#ifdef

This was really helpful. I was trying to simulate connection failures locally and by applying these Apache config changes and issuing ‘touch tmp/stop.txt’, the app throws returns a 503.

Ah, but you will need to restart Apache, ’sudo apachectl graceful’.

… it’s possible to use mod_rewrite to prevent users from accessing your site during the deployment. Try this in your Apache virtual host configuration file:

[From Nodeta » Blog Archive » Stopping your Rails application with Phusion Passenger]