During stress testing, you can monitor the stress testing metrics of the stress testing scenario and APIs in real time. You can also modify the stress testing values to prevent the APIs from receiving a large number of requests and from being overloaded. This helps maintain system stability during the stress testing. Performance Testing Service (PTS) records the operations that you perform on stress testing scenarios for subsequent queries. This topic describes how to start a stress test, manually adjust the number of concurrent users, and view the operation records.
Start a stress test
Start a stress test. For more information, see Get started with the PTS-based stress testing and Get started with the JMeter-based stress testing.
The following figure shows the stress testing page.
Adjustment in PTS-based stress testing
Tiered increment mode
On the Executing Test page, click Scene speed regulation. Then, click Global Batch Speed Regulation or Business Session Speed Regulation to change the auto increment mode from Tiered Increment to Manual Adjustment, enter a stress testing value, and start the stress test. 
If you set the Stress Mode parameter in the Stress Mode Configuration section to RPS Mode (Requests Per Second) when you create a PTS-based stress testing scenario, you can adjust the number of concurrent users for each API.
If you click Global Batch Speed Regulation to change the auto increment mode to Manual Adjustment, the change takes effect for all APIs across all business sessions.
If you click Business Session Speed Regulation to change the auto increment mode to Manual Adjustment, the change takes effect only for the current business session. Other business sessions are not affected.
Manual adjustment mode
The method that is used to adjust the number of concurrent users in manual adjustment mode is consistent with the method in tiered increment mode. For more information, see Tiered increment. If you do not adjust the number of concurrent users in manual adjustment mode, the stress testing is implemented based on the current settings.
Adjustment in JMeter-based stress testing
On the Executing Test page, click Scene speed regulation. In the dialog box that appears, enter the number of users and click OK. 
Operation record
In the upper-right corner of the Edit Scenario page, click Records to view operation records, such as the start and stop of the stress test and scenario editing.