为什么cronjob多次执行

我的cronjob执行多次。
我的设置是否错误？
请帮我为什么cronjob多次执行

这是脚本

#!/bin/bash 
source /home/obe/env/bin/activate 
cd /home/obe/env/crawl/pjt/pjt 
scrapy crawl gets

这是我设置的crontab中，我使用centos7

* 23 * * * /home/obe/env/crawl/cron_set.sh

，而且我用ps aux | grep cron 我发现我的cronjob执行许多时间

root  1202 0.0 0.0 126336 288 ?  Ss 17:16 0:02 /usr/sbin/crond -n 
root  9870 0.0 0.0 113116  8 ?  Ss 23:00 0:00 /bin/bash /home/obe/env/clawer/cron_set.sh 
root  9908 0.0 0.0 113116  8 ?  Ss 23:01 0:00 /bin/bash /home/obe/env/clawer/cron_set.sh 
root  10203 0.0 0.0 113116  8 ?  Ss 23:09 0:00 /bin/bash /home/obe/env/clawer/cron_set.sh 
root  10238 0.0 0.0 113116  8 ?  Ss 23:10 0:00 /bin/bash /home/obe/env/clawer/cron_set.sh 
root  10269 0.0 0.0 113116  8 ?  Ss 23:11 0:00 /bin/bash /home/obe/env/clawer/cron_set.sh 
root  10328 0.0 0.0 113116  8 ?  Ss 23:13 0:00 /bin/bash /home/obe/env/clawer/cron_set.sh 
root  10370 0.0 0.0 113116  8 ?  Ss 23:14 0:00 /bin/bash /home/obe/env/clawer/cron_set.sh 
root  10412 0.0 0.0 113116  8 ?  Ss 23:15 0:00 /bin/bash /home/obe/env/clawer/cron_set.sh 
root  10455 0.0 0.0 113116  8 ?  Ss 23:16 0:00 /bin/bash /home/obe/env/clawer/cron_set.sh 
root  10594 0.0 0.0 113116  8 ?  Ss 23:17 0:00 /bin/bash /home/obe/env/clawer/cron_set.sh 
root  10631 0.0 0.0 113116  8 ?  Ss 23:18 0:00 /bin/bash /home/obe/env/clawer/cron_set.sh 
root  10660 0.0 0.0 113116  8 ?  Ss 23:19 0:00 /bin/bash /home/obe/env/clawer/cron_set.sh 
root  10699 0.0 0.0 113116  8 ?  Ss 23:20 0:00 /bin/bash /home/obe/env/clawer/cron_set.sh 
root  10731 0.0 0.0 113116  8 ?  Ss 23:21 0:00 /bin/bash /home/obe/env/clawer/cron_set.sh 
root  10753 0.0 0.0 113116  4 ?  Ss 23:22 0:00 /bin/bash /home/obe/env/clawer/cron_set.sh 
root  10779 0.0 0.0 113116 36 ?  Ss 23:23 0:00 /bin/bash /home/obe/env/clawer/cron_set.sh 
root 10802 0.5 0.0 112644 216 pts/2 S+ 23:23 0:00 grep --color=auto cron

为什么会发生这种情况？

来源

2015-10-12 user2492364