Database Autonomy Service (DAS) analyzes the modifiable parameters of your ApsaraDB RDS for MySQL or PolarDB for MySQL instance, flags suboptimal settings, and shows parameter modification records from the past seven days — so you can tune performance without deep database expertise.
Prerequisites
Before you begin, make sure that:
Your database engine is ApsaraDB RDS for MySQL or PolarDB for MySQL.
Your database instance is connected to DAS and in the Accessed state. For connection instructions, see Connect a database instance to DAS.
Limitations
Only one diagnostics task can be triggered within a three-minute window.
If the interval between two consecutive diagnostics tasks is short, the returned results may be the same.
Parameter diagnostics analyzes only parameters that are modifiable in the ApsaraDB RDS or PolarDB console. It does not modify any parameter values — all changes must be made in the ApsaraDB RDS or PolarDB console.
How it works
DAS retrieves the topology of the instance, including the primary instance and all read-only instances.
It evaluates parameter settings against the instance status, parameter templates, benchmark concepts related to additional parameters, calculation formulas, and expertise.
It produces a diagnosis report containing the static parameter analysis and parameter modification records from the past seven days.
Usage notes
Applying parameter recommendations in the ApsaraDB RDS or PolarDB console may require a database restart. Schedule changes during off-peak hours and confirm that your application supports automatic reconnection.
Parameter diagnostics analyzes modifiable parameters and does not alter their values. To modify parameters, use the ApsaraDB RDS or PolarDB console — see Set instance parameters for ApsaraDB RDS for MySQL, or Configure cluster and node parameters for PolarDB for MySQL.
Billing
No fees are involved.
Run a diagnosis
Log on to the DAS console.
In the left navigation pane, click Intelligent O&M Center > Instance Monitoring.
Find your instance and click the instance ID to open the instance details page.
In the left navigation pane, click Diagnostics.
Click the Parameter Diagnostics tab.
Click Analyze to start a diagnostics task. The task appears in the Parameter Diagnostics section.
View and act on results
In the Parameter Diagnostics section, find the task and click Details in the Actions column.
To filter results by time, specify the time range you want to view.
Each finding includes a Recommendation Level that indicates urgency:
| Level | Meaning | Recommended action |
|---|---|---|
| Critical | Immediately modify this parameter. | Modify the parameter as soon as possible. |
| Warn | Modify based on your business requirements. | Evaluate and modify based on your business requirements. |
| Notice | The parameter value differs from the instance's default parameter template. | Review and adjust if needed. |
To apply a recommendation, click Parameter Settings on the analysis results page. This opens the ApsaraDB RDS or PolarDB console where you can modify the parameter. For modification steps, see Set instance parameters for ApsaraDB RDS for MySQL, or Configure cluster and node parameters for PolarDB for MySQL.