How to run multiple experiments together?

RLlib
#1

Screenshot 2021-12-27 at 8.23.45 AM

THanks, team!

I notice, sometime there are only one experiment running, sometimes there are 2 experiments running at the same time, may I know what arguments can effect decide this?

#2

Did you use Tune? What is your resource allocation settings?

#3

Hi Roller44, THanks for your reply!! My script looks like this

config["num_gpus"] = 4
config["num_workers"] = 30
config["num_envs_per_worker"] =4
config["rollout_fragment_length"] =100
...skip a few other configs...

ray.init(num_cpus=40)
analysis = tune.run(
        ppo.PPOTrainer,
        config=config,
        local_dir=log_dir_play_ray,
        stop=stop,
        checkpoint_at_end=True,
        name=exp_name,
 )
ray.shutdown()
#4

Your configuration requires 30 * 4 = 120 CPUs (i.e., each of 30 workers requires 4 CPUs to run 4 environments, where, normally, each environment requires 1 CPU) to run all experiments in parallel but you only have 40 CPUs. So you should decrease num_workers or num_env_per_worker.

The bottom line is, the number of experiments running in parallel is equal to:

  1. <your_total_number_of_cpus> / (num_cpu_per_worker x num_workers x num_envs_per_worker + num_cpus_for_driver),
  2. <your_total_number_of_gpus> / (num_gpu_per_worker x num_workers + num_gpus).
#5

great! Thanks! I will have a try