You have to manually start Apache web server every time you do reboot the server. You want the Apache web service to start automatically.
1. Edit /etc/crontab. Add the lowest line of these two (the line above is for reference):
# * * * * * user-name command to be executed
@reboot root apachectl start
2. Save the changes. You are done.
This solution only works if you are doing a warm (or soft) reboot. A start up from a turned-off machine will not have the Apache web service running because of this crontab entry. A crontab would not be needed if your solution could allow the Apache web service to start automatically after a cold (or hard) boot up and a warm (or soft) reboot. For a solution like this, see this link.