jmeter thread group not running all assigned users

Question

I am running a recorded test plan. I have assigned 25 users in the Thread Group, with a Ramp-up Period of 25 and Loop Count of 1.

This is what happens:

1. Start the test.
2. While the test is running, in the upper right-hand corner the user number gets incremented to 9/25. At some level, the number remains constant 9/25 and then shows 8/25. After some time, the number automatically gets decremented by 1, 7/25....0/25.
3. In Database, I see the login entries for only 9 users.

Why does my test plan not run for the 25 users?

Answer 1

You have set total threads to be 25 with ramp-up period of 25 seconds. Which means that 1 user is created at every second.

So..

at 1st second.. # of users is =1
at 2nd second.. # of users is =1+1=2
at 3rd second.. # of users is =1+1+1=3
..
,,
at 9th second..  # of users is =9

at 10th second.. a new user is created but one of already created user also completes it test .. therefore it closes.. so the # of total users remain 9..

this trend goes on as some users are closing at one hand, while new users are being created on other hand.

If you want to put concurrent load of 25 users then you can achieve it in number of ways...

1. set the ramp-up period to 1 second (not a best approach for large tests)
2. use the synchronizing timer
3. use constant throughput timer
4. increase the number of users

Answer 2

The behavior is expected as when the thread has done its work and has nothing else to do it's getting stopped.

You need to provide enough users and loops (don't hesitate to set 100 to ensure that the users will be more or less unique) and use Constant Throughput Timer to orchestrate the load and set it 25 requests per second (or 1500 requests per minute).

Answer 3

Can you provide more details about values you have used in you Thread Group like it may be possible that you have used the setting 'Action to be taken after a Sampler error' as 'Stop Test' in this case as soon as JMeter encounters an error (which may be after 9 active users in your case) it will stop test and user count will start decreasing. But scenarios like these can be made more clear only after you provide complete information about the Thread Group and Setting of CSV file used (if any).

Regarding the expected behavior as mentioned in earlier response to this issue, even if thread has nothing else to do; then too it should log 25 entries i.e. one entry for each user, which is not the case, as only 9 entries are getting logged in database.