Questions about joshua

Hi there,
I see Joshua need a coordinating cluster to run. When I play Joshua, it seems that there is only one fdbserver process for running simulation, and it is on the joshua container. My questions are:
1 How can I launch multiple simulation processes for speeding up correctness test?
2 Is there any instruction to Joshua to run a specific test workload?
3 Are there any extra requirements for coordinating cluster? do they need to be configured with some test roles? Does the scale of coordinating cluster impact on the time to finish test?

The documentation for Joshua is not great, and there are some contents in fdb-joshua/ at main · FoundationDB/fdb-joshua · GitHub file.

  1. Yes. You can spawn as many Joshua agents as possible, each one runs a simulation in parallel to others.
  2. No exactly. The tests for Joshua are contained in the correctness package (a tar.gz file). By default, all tests under tests/fast, tests/slow, tests/rare, and tests/restarting subdirectories are included. You can modify the correctness package to only include the test you want to run.
  3. No specific requirements. No test roles needed. However, if you have thousands of Joshua agents, it’s better to provision more resources, since all agents download the correctness package from the coordinating cluster and write results back.

Thank you Jingyu. Your reply is very helpful to understand how to run Joshua.