scrapy定时执行抓取任务

时间:2022-09-22 07:54:59

在ubuntu环境下,使用scrapy定时执行抓取任务,由于scrapy本身没有提供定时执行的功能,所以采用了crontab的方式进行定时执行:

1.首先编写脚本cron.sh 

【脚本基本知识:http://billie66.github.io/TLCL/book/zh/chap25.html】

#! /bin/sh

export PATH=$PATH:/usr/local/bin

cd /home/ubuntu/lecture/Lecture_crawler

nohup scrapy crawl jnuISAT > spider.log 2>&1 &
nohup scrapy crawl scutCS >> spider.log 2>&1 &
nohup scrapy crawl ScutSoftware >> spider.log 2>&1 &
nohup scrapy crawl tshIIIS >> spider.log 2>&1 &
nohup scrapy crawl SKLOIS >> spider.log 2>&1 &


2.下一步我们要做的事情是让我们的脚本可执行。使用 chmod 命令:
chmod 755 cron.sh 
权限为755的脚本,则每个人都能执行,和权限为700的 脚本,只有文件所有者能够执行

【此处可以自己运行一下脚本确保没有错误】

3.执行,crontab -e,规定crontab要执行的命令和要执行的时间频率

# Edit this file to introduce tasks to be run by cron.
#
# Each task to run has to be defined through a single line
# indicating with different fields when the task will be run
# and what command to run for the task
#
# To define the time you can provide concrete values for
# minute (m), hour (h), day of month (dom), month (mon),
# and day of week (dow) or use '*' in these fields (for 'any').#
# Notice that tasks will be started based on the cron's system
# daemon's notion of time and timezones.
#
# Output of the crontab jobs (including errors) is sent through
# email to the user the crontab file belongs to (unless redirected).
#
# For example, you can run a backup of all your user accounts
# at 5 a.m every week with:
# 0 5 * * 1 tar -zcf /var/backups/home.tgz /home/
#
# For more information see the manual pages of crontab(5) and cron(8)
#
# m h dom mon dow command
<span style="color: rgb(51, 51, 51); font-family: 华文楷体; font-size: 18px; line-height: 25.2px;">0 0 * * *</span> sh /home/ws/Documents/Lecture_crawler/cron.sh

【crontab的常见格式:】

每分钟执行  */1 * * * *

每小时执行     0 * * * *

每天执行        0 0 * * *

每周执行       0 0 * * 0

每月执行        0 0 1 * *

每年执行       0 0 1 1 *

scrapy定时执行抓取任务


4.通过/var/log/下面的crontab的日志验证生效
【注 日志默认不开启,可用过vi /etc/rsyslog.d/50-default.conf ,将cron.*这一行前的注释打开日志】

开启后运行tail –f  /var/log/cron.log

tail –f  /var/log/cron.log

scrapy定时执行抓取任务

参考文章:http://www.cnblogs.com/justinzhang/p/4500409.html