Jmeter reading input parameters from dynamically appending file

Question

Please tell me, is it possible to read data into Jmeter from a dynamically changing file? I have a file with parameters, which will be appended during the test itself. Is it possible to somehow define a global counter that will allow each thread to read its own line every iteration? User Defined Variables are reset every iteration as i understood. In theory, I can read a specific line using File.readLines().get(counter) in JSR223 Sampler but problem is how to define correctly this counter.

Answer 1

I believe __counter() function is what you're looking for. If you invoke it like ${__counter(FALSE,)} it will return an incremented value each time it will be called.

Example usage:

More information: How to Use a Counter in a JMeter Test