[Bug] Unable to Schedule Fractional CPUs on Windows 10

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• I searched the issues and found no similar issues.

Ray Component

Ray Core

What happened + What you expected to happen

The Problem:

With enough available resources (i.e. 12 CPUs), Actor number 13 is always pending regardless of the fractional CPU assigned to it. Then after that, most Actors keep pending.

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Resources

Resources Status during Actors Creation (12 Logical CPUs / 6 Physical Cores, 32GB RAM):

Versions / Dependencies

Ray version 1.9.0

Redis version 4.0.2

Reproduction script

  import time
  import ray
  
  @ray.remote(num_cpus=0.01)  # tried different values
  class Actor:
      def __init__(self):
          pass
  
  if __name__ == '__main__':
      try:
          ray.init(num_cpus=12)  # tried different values
          time.sleep(30)
          for i in range(50):
              Actor.options(name=str(i + 1), lifetime="detached").remote()
              time.sleep(10)
      except Exception as e:
          print("Exception {} ".format(str(e)))
      finally:
          ray.shutdown()

Anything else

No response

Are you willing to submit a PR?

• Yes I am willing to submit a PR!

[pcmoritz]

That’s awesome! Thanks for your help resolving this (and reporting it!).

Yes it will be part of the 1.10 release. In 1.10 we will likely declare single node Ray core on Windows stable, I actually think that https://github.com/ray-project/ray/pull/20986 was the last big bug of Ray core on Windows given that many tests started passing after it was merged (fingers crossed). There are some components that need more work (like runtime environments) that are not used by default and we will address those in Q1 of 2021.

I’m going to go ahead and close this issue, @czgdp1807 can you open a separate one for the investigation about the warning for users if actors are waiting to be scheduled for an extended period of time due to lack of resources?

[John-Almardeny]

https://s3-us-west-2.amazonaws.com/ray-wheels/master/4dcba1d0f43880bf22297f1bc9478930b85038ac/ray-2.0.0.dev0-cp39-cp39-win_amd64.whl

Cheers. Totally forget about it. I spent my development life in Ubuntu. Just switched to Windows recently!