ray/rllib/examples/remote_vector_env_with_custom_api.py

139 lines
4.4 KiB
Python

"""
This script demonstrates how one can specify custom env APIs in
combination with RLlib's `remote_worker_envs` setting, which
parallelizes individual sub-envs within a vector env by making each
one a ray Actor.
You can access your Env's API via a custom callback as shown below.
"""
import argparse
import gym
import os
import ray
from ray.rllib.agents.callbacks import DefaultCallbacks
from ray.rllib.env.apis.task_settable_env import TaskSettableEnv
from ray.rllib.utils.test_utils import check_learning_achieved
from ray import tune
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-workers", type=int, default=1)
# This should be >1, otherwise, remote envs make no sense.
parser.add_argument("--num-envs-per-worker", type=int, default=4)
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.")
class NonVectorizedEnvToBeVectorizedIntoRemoteVectorEnv(TaskSettableEnv):
"""Class for a single sub-env to be vectorized into RemoteVectorEnv.
If you specify this class directly under the "env" config key, RLlib
will auto-wrap
Note that you may implement your own custom APIs. Here, we demonstrate
using RLlib's TaskSettableEnv API (which is a simple sub-class
of gym.Env).
"""
def __init__(self, config):
self.action_space = gym.spaces.Box(0, 1, shape=(1, ))
self.observation_space = gym.spaces.Box(0, 1, shape=(2, ))
self.task = 1
def reset(self):
self.steps = 0
return self.observation_space.sample()
def step(self, action):
self.steps += 1
return self.observation_space.sample(), 0, self.steps > 10, {}
def set_task(self, task) -> None:
"""We can set the task of each sub-env (ray actor)"""
print("Task set to {}".format(task))
self.task = task
class TaskSettingCallback(DefaultCallbacks):
"""Custom callback to verify, we can set the task on each remote sub-env.
"""
def on_train_result(self, *, trainer, result: dict, **kwargs) -> None:
""" Curriculum learning as seen in Ray docs """
if result["episode_reward_mean"] > 0.0:
phase = 0
else:
phase = 1
# Sub-envs are now ray.actor.ActorHandles, so we have to add
# `remote()` here.
trainer.workers.foreach_env(lambda env: env.set_task.remote(phase))
if __name__ == "__main__":
args = parser.parse_args()
ray.init(num_cpus=6)
config = {
# Specify your custom (single, non-vectorized) env directly as a
# class. This way, RLlib can auto-create Actors from this class
# and handle everything correctly.
# TODO: Test for multi-agent case.
"env": NonVectorizedEnvToBeVectorizedIntoRemoteVectorEnv,
# Set up our own callbacks.
"callbacks": TaskSettingCallback,
# Force sub-envs to be ray.actor.ActorHandles, so we can step
# through them in parallel.
"remote_worker_envs": True,
# How many RolloutWorkers (each with n environment copies:
# `num_envs_per_worker`)?
"num_workers": args.num_workers,
# 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,
# Use GPUs iff `RLLIB_NUM_GPUS` env var set to > 0.
"num_gpus": int(os.environ.get("RLLIB_NUM_GPUS", "0")),
"framework": args.framework,
}
stop = {
"training_iteration": args.stop_iters,
"timesteps_total": args.stop_timesteps,
"episode_reward_mean": args.stop_reward,
}
results = tune.run(args.run, config=config, stop=stop, verbose=1)
if args.as_test:
check_learning_achieved(results, args.stop_reward)
ray.shutdown()