Send different POST json for concurrent apache bench requests

Question

Is there a way to send different body for a post request when using apache bench?

Here is my query

ab \
  -n 5 \
  -c 3 \
  -T "application/json" \
  -v 4 \
  -p my_json_body.json \
  http://localhost:8080/myendpoint

Here is my json

# my_json_body.json
{ "foo": "bar" }

What I want to do is to send a different json body for half of my concurrent requests (-c means concurrent)

So if I send four requests at a time, I want two of them to send

{ "foo": "bar" }

and I want two of them to send

{ "hi": "bye" }

Is this possible? The docs do not mention it as a possibility but it seems like it is a feature that might be in there somewhere. https://httpd.apache.org/docs/2.4/programs/ab.html

Answer 1

The answer I used and recommend is to write a bash script to run ab twice concurrently and pass different json to the two instances of ab. See Execute multiple shell scripts concurrently for bash concurrency advice