简单的 ray python 示例无法使其并行执行

Question

刚接触 ray，请耐心等待。我创建了以下示例来测试简单图像算法的光线和非光线实现之间的时间差异。为什么下面的代码不能并行执行？我可以在仪表板上看到所有内容都只加载给一名工人

import ray
import cv2
import numpy as np
import time

ray.init(ignore_reinit_error=True)


@ray.remote
class image_import(object):
    def __init__(self):
        pass

    def color(self):
        return cv2.imread("frame30.png", flags=0)

    def black(self):
        return cv2.imread("frame30.png", flags=0)

    def green(self):
        return cv2.imread("frame30.png", flags=0)

    def yellow(self):
        return cv2.imread("frame30.png", flags=0)

    def blue(self):
        return cv2.imread("frame30.png", flags=0)
    
    def orange(self):
        return cv2.imread("frame30.png", flags=0)
    
    def multiply_matrices_1(self,clr,b_1):
        return np.dot(clr,b_1)
    
    def multiply_matrices_2(self,b_2,b_3):
        return np.dot(b_2,b_3)
    
    def multiply_matrices_3(self,b_4,b_5):
        return np.dot(b_4,b_5)
    
    def multi_1(self,val_1,val_2):
        return np.dot(val_1,val_2)
    
    def multi_2(self,val_2):
        return np.dot(val_2,val_2)
        
    def multi_3(self,val_4,val_5):
        return np.dot(val_4,val_5)

start = time.time()
counter_actor = image_import.remote()

clr= counter_actor.color.remote()
b_1= counter_actor.black.remote()
b_2= counter_actor.green.remote()
b_3= counter_actor.yellow.remote()
b_4= counter_actor.blue.remote()
b_5= counter_actor.orange.remote()


multi_1= counter_actor.multiply_matrices_1.remote(clr,b_1)
multi_2= counter_actor.multiply_matrices_2.remote(b_2,b_3)
multi_3= counter_actor.multiply_matrices_3.remote(b_3,b_4)

multi_4= counter_actor.multi_1.remote(multi_1,multi_2)
multi_5= counter_actor.multi_2.remote(multi_3)

addition= counter_actor.multi_3.remote(multi_4,multi_5)

results= ray.get(addition)
duration = time.time() - start
print(duration)

Answer 1

您正在创建一个 actor（您 class 的远程对象），并且 actor 任务是串行执行的：

https://docs.ray.io/en/master/walkthrough.html#calling-the-actor

对于并行执行，只需去掉 class:

@ray.remote
def color(self):
    return cv2.imread("frame30.png", flags=0)

@ray.remote
def black(self):
    return cv2.imread("frame30.png", flags=0)

futures = [color.remote(), black.remote()]  # Will execute in parallel
ray.get(futures)