Group duration different from individual requests

Can someone please explain?

I have a scenario

`

val scenario1= scenario(“Scenario-Login”).during(durationInMinutes.toInt minutes) {
feed(user)
.group(“HomePage”){
exec(HomePage.homePage)
}.group(“LoginToTheSite”){
exec(LoginPage.loginToTheSite)
}
}

`

And i have edited the gatling.conf file to get group duration instead of cumulative response time.

useGroupDurationMetric = true # Switch group timings from cumulated response time to group duration.

but from results i am not able to understand the timings.

95th percentile of Group shows 60 seconds , but there is only one request inside the group which has a 95th percentile response time of 2.5 seconds

I have attached the screenshot below.

What does the code of “LoginPage.loginToTheSite” look like?
Which version of Gatling do you use?

Hi Stéphane

The code for “LoginPage.loginToTheSite” is

`

val loginToTheSite = exec(http(“Login to the site”)
.post("/en/header/login/request")
.headers(Headers.loginPageHeader_0)
.formParam(“CSRFToken”, “${csrf}”)
.formParam(“j_username”, “${username}”)
.formParam(“j_password”, “${password}”))

`

We are using GATLING_VERSION 2.3.0 .

Could you please share your simulation.log?

I have attached the log here. Thanks

simulation.log (4.65 MB)

There’s no issue with the simulation.log you provided (I verified with both 2.3.0 and 2.3.1).

I am getting the same result , when i tried with cumulated response time

After i comment this line in gatling.conf
#useGroupDurationMetric = true # Switch group timings from cumulated response time to group duration.

But with the
useGroupDurationMetric = true # Switch group timings from cumulated response time to group duration.

I am getting the same invalid response time.

Can you try with group duration please?

Could you please upgrade to 2.3.1?

Hi Stephane ,

I have executed the same test with 2.3.1 .
With editing the gatling.conf file to get group duration instead of cumulative response time.

useGroupDurationMetric = true # Switch group timings from cumulated response time to group duration.

Still i am getting invalid response time for 95th percentile in groups . Please find the screenshot below .

I have also attached the simulation.log file . I can say that the site is slow and some of the requests are getting timed out . But the group duration is not matching with the response time of individual requests . Is this a bug or there is a way to solve this issue?

simulation.log (1.37 MB)

Is there any way that you can privately share the actual simulation so I can run on my side?

Fixed: https://github.com/gatling/gatling/issues/3487

Thanks for reporting!

Thanks very much Stephane , for having time to look into this issue. Will wait for the next release version.

Hi Stephane , We have a performance test execution coming in few days . Is there a way we can incorporate this fix in current gatling version(2.3.0 or 2.3.1) . ?

We don’t have any release planned for the open source branch before Gatling 3 release candidates.
Until then, if you want to stick with OSS version, the best way is to back port on your side and build from sources.