YouTube and others are putting up a nice looking message page while they are doing a release or maintenance. I'm wondering what's the best way of redirecting all requests to this "Sorry we're temporarily down" page.
Would you modify the VirtualHost entry in Apache's httpd.conf?
Would you change the DNS entry?
Any other ideas?
The technique should ideally be easy to turn on and off.
If your home page doesn't involve dynamic content (and even if it does, but you aren't touching those parts of it), keep your home page up.
If you aren't taking down your DB, keep the user sign-up up.
When someone tries to log-in, then display the message.
Keep your roll-out window to under 30 mins if at all possible (rolling out features in smaller batches makes this easier).