RLlib external environment example throws ValueError

YDenker · January 23, 2023, 10:20am

How severe does this issue affect your experience of using Ray?

Medium: It contributes to significant difficulty to complete my task, but I can work around it.

Hi! I am currently working on a project with the Gazebo Simulator and want to use RLlib to handle the reinforcement learning part.

I was currently looking into external environments and how i could create a wrapper for Gazebo. The example that is mentioned in the documentation (Environments — Ray 2.2.0) of the cartpole environment as an external environment however does not work and throws an Error.

I can start the cartpole_server.py just fine, but the cartpole_client.py throws the following error:

Env checking isn’t implemented for RemoteBaseEnvs, ExternalMultiAgentEnv, ExternalEnvs or environments that are Ray actors.
Traceback (most recent call last):
File “/home/ydenker/Repositories/pushing-robot/RLlib/cartpole_example_client.py”, line 81, in
client = PolicyClient(
File “/home/ydenker/.local/lib/python3.10/site-packages/ray/rllib/env/policy_client.py”, line 79, in init
self._setup_local_rollout_worker(update_interval)
File “/home/ydenker/.local/lib/python3.10/site-packages/ray/rllib/env/policy_client.py”, line 261, in _setup_local_rollout_worker
(self.rollout_worker, self.inference_thread) = _create_embedded_rollout_worker(
File “/home/ydenker/.local/lib/python3.10/site-packages/ray/rllib/env/policy_client.py”, line 405, in _create_embedded_rollout_worker
rollout_worker = RolloutWorker(**kwargs)
File “/home/ydenker/.local/lib/python3.10/site-packages/ray/rllib/evaluation/rollout_worker.py”, line 826, in init
self.sampler = SyncSampler(
File “/home/ydenker/.local/lib/python3.10/site-packages/ray/rllib/evaluation/sampler.py”, line 246, in init
self._env_runner_obj = EnvRunnerV2(
File “/home/ydenker/.local/lib/python3.10/site-packages/ray/rllib/evaluation/env_runner_v2.py”, line 236, in init
raise ValueError(
ValueError: Policies using the new Connector API do not support ExternalEnv.

Is there a quick fix for this? If i can’t get the example to work how am i suppose to create my own adapter class that is working? Thanks for help in advance.
Here are some more details about what i am using:
Ray version: 3.0.0.dev0 (commit: a830694359a272703aace4ac6f7e5f98b1d5d4a9)
OS: Ubuntu 22.04.1 LTS
Python version: Python 3.10.6

I have not edited the cartpole_client.py file in any way. It is an exact copy of:

github.com

ray-project/ray/blob/master/rllib/examples/serving/cartpole_client.py

#!/usr/bin/env python
"""
Example of running an external simulator (a simple CartPole env
in this case) against an RLlib policy server listening on one or more
HTTP-speaking port(s). See `cartpole_server.py` in this same directory for
how to start this server.

This script will only create one single env altogether to illustrate
that RLlib can run w/o needing an internalized environment.

Setup:
1) Start the policy server:
    See `cartpole_server.py` on how to do this.
2) Run this client:
    $ python cartpole_client.py --inference-mode=local|remote --[other options]
      Use --help for help.

In "local" inference-mode, the action computations are performed
inside the PolicyClient used in this script w/o sending an HTTP request
to the server. This reduces network communication overhead, but requires

This file has been truncated. show original

Please Help
Yannick

Lars_Simon_Zehnder · January 24, 2023, 7:23pm

Hi @YDenker, and welcome to the forum. I am running this on master and the example runs fine. Can you switch to master and check if you can reproduce?

YDenker · January 30, 2023, 11:04am

Hi @Lars_Simon_Zehnder thanks, happy to be here.
i currently have installed ray with rllib with the following command:
pip install https://s3-us-west-2.amazonaws.com/ray-wheels/master/a830694359a272703aace4ac6f7e5f98b1d5d4a9/ray-3.0.0.dev0-cp310-cp310-manylinux2014_x86_64.whl
If i am not mistaken this should be directly from the master branch or am i misunderstanding something.
I have tried to run it again today and got the same error.

Do you just have the repo cloned on your device and it works ?
I can try that as well.

Lars_Simon_Zehnder · January 30, 2023, 12:17pm

@YDenker, this is the master. Can you reinstall with the option --no-cache-dir and see, if this solves the problem?

Also, install the additional packages for RLlib via

python -m pip install -U --no-cache-dir "ray[rllib] @ https://s3-us-west-2.amazonaws.com/ray-wheels/master/a830694359a272703aace4ac6f7e5f98b1d5d4a9/ray-3.0.0.dev0-cp310-cp310-manylinux2014_x86_64.whl"

YDenker · January 31, 2023, 11:49am

@Lars_Simon_Zehnder i uninstalled and reinstalled using your command and the error persists.
I don’t really know what i am doing differently, if i am doing anything different at all.
The Error seems to revolves around “Env checking”:

‘Env checking isn’t implemented for RemoteBaseEnvs, ExternalMultiAgentEnv, ExternalEnvs or environments that are Ray actors.’

What exactly is Env checking and how can it not be supported if it works on your end?

The resulting error hints at the new Connector API not supporting what i’m planning to do:
‘ValueError: Policies using the new Connector API do not support ExternalEnv.’

Can i maybe circumvent the issue by using the old Connector API assuming there is such a thing?

Is the error even related to those at all and i’m just missing something crucial?

I’m not sure how to proceed from here. Any help is much appreciated.

Yannick