Help Center/ Relational Database Service_RDS for MariaDB/ User Guide/ Problem Diagnosis and SQL Analysis/ SQL Analysis/ Configuring Auto Throttling
Updated on 2025-07-23 GMT+08:00
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Configuring Auto Throttling

Auto throttling helps ensure availability of your workloads. It restricts the execution of SQL statements during peak hours or when there are read/write exceptions by limiting how many SQL statements can be executed at the same time.

After it is enabled, the system performs flow control on sessions when the criteria you specify for your instance are met (for example, the number of active connections to your instance exceeds the Max. Active Connections parameter value).

To use this function, subscribe to Intelligent O&M first.

Constraints

To use this function, submit a service ticket to request permissions.

Procedure

  1. Log in to the management console.
  2. Click in the upper left corner and select a region and a project.
  3. Click in the upper left corner of the page and choose Databases > Relational Database Service.
  4. On the Instances page, click the instance name to go to the Overview page.
  5. In the navigation pane, choose DBA Assistant > Historical Diagnosis.
  6. Choose SQL Explorer > Auto Throttling.
  7. Click Auto Throttling.
  8. Toggle on and configure required parameters. For details about the parameters, see Table 1.

    Example for setting auto throttling parameters

    Set Time Window to 15:00-18:00, Max. Duration to Last 5 minutes, vCPU usage ≥ to 90%, Active sessions ≥ to 20, and and Duration (min) to 5. When all the criteria are met, auto throttling is triggered. If your vCPU usage or number of active sessions falls below the threshold during the time window, auto throttling ends.

    Figure 1 Example
    Table 1 Parameter description

    Parameter

    Description

    Database

    The name of the database for which auto throttling needs to be enabled. Ensure that the database you select is consistent with the one specified in the use <database> statement, or auto throttling will fail.

    Username

    The name of the user that auto throttling is applied.

    If no username is specified, auto throttling will be applied to user root.

    Time Window

    The time when auto throttling is applied. Auto throttling can be triggered only once within the time window.

    Max. Duration

    Maximum length of time that SQL statements matching the auto throttling policy can be throttled within the time window.

    vCPU usage

    vCPU usage threshold for the instance. You also need to specify the relationship between the vCPU usage and active sessions. Their relationship can be and or or.

    Active sessions

    Threshold for active sessions. Value range: 1 to 5000

    Duration (min)

    How long the vCPU usage and active sessions exceed the specified values.

    For example, if you set vCPU usage ≥ to 90%, Active sessions ≥ to 1000, and Duration (min) to 30, auto throttling will be triggered only when the vCPU usage and active sessions exceed 90% and 1,000 for 30 minutes.

    Max. Active Connections

    Maximum number of active connections allowed. Value range: 1 to 5000

    For example, if you set Max. Active Connections to 500, the system will automatically end some active connections when necessary to keep the number of active sessions within 500.

  9. Click OK. You will see a record generated on the page every time auto throttling is triggered. You can see historical details, too.
Parent topic: SQL Analysis