When I expand the storage capacity of my RDS instance, what do I do if an error that indicates insufficient storage resources occurs?
A: We recommend migrating to a different zone before expanding capacity. After migration, the connection address remains unchanged but the IP address will change, so you need to configure your application to automatically reconnect.
If I expand only the storage capacity of my RDS instance, does the system migrate the data of my RDS instance to a new RDS instance?
In most cases, if your RDS instance uses cloud disks and does not run RDS Basic Edition, no transient connections occur when you expand the storage capacity. If your RDS instance uses Premium Local SSDs, the system migrates the data of your RDS instance based on the storage resources on the host on which your RDS instance is deployed:
- The host on which your RDS instance is deployed can provide sufficient storage resources. In this case, you can directly expand the storage capacity. The expansion process does not interrupt your workloads.
- The host on which your RDS instance is deployed cannot provide sufficient storage resources. In this case, the system creates a primary RDS instance and a secondary RDS instance on a different host that can provide sufficient storage resources. Then, the system synchronizes the data of your original RDS instance to the new primary and secondary RDS instances. After the synchronization is complete, a switchover is triggered and a transient connection that lasts approximately 30 seconds occurs.
Note
You cannot obtain the amount of available storage in the host on which an RDS instance is deployed.
If I delete a database from an RDS instance, is the disk space released?
A: Executing the DROP statement releases space; the DELETE statement generates fragmentation and does not release disk space.

Specification upgrade impacts

If I upgrade the CPU cores, memory, and storage capacity of my RDS instance at the same time, how long is the service downtime?
Whether you upgrade a single item or multiple items, the downtime is in minutes. During the specification upgrade, an instance switchover may occur, or your RDS instance may be restarted. In addition, 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 about the impacts of different configuration items, see Impacts of configuration changes.
What factors affect the period of time that is required to change the specifications of my RDS instance?
A: For more information, see Which factors affect the time that is required to change the specifications of my ApsaraDB RDS for MySQL instance?.
When I change the specifications of my RDS instance, are my online workloads interrupted?
A: For more information, see Impacts.

Read-only RDS instance management

When I upgrade my primary RDS instance, does the system automatically upgrade the read-only RDS instances that are attached to my primary RDS instance?
No, when you upgrade your primary RDS instance, the system does not automatically upgrade the read-only RDS instances that are attached to your primary RDS instance. You must manually upgrade the read-only RDS instances.
When I expand the storage capacity of my primary RDS instance, is primary/secondary replication affected?
A: No, there is no impact.

Connections and network settings

After I change the specifications of my RDS instance, do the endpoints of my RDS instance change?
A: The connection address (such as rm-bpxxxxx.mysql.rds.aliyuncs.com) remains unchanged, but the IP address may change. We recommend that you use the connection address rather than the IP address in your application.
How do I configure an application to automatically reconnect to an RDS instance?
A: For Java applications, we recommend setting the TTL to no more than 60 seconds to ensure that when the VIP address of the connection address changes, the application can receive and use the new VIP address of the resource by querying DNS again. For information about how to set TTL in Java, see official JDK documentation.

Instance type and billing

Can I convert a regular RDS instance into a serverless RDS instance?
No, you cannot convert a regular RDS instance into a serverless RDS instance. If you want to use a serverless RDS instance, you must create a serverless RDS instance. For more information, see Create a serverless ApsaraDB RDS for MySQL instance.
How am I charged for automatic storage expansion?
A: By default, the automatic storage expansion feature is disabled. In this case, you are not charged for the feature. If you enable the feature, you are charged for the feature based on the billing rules that are used for manual storage expansion. For more information, see Change instance specifications.
I unexpectedly downgrade the specifications of my RDS instance and then immediately upgrade the instance to the original specifications. Why does a great difference exist between the refund amount and the paid amount?
When you purchase your RDS instance, you may enjoy discounts. However, when you upgrade the specifications, no discounts are provided, and the price increases.

Automatic storage expansion and reduction

What are the rules for automatic storage expansion?
A: For more information, see Configure automatic storage expansion.
If I reduce the storage capacity of an RDS instance that uses cloud disks, what are the impacts?
A: Cloud disk reduction will cause transient connections. For more information, see Cloud disk storage space reduction.
Can I reduce the storage capacity of an RDS instance that uses Premium Local SSDs?
A: Yes, you can. When the instance is in the running state, click Change Specifications and then select Downgrade.

Cross-zone migration

How do I change single-zone deployment to multi-zone deployment?

A: For more information, see Perform cross-zone migration.

Related API

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