基于广域网的主从分布式爬虫系统

本文主要是介绍基于广域网的主从分布式爬虫系统，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

目的：构造基于广域网的主从分布式爬虫系统，以asp300网站为例，主机用来爬取任务地址，从机在每次任务完成会向主机发送任务请求，由主机分配任务。

原理：

整个爬虫系统分为两块，一块是主机，一块是从机，从机数量不限，视主机的瓶颈压力而定！主机一般只用一台，但如果性能不够或者达到性能瓶颈，那主机就成了限制整个爬虫系统的最大效率的瓶颈，这也就是所谓的“木桶效应”。

如何提高主机效率在本篇文章中不做研究，大家自行探索。

实现工具：

语言：Python

  网址：ASP300.COM

环境：腾讯云学生主机（配置：1GHZ   单核   1G内存）

代码示例：

主机代码：

#coding=gb2312
import urllib2
import urllib
import random
import socket
from bs4 import BeautifulSoup
user_agent = ["User-Agent,Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/56.0.2924.87 Safari/537.36","User-Agent,Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10_6_8; en-us) AppleWebKit/534.50 (KHTML, like Gecko) Version/5.1 Safari/534.50","User-Agent,Mozilla/5.0 (Windows; U; Windows NT 6.1; en-us) AppleWebKit/534.50 (KHTML, like Gecko) Version/5.1 Safari/534.50","User-Agent,Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; Trident/5.0;","User-Agent,Mozilla/5.0 (Windows NT 6.1; rv,2.0.1) Gecko/20100101 Firefox/4.0.1","User-Agent,Opera/9.80 (Windows NT 6.1; U; en) Presto/2.8.131 Version/11.11","User-Agent, Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; 360SE)"]def iteration():url_list = []for i in range(1, 100):url = 'http://www.asp300.com/SoftList/27/27_%d.html' % i# 伪造用户身份headers = {'User-Agent': user_agent[random.randint(0, 6)]}  # 随机headersreq = urllib2.Request(url=url, headers=headers)#测试页面是否能丢失try:response = urllib2.urlopen(req)except urllib2.URLError, e:if hasattr(e, 'code') and e.code == 404:continueurl_list.append(url)return url_listdef server(url_list):HOST = ''PORT = 21567BUFSIZ = 1024ADDR = (HOST,PORT)#创建套接字tcpSerSock = socket.socket(socket.AF_INET,socket.SOCK_STREAM)tcpSerSock.bind(ADDR)tcpSerSock.listen(5)while True:#死循环，使主机保持接受从机访问print 'waiting for connection......'tcpCliSock, addr = tcpSerSock.accept()print '...connected from:',addrwhile True:data = tcpCliSock.recv(BUFSIZ)if not data:break#发送任务到从机tcpCliSock.send('%s'%url_list.pop)tcpCliSock.close()tcpSerSock.close()if __name__ == 'main':url_list = iteration()server(url_list)

从机代码：

#coding=gb2312
import urllib2
import urllib
import cookielib
import re
from PIL import Image
from bs4 import BeautifulSoup
import socket
import timeclass MyError(Exception):#定义一个错误，留引发passclass IgnoError(Exception):#定义一个错误，留引发passclass RedirctHandler(urllib2.HTTPRedirectHandler):#重构302,301页面处理类"""docstring for RedirctHandler"""def http_error_301(self, req, fp, code, msg, headers):if 'location' in headers:newurl = headers.getheaders('location')[0]elif 'uri' in headers:newurl = headers.getheaders('uri')[0]else:returnreturn newurldef http_error_302(self, req, fp, code, msg, headers):if 'location' in headers:newurl = headers.getheaders('location')[0]elif 'uri' in headers:newurl = headers.getheaders('uri')[0]else:returnreturn newurldef Download(url,headers,num_retries=9):#下载url所指向的页面req = urllib2.Request(url, headers=headers)try:response = urllib2.urlopen(req,timeout=60)the_page = response.read()response.close()except urllib2.URLError,e:if num_retries > 0 and hasattr(e,'code') and (500 <= e.code <600):return Download(url,headers,num_retries - 1)elif hasattr(e, 'code') and (e.code == 404):raise IgnoErrorelse:print 'Download Error:', e.reasonraise MyErrorexcept socket.timeout:if num_retries > 0 :return Download(url, headers, num_retries - 1)raise socket.timeoutreturn the_pagedef resolve(html):#提取源码信息image_url = []soup = BeautifulSoup(html,"lxml")title = unicode(soup.head.title.string)title = re.search('(.*?)_ASP300',title).groups()[0]size = soup.find('div',class_='box').find('div',class_='box_1').find('div',id='goodsInfo').find('div',class_='textInfo').ul.find_all('li')[2].ddsize = unicode(size)size = float(re.search(u'软件大小：(.*?)\D',size).groups()[0])summary_tag = soup.find('div',class_='s')summary_content = unicode(summary_tag).strip()summary_content = summary_content.split('<br/>')summary_content[0] = summary_content[0][15:]del summary_content[len(summary_content)-1]for a,b in enumerate(summary_content):if b == '\n':del summary_content[a]summary_cahe = u''for c in summary_content:summary_cahe += (c + u'<br/>')summary_content = summary_cahefor i in summary_tag.p.find_all('img'):image_url.append('http://www.asp300.com' + i['src'])#获取图片下载地址，放入image_url中,image_url中的元素为str，非unicodereturn title,size,summary_content,image_url#title,summary是unicode，size是float，image_url中的元素均为strdef download_image(name,url,headers,num_tries=9):#下载图片req = urllib2.Request(url=url,headers=headers)try:f = urllib2.urlopen(req,timeout=60)except urllib2.URLError, e:if num_tries > 0 and hasattr(e,'code') and 500 <= e.code <600:return download_image(name,url,headers,num_tries - 1)else:print '下载图片出错：',e.reasonraise MyErrorexcept socket.timeout:if num_tries > 0 :return download_image(name,url,headers,num_tries - 1)raise socket.timeoutimage = open(name,'wb')image.write(f.read())f.close()image.close()def screenshot(name,change,format):# 去除水印im = Image.open(name)w,h = im.sizebox = (0,0,w,h-change)region = im.crop(box)region.save(name,format)def soft_url(url,headers,num_retries=9):#获取软件真实下载地址id = int(re.search('SoftView_(.*?).html',url).groups()[0])url1 = 'http://www.asp300.com/2012dll/Down.jsp?CodeID=%d&id=1'%id#这一步是为了获取商品的ookiecookie = cookielib.CookieJar()handler = urllib2.HTTPCookieProcessor(cookie)opener1 = urllib2.build_opener(handler)req1 = urllib2.Request(url=url1,headers=headers)try:opener1.open(req1,timeout=60)print '%s：获取下载COOKIE成功'%time.ctime()except urllib2.URLError, e:if num_retries > 0 and hasattr(e,'code') and (500 <= e.code <600):return soft_url(url,headers,num_retries - 1)else:print 'SOFT_URL1 Error:', e.reasonraise MyErrorexcept socket.timeout:if num_retries > 0:return soft_url(url, headers, num_retries - 1)raise socket.timeout#cookie获取完毕#这一步是基于上一步的cookie，获取真是下载地址#debug_handler = urllib2.HTTPHandler(debuglevel=1)opener2 = urllib2.build_opener(RedirctHandler,handler)url2 = 'http://www.asp300.com/2012dll/DownBJ.jsp?CodeID=%d'%idreq2 = urllib2.Request(url=url2,headers=headers)try:html = opener2.open(req2,timeout=60)print '%s：获取下载地址成功'%time.ctime()except urllib2.URLError, e:if num_retries > 0 and hasattr(e,'code') and (500 <= e.code <600):return soft_url(url,headers,num_retries - 1)else:print 'SOFT_URL2 Error:', e.reasonraise MyErrorexcept socket.timeout:if num_retries > 0:return soft_url(url, headers, num_retries - 1)raise socket.timeoutreturn htmldef clicent():HOST = ''#这里填主机ip，自己根据情况修改PORT = 21567#这里填主机端口，自己根据情况修改BUFSIZ = 1024ADDR = (HOST,PORT)#创建套接字tcpCliSock = socket.socket(socket.AF_INET,socket.SOCK_STREAM)tcpCliSock.connect(ADDR)data = "ask for task"tcpCliSock.send(data)data = tcpCliSock.recv(BUFSIZ)return datadef main():headers = {'User-Agent': 'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/39.0.2171.95 '}url = clicent()html = Download(url, headers)print '页面下载完成'title, size, summary_content, image_url = resolve(html)print '信息提取完成'id = 0for i in image_url:name = './image/image_cache%d.jpg' % iddownload_image(name, i, headers)print '图片下载完成%d' % idscreenshot(name, 52, 'jpeg')print '图片转换完成'id += 1download_url = soft_url(url, headers)print titleprint sizesummary_content = summary_content.replace(u'\u200b',u'')#unicode特殊字符'\u200b'，不能转为gb2312print summary_content,type(summary_content)print summary_content.encode('gb2312')print image_urlprint download_urlif __name__ == '__main__':main()

这篇关于基于广域网的主从分布式爬虫系统的文章就介绍到这儿，希望我们推荐的文章对编程师们有所帮助！

---