[GitHub] [beam] drfloob commented on issue #22533: [Bug]: grpcio==1.48.0 causes Java expansion service to hang on startup in Python XLang pipelines.

[GitBox <gi...@apache.org>]

drfloob commented on issue #22533:
URL: https://github.com/apache/beam/issues/22533#issuecomment-1209881902

   @chamikaramj I believe you're running into a deadlock with Popen using `stdout=subprocess.PIPE`. I confirmed that the gRPC fork handlers aren't running at all when your example hangs, which means this isn't likely a threading issue. And by changing that one line in subprocess_server.py to `subprocess.Popen(cmd, stdout=None, stderr=None)`, Popen no longer hangs. Please try reproducing my results.
   
   I'm not sure what would have changed in python 1.48 to precipitate this, but presumably: more stdout/stderr than there was in v1.47. 
   
   See https://docs.python.org/3.8/library/subprocess.html#subprocess.Popen


-- 
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

To unsubscribe, e-mail: github-unsubscribe@beam.apache.org

For queries about this service, please contact Infrastructure at:
users@infra.apache.org