对于 API 请求，无法在 Jmeter 中达到预期的事务/秒

Question

The required transactions/sec is 5.5/sec or 20,000/hour. And I have 6 API request with average response time as 1 sec each. Think time is 5sec between each API. By Little's Law, I should able to reach the target transaction with 30 threads. But I'm able achieve only 6000/hour which is very less compared to my target rate. Only 4-5 error as the application was down for few seconds. Later it was up an running. CPU, Memory utilizations were good. What could be the reason? Used Concurrency thread group and selected Stop Thread on Error option.

Answer 1

Are you sure about your "average response time as 1 sec each" because assuming your configuration with:

• 5 seconds think time between requests
• 6 API requests
• 1 second response time

it means that 1 user execute 1 request each 7 seconds which gives 514 requests per hour and 30 users will do 15420 (less than your "required" 20000 but more than 6000 you're getting)

Take a look at perceived response time using Aggregate Report listener, my expectation is that you will need to adjust the thinktime because real response time is much higher.

Also be aware that you don't need to apply any "laws" or "think times", there is Throughput Shaping Timer so it's sufficient to just add it and configure like:

and it will automatically slow down JMeter threads in order to maintain the defined number of requests per second.

Remember that the number of threads must be sufficient, the timer won't automatically add new threads if the current amount is not enough (unless you use special Feedback Function )