python负载均衡的简单实现方法

#!/usr/bin/python
# -*- coding: utf-8 -*-
import requests
import random
import os
import sys
import time
import ConnectionError
import Module_bException
module_b = "10.10.10.115:10081,10.10.10.115:10082,10.10.10.115:10083,10.10.10.115:10084"
class Module_b():
  def __init__(self):
    self.url_prefix = [val.strip() for val in module_b.split(',')]
  def _request(self, short_uri, payload):
    res = None
    try_count = 1
    url_prefixs = self.url_prefix[:]
    url_prefixs.sort(key=lambda f: random.randint(0, 100))
　　　　　　
    for curr_url_prefix in url_prefixs:
      url = os.path.join(curr_url_prefix, short_uri)
      try:
        res = requests.post(url, data=payload)
        break
      except ConnectionError as e:
        try_count += 1
        sys.stderr.write('can not connect to Module_b, retry ...\n')
        time.sleep(1)
        if try_count == len(url_prefixs):
          raise e
    if res.status_code != 200:
      raise Module_bException('HTTP ERROR: %s' % res.text)
    result = res.json()
    if result['status'] != '0':
      raise Module_bException(result['errstr'])
    return result['result']