如何在不杀死运行php的情况下使站点脱机进行维护从http端开始？

I wrote a script upload_songs.php

When executed from the command line

$ php upload_songs.php

I can take the site offline

$ a2dissite my_website
$ service apache2 reload

and upload_songs.php will continue to run

However when I execute upload_songs.php from the http side by going to my_website.com/upload_songs.php if I do the following

$ a2dissite my_website
$ service apache2 reload

The php process upload_songs.php gets killed. How can I take the site offline for maintenance without killing running php processes that have been started from the http side?

apachectl graceful

This will wait until all connections are closed before restarting apache.

Docs for apachectl http://httpd.apache.org/docs/2.2/programs/apachectl.html