Problem when i inject 50 virtual users in Gatling Simulation

When i inject 4 Virtual users in the Gatling simulation to execute POST request,

I get 1 failed request,

I used the feeders via a csv file to retrieve the data, actually the file contains only 3 lines as shown in the figure below


When, I injected 4 Virtual Users(VU) there is a 1 VU which cannot retrieve the ID-Restaurant

here is an extract from the simulation

I am confused if it is mandatory to have the data in the csv file equal to the number of virtauls users to inject ? i need help please

Your feeder is “circular”, so user 4 will grab the same record as user 1.
With your simulation, user 4 will generate the exact same request than user 1, meaning that this 400 Bad Request error you get is most likely a bug in the application. You should reach out to the developers of the application you’re testing so they investigate the reason of this 400.


Thank you Stéphane for your response.
But, in my opinion error 400 it is due to the problem of the recovery of the restaurant ID that is in the csv file. when I displayed the result in the terminal I have verified that the recovery of the lD for the user 4 is not carried out so the request is sent without ID, that’s why the return 400.

i did not undesrtand why this virtual user can’t extract value from csv file

Can you pls remove the empty line in csv file and try?

Sujin Sam

Thank you Sujin Sam for your help.

it works now

Great! But which version of Gatling do you use?

I use the version : 3.3.1

In the next release, we’ll be skipping those empty lines: