restart apache service automatically using cron 12AM daily

问题

I have a CentOs setup in test server.

I wanna to run a cron job (the cron needs to run apache server at 12AM) daily.

My cron.daily fodler is located in /etc/cron.daily

Please let me know the steps how to implement this.

Usually I use to restart the apache service using the below command:

service httpd restart

I wanna to do restart apache service automatically using cron 12AM daily.

Thanks in advance.

回答1:

While @einterview's answer is almost correct, it's important to note that a * in the minute column will run the job every minute of that hour. If intending to run once every hour, steps would be:

1. SSH into server.

2. Get list of current user's jobs with $ crontab -l

3. Edit jobs list with $ crontab -e (default editor will open)

4. Add 0 4 * * * service mysql restart for mysql at 4:00am

5. Add 0 5 * * * service apache2 restart for apache2 at 5:00am

6. Add 0 0 * * * service apache2 restart for apache2 at 12:00 am

7. Save and close (Ctrl+O and Ctrl+X in nano)

8. Recheck with $ crontab -l

回答2:

I got it and give you step by step adding cron jobs into your system:

1. Login to your server with SSH
2. Type crontab -l to display list of cron jobs,
3. Type crontab -e to edit your crontab,
4. Add 0 4 * * * /etc/init.d/mysqld restart to restart Mysql everyday at 4 AM,
5. Add 0 5 * * * /etc/init.d/httpd restart to restart Apache everyday at 5 AM and
6. Add 0 24 * * * /etc/init.d/httpd restart to restart Apache everyday at 12 AM
7. Save your file,
8. Recheck with crontab -l

回答3:

I am not allowed to comment yet on the last one here, but actually you can just use 0 0 * * * then it will go through a-ok.

回答4:

following this advice adding: 0 12 * * * /etc/init.d/httpd restart 0 24 * * * /etc/init.d/httpd restart

I get "/tmp/crontab.D6cOzs/crontab":3: bad hour errors in crontab file, can't install. i had to do 12 only then it worked, so I'm assuming 24 is unacceptable

来源：https://stackoverflow.com/questions/28498400/restart-apache-service-automatically-using-cron-12am-daily