response time anomaly in simulation summary

Gatling (Open-Source)
1

Hi,

I am using gatling 2.x for testing a REST api’s response times. My simulation code looks as follows:

val scn = scenario ("Login ").forever(exec(loginUser()))
setUp (scn.inject(rampUsers(1) over(2 seconds))).maxDuration(1 minutes)

At the end of the simulation, this summary is printed on the console:

Simulation finished
Generating reports…
Parsing log file(s)…
Parsing log file(s) done

simulation.log (22.3 KB)

2

Hi Krishna,

So it seems there’s an extra overhead for the first request.

  • Can you reproduce with latest Gatling version (2.1.6)?
  • Did you disable warm up? This is used to load all the HTTP client stack.
  • Is your application under test already started and warmed up when you start Gatling?
  • Are you sure there’s nothing wrong going on with DNS?
    Cheers,
3

Hi Stéphane,

Yes, it is reproducible with 2.1.6 also. I did not disable warmup. The application under test is already running. To discount any warmup issues on server side, I ran gatling simulations multiple times consecutively with similar results. Since multiple runs give similar results, it seems unlikely that this is a DNS issue. New log file is attached. There is some improvement in max response time, instead of ~min10x, it is more like min6x now.

thanks for your help, let me know if you need any more details.
Krishna

simulation.log (22.8 KB)

4

I’m afraid I can’t do anything if I don’t get a reproducer (app to be tested and simulation).