ray/rllib/examples/fractional_gpus.py

117 lines
4.4 KiB
Python

"""Example of a custom gym environment and model. Run this for a demo.
This example shows:
- using a custom environment
- using a custom model
- using Tune for grid search
You can visualize experiment results in ~/ray_results using TensorBoard.
"""
import argparse
import ray
from ray import tune
from ray.rllib.examples.env.gpu_requiring_env import GPURequiringEnv
from ray.rllib.utils.framework import try_import_tf, try_import_torch
from ray.rllib.utils.test_utils import check_learning_achieved
tf1, tf, tfv = try_import_tf()
torch, nn = try_import_torch()
parser = argparse.ArgumentParser()
parser.add_argument(
"--run", type=str, default="PPO", help="The RLlib-registered algorithm to use."
)
parser.add_argument(
"--framework",
choices=["tf", "tf2", "tfe", "torch"],
default="tf",
help="The DL framework specifier.",
)
parser.add_argument("--num-gpus", type=float, default=0.5)
parser.add_argument("--num-workers", type=int, default=1)
parser.add_argument("--num-gpus-per-worker", type=float, default=0.0)
parser.add_argument("--num-envs-per-worker", type=int, default=1)
parser.add_argument(
"--as-test",
action="store_true",
help="Whether this script should be run as a test: --stop-reward must "
"be achieved within --stop-timesteps AND --stop-iters.",
)
parser.add_argument(
"--stop-iters", type=int, default=50, help="Number of iterations to train."
)
parser.add_argument(
"--stop-timesteps", type=int, default=100000, help="Number of timesteps to train."
)
parser.add_argument(
"--stop-reward", type=float, default=180.0, help="Reward at which we stop training."
)
if __name__ == "__main__":
args = parser.parse_args()
ray.init(num_cpus=4)
# These configs have been tested on a p2.8xlarge machine (8 GPUs, 16 CPUs),
# where ray was started using only one of these GPUs:
# $ ray start --num-gpus=1 --head
# Note: A strange error could occur when using tf:
# "NotImplementedError: Cannot convert a symbolic Tensor
# (default_policy/cond/strided_slice:0) to a numpy array."
# In rllib/utils/exploration/random.py.
# Fix: Install numpy version 1.19.5.
# Tested arg combinations (4 tune trials will be setup; see
# tune.grid_search over 4 learning rates below):
# - num_gpus=0.5 (2 tune trials should run in parallel).
# - num_gpus=0.3 (3 tune trials should run in parallel).
# - num_gpus=0.25 (4 tune trials should run in parallel)
# - num_gpus=0.2 + num_gpus_per_worker=0.1 (1 worker) -> 0.3
# -> 3 tune trials should run in parallel.
# - num_gpus=0.2 + num_gpus_per_worker=0.1 (2 workers) -> 0.4
# -> 2 tune trials should run in parallel.
# - num_gpus=0.4 + num_gpus_per_worker=0.1 (2 workers) -> 0.6
# -> 1 tune trial should run in parallel.
config = {
# Setup the test env as one that requires a GPU, iff
# num_gpus_per_worker > 0.
"env": GPURequiringEnv if args.num_gpus_per_worker > 0.0 else "CartPole-v0",
# How many GPUs does the local worker (driver) need? For most algos,
# this is where the learning updates happen.
# Set this to > 1 for multi-GPU learning.
"num_gpus": args.num_gpus,
# How many RolloutWorkers (each with n environment copies:
# `num_envs_per_worker`)?
"num_workers": args.num_workers,
# How many GPUs does each RolloutWorker (`num_workers`) need?
"num_gpus_per_worker": args.num_gpus_per_worker,
# This setting should not really matter as it does not affect the
# number of GPUs reserved for each worker.
"num_envs_per_worker": args.num_envs_per_worker,
# 4 tune trials altogether.
"lr": tune.grid_search([0.005, 0.003, 0.001, 0.0001]),
"framework": args.framework,
}
stop = {
"training_iteration": args.stop_iters,
"timesteps_total": args.stop_timesteps,
"episode_reward_mean": args.stop_reward,
}
# Note: The above GPU settings should also work in case you are not
# running via tune.run(), but instead do:
# >> from ray.rllib.algorithms.ppo import PPO
# >> trainer = PPO(config=config)
# >> for _ in range(10):
# >> results = trainer.train()
# >> print(results)
results = tune.run(args.run, config=config, stop=stop)
if args.as_test:
check_learning_achieved(results, args.stop_reward)
ray.shutdown()