【標題】
python分佈式計算框架PP(Parallel Python)集羣模式試用
【背景】
Parallel Python庫（簡稱PP）
網上的教程都是單機多進程測試，決定試試集羣分佈式計算效果
【結論】
用了兩臺物理機，一個4核，一個2核，集羣分佈式計算
可以看到最終加速比爲5.1，計算方法是（60+27）/17=5.1。相當於5.1個CPU核心，比較充分地利用了多個計算機的多個CPU
【操作過程】
配置教程如下：
http://www.parallelpython.com/content/view/15/30/#QUICKCLUSTERS
計算子節點上，需要安裝python，並安裝pp庫，
pip install pp 即可安裝pp庫
安裝完成後，會有一個 ppserver.py在 scripts目錄中
python ppserver.py -p 35000 -i 192.168.1.104 -s "123456"
該命令讓計算子結點啓動一個35000端口監聽，密碼是123456，自己的IP是192.168.1.104
主結點中創建ppserver實例時，需要指定ip列表，和secret，與之配合。
主結點運行任務時，可以動態負載均衡方式，發送任務給子結點
試用了官方提供的第一個demo，
http://www.parallelpython.com/content/view/17/31/
並將測試數據改大一些，用了兩臺物理機，一個4核，一個2核，集羣分佈式計算
可以看到最終加速比爲5.1，計算方法是（60+27）/17=5.1。相當於5.1個CPU核心，比較充分地利用了多個計算機的多個CPU
#!/usr/bin/python
# File: sum_primes.py
# Author: VItalii Vanovschi
# Desc: This program demonstrates parallel computations with pp module
# It calculates the sum of prime numbers below a given integer in parallel
# Parallel Python Software: http://www.parallelpython.com
import math, sys, time, datetime
import pp
def isprime(n):
"""Returns True if n is prime and False otherwise"""
if not isinstance(n, int):
raise TypeError("argument passed to is_prime is not of 'int' type")
if n < 2:
return False
if n == 2:
return True
max = int(math.ceil(math.sqrt(n)))
i = 2
while i <= max:
if n % i == 0:
return False
i += 1
return True
def sum_primes(n):
"""Calculates sum of all primes below given integer n"""
return sum([x for x in xrange(2,n) if isprime(x)])
print """Usage: python sum_primes.py [ncpus]
[ncpus] - the number of workers to run in parallel,
if omitted it will be set to the number of processors in the system
"""
# tuple of all parallel python servers to connect with
#ppservers = ()
ppservers = ("192.168.1.104:35000",)
#ppservers=("*",)
if len(sys.argv) > 1:
ncpus = int(sys.argv[1])
# Creates jobserver with ncpus workers
job_server = pp.Server(ncpus, ppservers=ppservers, secret="123456")
else:
# Creates jobserver with automatically detected number of workers
job_server = pp.Server(ppservers=ppservers, secret="123456")
print "Starting pp with", job_server.get_ncpus(), "workers"
# Submit a job of calulating sum_primes(100) for execution.
# sum_primes - the function
# (100,) - tuple with arguments for sum_primes
# (isprime,) - tuple with functions on which function sum_primes depends
# ("math",) - tuple with module names which must be imported before sum_primes execution
# Execution starts as soon as one of the workers will become available
job1 = job_server.submit(sum_primes, (100,), (isprime,), ("math",))
# Retrieves the result calculated by job1
# The value of job1() is the same as sum_primes(100)
# If the job has not been finished yet, execution will wait here until result is available
result = job1()
print "Sum of primes below 100 is", result
start_time = time.time()
# The following submits 8 jobs and then retrieves the results
inputs = (500000, 500100, 500200, 500300, 500400, 500500, 500600, 500700, 500000, 500100, 500200, 500300, 500400, 500500, 500600, 500700)
#inputs = (1000000, 1000100, 1000200, 1000300, 1000400, 1000500, 1000600, 1000700)
jobs = [(input, job_server.submit(sum_primes,(input,), (isprime,), ("math",))) for input in inputs]
for input, job in jobs:
print datetime.datetime.now()
print "Sum of primes below", input, "is", job()
print "Time elapsed: ", time.time() - start_time, "s"
job_server.print_stats()
運行結果：
c:\Python27\python.exe test_pp_official.py
Usage: python sum_primes.py [ncpus]
[ncpus] - the number of workers to run in parallel,
if omitted it will be set to the number of processors in the system
Starting pp with 4 workers
Sum of primes below 100 is 1060
2016-08-28 19:07:26.579000
Sum of primes below 500000 is 9914236195
2016-08-28 19:07:33.032000
Sum of primes below 500100 is 9917236483
2016-08-28 19:07:33.035000
Sum of primes below 500200 is 9922237979
2016-08-28 19:07:33.296000
Sum of primes below 500300 is 9926740220
2016-08-28 19:07:33.552000
Sum of primes below 500400 is 9930743046
2016-08-28 19:07:33.821000
Sum of primes below 500500 is 9934746636
2016-08-28 19:07:34.061000
Sum of primes below 500600 is 9938250425
2016-08-28 19:07:37.199000
Sum of primes below 500700 is 9941254397
2016-08-28 19:07:37.202000
Sum of primes below 500000 is 9914236195
2016-08-28 19:07:41.640000
Sum of primes below 500100 is 9917236483
2016-08-28 19:07:41.742000
Sum of primes below 500200 is 9922237979
2016-08-28 19:07:41.746000
Sum of primes below 500300 is 9926740220
2016-08-28 19:07:41.749000
Sum of primes below 500400 is 9930743046
2016-08-28 19:07:41.752000
Sum of primes below 500500 is 9934746636
2016-08-28 19:07:41.756000
Sum of primes below 500600 is 9938250425
2016-08-28 19:07:43.846000
Sum of primes below 500700 is 9941254397
Time elapsed: 17.2770001888 s
Job execution statistics:
job count | % of all jobs | job time sum | time per job | job server
6 | 35.29 | 27.4460 | 4.574333 | 192.168.1.104:35000
11 | 64.71 | 60.2950 | 5.481364 | local
Time elapsed since server creation 17.2849998474
0 active tasks, 4 cores
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版權聲明：本文爲CSDN博主「delacrxoix_xu」的原創文章，遵循 CC 4.0 BY-SA 版權協議，轉載請附上原文出處鏈接及本聲明。
原文鏈接：https://blog.csdn.net/delacroix_xu/article/details/52347391
