Gatling 3.5.0 Batching feeder throws feeder empty

Gatling (Open-Source)
1

Hi,

val contactCreateScn = scenario("Contact Create Req")
  .exec(Auth.setHeaderValues)
  .repeat(10) {
    exec(
      RequestFormatter.postContactCreate
    ).exec(session => {
      println(">>>>>>>>>............"+session("contactId").as[String])
      writer.write(session("contactId").as[String])
      writer.write("\n")
      session
    })
  }

I have the above scenario to write values to a csv

I am using the below scenario ( the csv written above is used as feeder here )

val contactGetScn = scenario("Contact Get Req")
  .exec(Auth.setHeaderValues)
  .feed(csv("primarycontact.csv").batch(2))
  .repeat(5) {
    exec(
      RequestFormatter.getContact
    )
  }

My setup:

setUp(
  contactCreateScn.inject(atOnceUsers(1))
    .andThen(contactGetScn.inject(atOnceUsers(2)))
  ).protocols(http
    .baseUrl("https://bam.nr-data.net"))

But then I experience the below error

java.lang.IllegalStateException: Feeder is now empty, stopping engine

where as the contact create req is successful and could see values in csv too

2
  1. the column headers must be present when the simulation is created
  2. the file must be fully populated when the first chunk is read
3

  1. Yes there’s header in csv

  2. The data is written in parent scenario itself. Doesn’t it mean the data is already populated? As I don’t write any data to csv in the child scenario.

4

How many records do you write in the feeder file in the parent scenario?
How many records are you trying to pull from the feeder in the child one?

5

10 records.

trying to fetch batches of 2.

6

You have a flushing issue.
You’re most likely using a PrintWriter which is backed by a BufferedOutputStream.
You’re writing very little data, not enough to fill the buffer and trigger the flush, so you have to flush manually.

You need to flush at least twice:

  • after writing the headers line
  • once you’re done writing (you can do that by closing the writer as a first step in the child scenario)