reuse_actor.py

import ray
from ray.util.placement_group import placement_group, remove_placement_group
import time

NUM_TRIALS = 100

@ray.remote
class Actor:
    def __init__(self, *args):
        if len(args) > 0:
            self._val = args[0]
        else:
            self._val = 0
    def set_val(self, val):
        self._val = val
    def get_val(self):
        return self._val

@ray.remote
def task():
    return 2

ray.init()

results = []
start = time.perf_counter()
pg = placement_group([{"CPU": 1}])
actor = Actor.options(placement_group=pg).remote()
for i in range(NUM_TRIALS):
    actor.set_val.remote(i)
    results.append(ray.get(actor.get_val.remote()))
remove_placement_group(pg)
taken = time.perf_counter() - start

print(f"Reuse actor. Took {taken:.2f} seconds")

results = []
start = time.perf_counter()
for i in range(NUM_TRIALS):
    pg = placement_group([{"CPU": 1}])
    actor = Actor.options(placement_group=pg).remote(i)
    results.append(ray.get(actor.get_val.remote()))
    remove_placement_group(pg)
taken = time.perf_counter() - start

print(f"New actor. Took {taken:.2f} seconds")