Orchestration for External Sim


I’m trying to utilize Ray’s distributed capabilities with RLLib. I’m using kubernetes for orchestration, and from what I’ve read, Ray creates a mini cluster underneath a kubernetes cluster within a single namespace.

My sim is actually external to my Gym Env, and I would like to keep it that way. In my step function to acquire the new state, I reach out to my sim via RPC calls. Ideally I’d have 3 services running: Gym Env, Sim, and an adapter between the env and the sim. I’m well acquainted with kubernetes, so my instinct is to create a kubernetes yaml for the orchestration between all of them, but with ray.init() and ray.tune(), I’m not sure how I can spin up multiple services when my environment spins up.

I feel like Ray should be able to handle that. Do I need to create a threaded Actor? I’ve found good information on RLLib and also Ray Core’s remote processing, but combining the two is giving me some trouble. Any advice will help!


Hi @gwisaacs2 ,
communicates to your remote environment to break out of the ray ecosystem.

Also, have a look at Sven’s post from last year to see an example of how you can interact with external environments: Reinforcement Learning with RLlib in the Unity Game Engine | by Sven Mika | Distributed Computing with Ray | Medium

The most favourable solution is one where you get external RPCs out of the picture. If that is not possible and your simulator is a clunky piece of software that you have to start by hand and then waits for incoming commands (such that it cannot be properly handled as a service by your cluster), you can also try to introduce a custom resource with ray. The custom resource would be symbolic for a 1-1 mapping from rollout workers to your remote environments. Then create your own gym-style env that requires your custom resource and have your rollout workers communicate to individual instances of your simulation.

Does this help? I am sorry there is not out of the box super easy solution to this. This might require a lot of legwork.

Maybe also have a look at ray/external_env.py at master · ray-project/ray · GitHub.