Auto Flow Control

Auto Flow Control allows you to set criteria, such as the vCPU threshold and maximum number of active connections. When the criteria are met, auto flow control will be automatically triggered to ensure stability of your workloads.

Procedure

Log in to the management console.
Click in the upper left corner and select a region and project.
Click in the upper left corner, and under Databases, click Data Admin Service.
In the navigation pane, choose Intelligent O&M > Instance List.
Alternatively, on the Overview page, click Go to Intelligent O&M.
In the upper right corner of the Instance List page, search for instances by engine type, instance name, or instance IP.

Figure 1 Searching for instances
Locate the box containing your target instance and click Details.
Choose SQL > Auto Flow Control.

Figure 2 Auto flow control page

Auto Flow Control is not available to free instances. To use the function, set free instances as paid instances or subscribe to Intelligent O&M.
Click Auto Flow Control.

Figure 3 Auto flow control

In the displayed dialog box, set the control range, time, and policy and click OK.

Figure 4 Configuring auto flow control criteria

**Table 1** Auto flow control parameters
Parameter	Description
Database	Name of the database that you want to use Auto Flow Control for. If a database is specified, you need to run the use <database> statement before flow control takes effect for sessions.
Username	Name of the user that auto flow control is applied.
Time Window	Time when flow control is applied. Auto flow control can be triggered only once within the time window.
Max. Duration	Maximum length of time that SQL statements matching the auto flow control 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 vCPU usage and active sessions exceed the specified values. For example, if the CPU usage of an instance exceeds 90% and there are more than 1,000 active sessions, auto flow control will be executed for 30 minutes.
Max. Active Connections	Maximum number of active connections allowed. Value range: 1 to 5000 For example, if the maximum number of active connections is 500, the system automatically ends active connections to less than 500.