How to use Jmeter to carry out high concurrency in scenarios such as panic buying and seckill?

Main introduction here

Sync timer: Blocks the thread (accumulates a certain number of requests), when the specified time reaches the

strong>A certain number of threads, these threads will be released together at the same time point

Parameter introduction:
Number of Simulated Users to Group by: The number of simulated users, that is, the number of threads to be released at the same time.
- If set to 0, it is equal to the number of threads set to the thread group

Timeout in milliseconds: Timeout time, that is, how many milliseconds after the timeout, the specified number of threads will be released at the same time;
-If set to 0, the timer will wait for the number of threads to reachThe set number of threads is released until the set number of threads is reached. If the set number of threads is not reached, it will continue to die.

-If it is greater than 0, then if the set number of threads has not been reached after the maximum waiting time set in Timeout in milliseconds,
Timer will no longer wait and release the threads that have arrived.Default is 0

Steps

The first step, right-click on the test plan, add a thread group

Set the number of threads to: 100

Set the Ramp-Up time to: 10

The second step, add HTTP request, fill in the url to be concurrent

The third step, in the http request, add a synchronization timer,

Set Number of Simulated Users to Group by to: 20

Set Timeout in milliseconds (unit: milliseconds) to: 5000

The fourth step, right-click on the test plan, add a view result tree

Step 5, right-click on the test plan, add listener-aggregation report

The sixth step, run jmeter to view the aggregated report