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scrapy-redis分布式

一、简介

  scrapy是一个基于redis的scrapy组件，用于快速实现scrapy项目的分布式数据爬取。

（一）安装redis

  • pip install scrapy_redis

（二）执行流程图

  • 调度器、管道不可以被分布式集群共享

二、中间件的使用

  • 下载中间件（Downloader Middleware）核心方法有3个

（一）设置headers和ip池

1、在middlewares里的MySpiderDownloaderMiddleware类属性中写入列表。

class MySpiderDownloaderMiddleware:
    def __init__(self):
        self.user_agent_list = [
            "Mozilla/5.0 (Linux; U; Android 2.3.6; en-us; Nexus S Build/GRK39F) AppleWebKit/533.1 (KHTML, like Gecko) Version/4.0 Mobile Safari/533.1",
            "Avant Browser/1.2.789rel1 (http://www.avantbrowser.com)",
            "Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US) AppleWebKit/532.5 (KHTML, like Gecko) Chrome/4.0.249.0 Safari/532.5",
            "Mozilla/5.0 (Windows; U; Windows NT 5.2; en-US) AppleWebKit/532.9 (KHTML, like Gecko) Chrome/5.0.310.0 Safari/532.9",
            "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US) AppleWebKit/534.7 (KHTML, like Gecko) Chrome/7.0.514.0 Safari/534.7",
            "Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US) AppleWebKit/534.14 (KHTML, like Gecko) Chrome/9.0.601.0 Safari/534.14",
            "Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US) AppleWebKit/534.14 (KHTML, like Gecko) Chrome/10.0.601.0 Safari/534.14",
            "Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US) AppleWebKit/534.20 (KHTML, like Gecko) Chrome/11.0.672.2 Safari/534.20",
            "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/534.27 (KHTML, like Gecko) Chrome/12.0.712.0 Safari/534.27",
            "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/535.1 (KHTML, like Gecko) Chrome/13.0.782.24 Safari/535.1",
            "Mozilla/5.0 (Windows NT 6.0) AppleWebKit/535.2 (KHTML, like Gecko) Chrome/15.0.874.120 Safari/535.2",
            "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/535.7 (KHTML, like Gecko) Chrome/16.0.912.36 Safari/535.7",
            "Mozilla/5.0 (Windows; U; Windows NT 6.0 x64; en-US; rv:1.9pre) Gecko/2008072421 Minefield/3.0.2pre",
            "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.0.10) Gecko/2009042316 Firefox/3.0.10",
            "Mozilla/5.0 (Windows; U; Windows NT 6.0; en-GB; rv:1.9.0.11) Gecko/2009060215 Firefox/3.0.11 (.NET CLR 3.5.30729)",
            "Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.9.1.6) Gecko/20091201 Firefox/3.5.6 GTB5",
            "Mozilla/5.0 (Windows; U; Windows NT 5.1; tr; rv:1.9.2.8) Gecko/20100722 Firefox/3.6.8 ( .NET CLR 3.5.30729; .NET4.0E)",
            "Mozilla/5.0 (Windows NT 6.1; rv:2.0.1) Gecko/20100101 Firefox/4.0.1",
            "Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:2.0.1) Gecko/20100101 Firefox/4.0.1",
            "Mozilla/5.0 (Windows NT 5.1; rv:5.0) Gecko/20100101 Firefox/5.0",
            "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:6.0a2) Gecko/20110622 Firefox/6.0a2",
            "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:7.0.1) Gecko/20100101 Firefox/7.0.1",
            "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:2.0b4pre) Gecko/20100815 Minefield/4.0b4pre",
            "Mozilla/4.0 (compatible; MSIE 5.5; Windows NT 5.0 )",
            "Mozilla/4.0 (compatible; MSIE 5.5; Windows 98; Win 9x 4.90)",
            "Mozilla/5.0 (Windows; U; Windows XP) Gecko MultiZilla/1.6.1.0a",
            "Mozilla/2.02E (Win95; U)",
            "Mozilla/3.01Gold (Win95; I)",
            "Mozilla/4.8 [en] (Windows NT 5.1; U)",
            "Mozilla/5.0 (Windows; U; Win98; en-US; rv:1.4) Gecko Netscape/7.1 (ax)",
            "HTC_Dream Mozilla/5.0 (Linux; U; Android 1.5; en-ca; Build/CUPCAKE) AppleWebKit/528.5  (KHTML, like Gecko) Version/3.1.2 Mobile Safari/525.20.1",
            "Mozilla/5.0 (hp-tablet; Linux; hpwOS/3.0.2; U; de-DE) AppleWebKit/534.6 (KHTML, like Gecko) wOSBrowser/234.40.1 Safari/534.6 TouchPad/1.0",
            "Mozilla/5.0 (Linux; U; Android 1.5; en-us; sdk Build/CUPCAKE) AppleWebkit/528.5  (KHTML, like Gecko) Version/3.1.2 Mobile Safari/525.20.1",
            "Mozilla/5.0 (Linux; U; Android 2.1; en-us; Nexus One Build/ERD62) AppleWebKit/530.17 (KHTML, like Gecko) Version/4.0 Mobile Safari/530.17",
            "Mozilla/5.0 (Linux; U; Android 2.2; en-us; Nexus One Build/FRF91) AppleWebKit/533.1 (KHTML, like Gecko) Version/4.0 Mobile Safari/533.1",
            "Mozilla/5.0 (Linux; U; Android 1.5; en-us; htc_bahamas Build/CRB17) AppleWebKit/528.5  (KHTML, like Gecko) Version/3.1.2 Mobile Safari/525.20.1",
            "Mozilla/5.0 (Linux; U; Android 2.1-update1; de-de; HTC Desire 1.19.161.5 Build/ERE27) AppleWebKit/530.17 (KHTML, like Gecko) Version/4.0 Mobile Safari/530.17",
            "Mozilla/5.0 (Linux; U; Android 2.2; en-us; Sprint APA9292KT Build/FRF91) AppleWebKit/533.1 (KHTML, like Gecko) Version/4.0 Mobile Safari/533.1",
            "Mozilla/5.0 (Linux; U; Android 1.5; de-ch; HTC Hero Build/CUPCAKE) AppleWebKit/528.5  (KHTML, like Gecko) Version/3.1.2 Mobile Safari/525.20.1",
            "Mozilla/5.0 (Linux; U; Android 2.2; en-us; ADR6300 Build/FRF91) AppleWebKit/533.1 (KHTML, like Gecko) Version/4.0 Mobile Safari/533.1",
            "Mozilla/5.0 (Linux; U; Android 2.1; en-us; HTC Legend Build/cupcake) AppleWebKit/530.17 (KHTML, like Gecko) Version/4.0 Mobile Safari/530.17",
            "Mozilla/5.0 (Linux; U; Android 1.5; de-de; HTC Magic Build/PLAT-RC33) AppleWebKit/528.5  (KHTML, like Gecko) Version/3.1.2 Mobile Safari/525.20.1 FirePHP/0.3",
            "Mozilla/5.0 (Linux; U; Android 1.6; en-us; HTC_TATTOO_A3288 Build/DRC79) AppleWebKit/528.5  (KHTML, like Gecko) Version/3.1.2 Mobile Safari/525.20.1",
            "Mozilla/5.0 (Linux; U; Android 1.0; en-us; dream) AppleWebKit/525.10  (KHTML, like Gecko) Version/3.0.4 Mobile Safari/523.12.2",
            "Mozilla/5.0 (Linux; U; Android 1.5; en-us; T-Mobile G1 Build/CRB43) AppleWebKit/528.5  (KHTML, like Gecko) Version/3.1.2 Mobile Safari 525.20.1",
            "Mozilla/5.0 (Linux; U; Android 1.5; en-gb; T-Mobile_G2_Touch Build/CUPCAKE) AppleWebKit/528.5  (KHTML, like Gecko) Version/3.1.2 Mobile Safari/525.20.1",
            "Mozilla/5.0 (Linux; U; Android 2.0; en-us; Droid Build/ESD20) AppleWebKit/530.17 (KHTML, like Gecko) Version/4.0 Mobile Safari/530.17",
            "Mozilla/5.0 (Linux; U; Android 2.2; en-us; Droid Build/FRG22D) AppleWebKit/533.1 (KHTML, like Gecko) Version/4.0 Mobile Safari/533.1",
            "Mozilla/5.0 (Linux; U; Android 2.0; en-us; Milestone Build/ SHOLS_U2_01.03.1) AppleWebKit/530.17 (KHTML, like Gecko) Version/4.0 Mobile Safari/530.17",
            "Mozilla/5.0 (Linux; U; Android 2.0.1; de-de; Milestone Build/SHOLS_U2_01.14.0) AppleWebKit/530.17 (KHTML, like Gecko) Version/4.0 Mobile Safari/530.17",
            "Mozilla/5.0 (Linux; U; Android 3.0; en-us; Xoom Build/HRI39) AppleWebKit/525.10  (KHTML, like Gecko) Version/3.0.4 Mobile Safari/523.12.2",
            "Mozilla/5.0 (Linux; U; Android 0.5; en-us) AppleWebKit/522  (KHTML, like Gecko) Safari/419.3",
            "Mozilla/5.0 (Linux; U; Android 1.1; en-gb; dream) AppleWebKit/525.10  (KHTML, like Gecko) Version/3.0.4 Mobile Safari/523.12.2",
            "Mozilla/5.0 (Linux; U; Android 2.0; en-us; Droid Build/ESD20) AppleWebKit/530.17 (KHTML, like Gecko) Version/4.0 Mobile Safari/530.17",
            "Mozilla/5.0 (Linux; U; Android 2.1; en-us; Nexus One Build/ERD62) AppleWebKit/530.17 (KHTML, like Gecko) Version/4.0 Mobile Safari/530.17",
            "Mozilla/5.0 (Linux; U; Android 2.2; en-us; Sprint APA9292KT Build/FRF91) AppleWebKit/533.1 (KHTML, like Gecko) Version/4.0 Mobile Safari/533.1",
            "Mozilla/5.0 (Linux; U; Android 2.2; en-us; ADR6300 Build/FRF91) AppleWebKit/533.1 (KHTML, like Gecko) Version/4.0 Mobile Safari/533.1",
            "Mozilla/5.0 (Linux; U; Android 2.2; en-ca; GT-P1000M Build/FROYO) AppleWebKit/533.1 (KHTML, like Gecko) Version/4.0 Mobile Safari/533.1",
            "Mozilla/5.0 (Linux; U; Android 3.0.1; fr-fr; A500 Build/HRI66) AppleWebKit/534.13 (KHTML, like Gecko) Version/4.0 Safari/534.13",
            "Mozilla/5.0 (Linux; U; Android 3.0; en-us; Xoom Build/HRI39) AppleWebKit/525.10  (KHTML, like Gecko) Version/3.0.4 Mobile Safari/523.12.2",
            "Mozilla/5.0 (Linux; U; Android 1.6; es-es; SonyEricssonX10i Build/R1FA016) AppleWebKit/528.5  (KHTML, like Gecko) Version/3.1.2 Mobile Safari/525.20.1",
            "Mozilla/5.0 (Linux; U; Android 1.6; en-us; SonyEricssonX10i Build/R1AA056) AppleWebKit/528.5  (KHTML, like Gecko) Version/3.1.2 Mobile Safari/525.20.1",
        ]
        self.http_ip = [
            "27.42.168.46:55481",
            "121.13.252.58:41564"
        ]
        self.https_ip = []

2、 运用random模块以随机形式在process_request(request, spider)下，将user-agent和ip池里的数据输出。

def process_request(self, request, spider):
    request.headers["User-Agent"] = random.choice(self.user_agent_list)

（二）设置response编码等信息

  • 一般保留原代码内容，可视情况在以下函数内改动。
  • process_response(request, response, spider)

（三）异常处理

  • process_exception(request, exception, spider)
  • 一般用于适配更改协议名，如：http或https。
def process_exception(self, request, exception, spider):
    if request.url.split(":")[0] == "http":
        request.meta["proxy"] = "http://" + random.choice(self.http_id)
    if request.url.split(":")[0] == "https":
        request.meta["proxy"] = "https://" + random.choice(self.https_id)

三、分布式爬虫实现流程

（一）开启redis服务

  • cd到安装路径，输入redis-server.exe redis.windows.conf
  • 如下：

  • 出现下图即为启动成功：

 （二）改写爬虫代码

1、在spider中导入RedisSpider模块

from scrapy_redis.spiders import RedisSpider

2、更改类继承

  • 将类继承改为RedisSpider

3、注释start_urls，添加redis_key = 健

（三）添加配置信息

  • 打开setting.py
  • 将以下信息添加到setting中。
# 1.启用调度将请求存储进redis
SCHEDULER = "scrapy_redis.scheduler.Scheduler"
# 2.确保所有spider通过redis共享相同的重复过滤。
DUPEFILTER_CLASS = "scrapy_redis.dupefilter.RFPDupeFilter"
# 可选 不清理redis队列，允许暂停/恢复抓取。 允许暂定,redis数据不丢失
SCHEDULER_PERSIST = True
# 3.指定连接到Redis时要使用的主机和端口。
REDIS_HOST = '127.0.0.1'
REDIS_PORT = 6379

（四）启动所有爬虫

  打开cmd启动redis-shell

  • cd 到根目录
  • 输入redis-cli.exe

当执行到这一步时，重新打开两个cmd窗口，cd到项目名，执行爬虫名进入监听状态

  • 输入lpush key url

    key: spider设置的redis_key（如：以上设置的键book）

    url : spider里面的start_urls（复制start_urls即可。）

    到这里，scrapy-redis伪分布式就启动成功了，但要注意，在每次启动redis后要记得清除缓存信息（指纹和队列数据），否则，下次执行还会按照上次的队列执行状态下运行。
  • 清除缓存队列信息的方法：flushall。在redis-cli.exe程序下输入此指令即可。

注意：若在无ua池和ip池的状态下运行时，尽快关闭，分布式爬取效率高、速度快的同时，也面临着封ip的风险。

四、分布式redis遇到的问题

  在数据爬取结束后，需要将redis的缓存数据进行清除，这时会发现两个问题：

  1、出现redis数据库连接错误的情况。

解决方法如下：

  方法一：修改本地配置文件redis.conf

  • 注释bind 127.0.0.1，默认的protected-mode yes设置为no，设置daemonize 为yes。
# bind 127.0.0.1 ::1
protected-mode no
daemonize yes

  具体设置可参考此链接的三步骤：https://www.cnblogs.com/LoLong/p/17183196.html

  方法二：卸载重装。

下面是安装和卸载Redis服务的命令，在redis-server.exe所在的目录下cmd执行下面命令即可：

安装redis服务：
            redis-server.exe --service-install redis.windows.conf --loglevel verbose 
 卸载redis服务：
            redis-server --service-uninstall

  方法三：重启电脑

  这个方法亲测有效！

  2、cmd到redis服务器失败。

  • Could not create server TCP listening socket（无法创建服务器TCP侦听套接字）。

解决方案：

  • 重启redis服务
  • 输入命令：redis-cli.exe 回车
  • 再输入 shutdown 回车
  • 再输入 exit 回车
  • 重新输入：redis-server.exe redis.windows.conf 启动成功

posted on 2022-12-06 19:43  乐之之  阅读(50)  评论(0)  编辑  收藏  举报