Gatling - Generating load

Generating load with Gatling

The recorded simulation is a single user walkthrough. This might be useful in some cases, but in general making it soak the application in requests will give you information on how it behaves under stress.

The most obvious way is to change

setUp(scn.inject(atOnceUsers(1))).protocols(httpProtocol)

to some variation of:

def users = 10
setUp(scn.inject(atOnceUsers(users))).protocols(httpProtocol)

A list of options that you could apply is here:

  setUp(
    scn.inject(
        nothingFor(4 seconds) // 1 
        ,atOnceUsers(5) // 2                                                           
        ,rampUsers(10) over(5 seconds), // 3                                  
        ,constantUsersPerSec(5) during(60 seconds) // 4                                        
        ,constantUsersPerSec(20) during(15 seconds) randomized // 5 
        ,rampUsersPerSec(1) to 5 during(10 minutes) // 6                            
        ,rampUsersPerSec(10) to 20 during(10 minutes) randomized, // 7 
        ,splitUsers(1000) into(rampUsers(10) over(10 seconds)) separatedBy(10 seconds), // 8  
        ,splitUsers(1000) into(rampUsers(10) over(10 seconds)) separatedBy atOnceUsers(30), // 9
        ,heavisideUsers(1000) over(20 seconds) // 10
    )
  ).protocols(httpProtocol)

( sourced from http://gatling.io/docs/2.1.1/general/simulation_setup.html )

The options are not necessarily clear-cut, and have a lot to do with test design. Read the guidance in the Gatling documentation - it’s well written and useful.