ray/test/jenkins_tests/multi_node_tests/test_0.py

import os
import time

import ray


@ray.remote
def f():
  time.sleep(0.1)
  return ray.services.get_node_ip_address()


if __name__ == "__main__":
  ray.init(redis_address=os.environ["RAY_REDIS_ADDRESS"])
  # Check that tasks are scheduled on all nodes.
  num_attempts = 30
  for i in range(num_attempts):
    ip_addresses = ray.get([f.remote() for i in range(1000)])
    distinct_addresses = set(ip_addresses)
    counts = [ip_addresses.count(address) for address in distinct_addresses]
    print("Counts are {}".format(counts))
    if len(counts) == 5:
      break
  assert len(counts) == 5