How to understand why below request fails using Gatling tool?

Gatling (Open-Source)
#1

https://sqa.stackexchange.com/questions/27415/how-to-understand-why-below-request-fails-using-gatling-tool

#2

It seems to be a concurrence problem. Are you stressing your localhost? What kind os application are you stressing? Whithout knowlege about you architecture it’s difficult answer.