Modify parameter settings for an RDS for MySQL database - ApsaraDB RDS

Modify parameter settings and view modification history for RDS for MySQL instances through the console or API. View instance parameters.

Usage notes

To ensure instance stability, only parameters available in the console can be modified. The set global command is not supported.
When modifying parameters, check the Value Range column on the Editable Parameters page. You can also use expressions to automatically adapt parameters to instance configuration changes.
Some parameters modified on the primary instance are automatically synchronized to read-only instances. Appendix: Synchronized parameters.
Notes on the lower_case_table_names parameter:
- MySQL 5.7, 8.0, and 8.4: Table name case sensitivity must be specified when you create the instance (default value: 1, case-insensitive). This parameter cannot be modified after the instance is created, and its value remains unchanged after an upgrade.
- MySQL 5.6:
  - This parameter can be modified after the instance is created, but the instance will be restarted. We recommend that you modify the parameter during off-peak hours.
  - If you want to change the value from 0 to 1, you must convert uppercase table names in the instance to lowercase beforehand. Otherwise, existing uppercase tables will become inaccessible.
  - Read-only instances do not support modifying this parameter. You must modify it on the primary instance, and the modification will be synchronized to read-only instances.

Important

Parameter modifications may require an instance restart or reconnection. Perform these operations during off-peak hours and ensure your application has an automatic reconnection mechanism:

Some parameters require an instance restart to take effect. Check the Force Restart column on the Editable Parameters page. A restart causes a connection interruption of about 15 seconds. Ensure your application has an automatic reconnection mechanism.
Parameters that do not require a restart take effect on new connections only. Existing connections must be reconnected.

Modify instance parameters

Modifiable parameters vary by MySQL engine version. List of modifiable parameters for RDS for MySQL.

Modify the parameters of a single instance

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 left navigation bar, click Parameters.

You can perform the following operations:

Modify single parameter

On the Editable Parameters tab, find the parameter that you want to modify and change its value based on the scenario:
- Click in the Running Parameter Value column, and enter a parameter value based on the suggested value range.
- In the Running Parameter Value column, select a parameter value from the drop-down list.
Click OK.
Click Apply Changes. In the dialog box that appears, select an effective time period. You can select Take Effect Immediately, Take Effect Within the Maintenance Window, or Take Effect at Specified Time.

Note
On the Scheduled Tasks for Parameter Modification tab, you can view parameter modification tasks for which you selected Take Effect Within the Maintenance Window or Take Effect at Specified Time.
(Optional) To cancel the parameter modifications before they are submitted, click Cancel Changes.

Apply and export templates

Apply a parameter template

RDS provides system parameter templates for scenarios such as high performance. You can also create custom templates to apply settings in batches. Use a parameter template.

Click Apply Template.
Select the parameter template to apply, and click OK.
Note
- The dialog shows parameter count and whether a restart is required. To view detailed changes, click View Parameter Change.
- If the parameter template is not listed, it may be in a different region. Copy the template to the instance's region. Use a parameter template.

Export a parameter template

Click Export as Template.

Configure the following parameters.

Parameter	Description
Template Name	Template name. 8 to 64 characters; allows letters, digits, periods (.), and underscores (_). Must start with a letter. Cannot contain Chinese characters.
Description	Description for the template. Up to 200 characters.

Click OK to create a new parameter template in the region.

Import and export parameters

To modify many parameters at once or save current settings, export a TXT file of all parameter values, edit it locally, and import it to apply changes.

Click Export Parameters to export the parameter file in TXT format.
After modifying the file, click Import Parameters and paste the file contents into the dialog box.
Click OK.
Click Apply Changes. In the dialog box that appears, select when the changes take effect. You can select Take Effect Immediately, Take Effect Within the Maintenance Window, or Take Effect at Specified Time.

Note
On the Scheduled Tasks for Parameter Modification tab, you can view parameter modification tasks where you selected Take Effect Within the Maintenance Window or Take Effect at Specified Time.
(Optional) To cancel parameter modifications before they are submitted, click Cancel Changes.

Important
If the Operation failed. The specified parameter format is invalid. error message appears, check whether the parameter value you entered is within the Valid Values.

Modify parameters for multiple instances

Log on to the ApsaraDB RDS console. In the left-side navigation pane, click Instances. In the top navigation bar, select the region in which the RDS instance resides.
Select the checkboxes to the left of multiple target instances and click Apply Changes at the bottom of the page.

Note
Instances in a batch parameter change must have the same version and series. Otherwise, the Modify Parameters button is grayed out and you cannot click it.
On the Parameters page that appears, click the icon to the far right of the name of the parameter to modify.
In the value box, select or enter a new value and click OK.
In the Parameters window that appears, verify that the changes are correct, and click OK.

View modification history

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 left navigation bar, click Parameters.
Click the Edit History tab.
Select the time range and click OK.

FAQ

Do parameter modifications take effect immediately? Is an instance restart required?

Some changes take effect in about 5 minutes without a restart. Others require a restart. Check the Editable Parameters page and the Force Restart column to confirm before submitting.

Why are my parameter modifications not applied?

Parameter modifications are applied only after you click Apply Changes.

If a read-only instance is of a High-availability Edition and has a primary instance and a secondary instance, how do I set parameters for both?

Set parameters only on the primary instance of the read-only pair. The parameters are then automatically synchronized to the secondary instance.

I want to modify the expire_logs_days or binlog_expire_logs_seconds parameter, but I cannot find it in the RDS console. What do I do?

The expire_logs_days and binlog_expire_logs_seconds parameters are used in open-source MySQL to control the retention period of the local binary log. However, RDS for MySQL does not use these parameters for this purpose. To modify the binary log retention period for an RDS for MySQL instance, you can set the binary log retention policy in the RDS console.

Note

To delete or reduce log and data backups for an RDS for MySQL instance, Delete or reduce backups.

How do I modify the lower_case_table_names parameter?

For more information, see Notes on the lower_case_table_names parameter.

When I use the set global command to modify a parameter, I get an error: Access denied; you need (at least one of) the SUPER or SYSTEM_VARIABLES_ADMIN privilege(s) for this operation. What should I do?

RDS for MySQL does not support the set global command. Only parameters available in the console can be modified.

How do I modify the collation_connection and collation_database parameters?

You cannot directly modify collation_connection or collation_database. Instead, set the init_connect parameter in the RDS console. Supported values include 'set names utf8mb4', 'set names utf8', 'set default_collation_for_utf8mb4=utf8mb4_general_ci', 'set default_collation_for_utf8mb4=utf8mb4_general_ci;set names utf8mb4', 'set names utf8mb4 collate utf8mb4_general_ci', and 'set names utf8mb4 COLLATE utf8mb4_bin'.

The system runs this command on each new connection, setting the character set and collation. Ensure your application does not override the session collation, or session-level settings take precedence.

Can I modify the sql_log_bin parameter?

No. RDS for MySQL enforces sql_log_bin for all sessions to ensure binary logs are persisted, maintaining data consistency for replication.

Why does the modification of the wait_timeout parameter not take effect?

Modifications to the wait_timeout parameter apply only to new connections. Existing connections must be disconnected and reconnected for the new value to take effect.

In an RDS instance, why is the performance_schema parameter enabled, but no records are found when I query the performance_schema.session_connect_attrs table?

Set the loose_performance_schema_session_connect_attrs_size parameter to a value greater than 0 in the RDS console.

Appendix: Synchronized parameters

The following parameters are automatically synchronized from the primary instance to all read-only instances when modified.

lower_case_table_names

Note
For RDS for MySQL 5.7, 8.0, and 8.4, table name case sensitivity can only be specified when you create the instance, and the lower_case_table_names parameter cannot be modified afterward. Only MySQL 5.6 supports modifying this parameter on the primary instance, with the change synchronized to read-only instances.
innodb_large_prefix
loose_validate_password_length
default_time_zone
rpl_semi_sync_slave_enabled
character_set_server
collation_server

API reference

API	Description
ModifyParameter	Modifies the parameters of an RDS instance.
DescribeParameterTemplates	Queries database parameter templates.
DescribeParameters	Queries the parameter configuration of an instance.