What is the relationship between vusers and threads?

What is the relationship between vusers and threads? Was this post helpful ?

What is the relationship between vusers and threads? If set Constant User Count = 1000, is that means the constant 1000 vuser running during the test?

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Re: What is the relationship between vusers and threads? Was this post helpful ?

That is correct.

If you set a constant user count of 1000 you will see 1000 concurrent scenarios running at any given point during your load test.

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Re: What is the relationship between vusers and threads? Was this post helpful ?

Thanks for the quick reply!

So can we simply understand as 1 vuser = 1 thread ?
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Answer Re: What is the relationship between vusers and threads? Was this post helpful ?

The only relationship I know of is that vusers take threads to run on agents, and will likely generate threads on the system under test.. depending on what the tests are doing I suspect that a single vuser might generate more than one thread on the agent system that is running the user. How many threads get spawned to deal with the load generated by the vuser will again depend on what kind of requests the vuser is making, and the software running on the SUT.

Vuser is a Virtual user. the number of vusers you utilize is basically controlling how many webtests or unit tests will run in parallel in a loadtest scenario. How that equates to real users depends on factors like what actions the tests are doing, time between tests, and think times.

the number of vusers you use also controls the maximum simultanious (or nearly so due to travelling over a network) requests that can be generated at the same time against your SUT.

low think times and little to no time betweeen test iterations allows a single vuser to simulate the requests/time load of many real users. This is a good technique for something like a perfomance test, or measuring performance deltas due to code/hardware changes, where you want a consistent repeatable test.

a larger number of vusers, using realistic randomized think times, and longer times between test iterations could generate the same load in terms of transactions/hour as the no-think test, however the load would less constant, with a higher number of potential simultanious requests. This type of config is good for a more realistic classic 'load test' where you want ebb and flow in the level of requests at any one instant and it's not as important the test be repeatable
--Chuck

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Answer Re: What is the relationship between vusers and threads? Was this post helpful ?

"Threads" are a confusing term which is why we try not to use it.

A better way to think of it is:

1 Concurrent user = 1 user at a machine running through the scenario(s) you have defined.
So 1000 concurrent users = 1000 of those scenarios running at the same time.