Nightly Maintenance and "Sorry Sites"

Servers need backups.  And, sometimes, there are nightly maintenance scripts that need to be run, for example dumping out all transactions, or importing orders or products.  Usually these maintenance tasks will be run from a cron job.

Often, these tasks impact the "production" website, or conversely, the "production" website often impacts these tasks.  Either way, sometimes it's best to get the site offline for a minute or two, to let the maintenance task run quickly and to completion, without competition.

I thought the approach below was totally obvious, but I've learned that a lot of people are really happy to learn how to do this sort of thing.

It's really straightforward for a cron job to also put a "Sorry Site" in place - a website that states "We're down for maintenance - please reload in a few minutes" or similar.   Here's a strategy for doing this.

Say your website document root is:

/var/www/website

And say your "sorry" website is:

/var/www/sorry

We'll make a script called /root/switch.

#!/bin/sh
site = /var/www/website
sorry = /var/www/sorry
hold = /var/www/hold
if [ -d /var/www/sorry ]; then
    mv $site $hold
    mv $sorry $site
else
    mv $site $sorry
    mb $hold $site
fi

Say your existing cron job is:

0 0 * * * /do/my/maintenance >/dev/null 2<&1

To put the sorry site in place while the maintenance is running, just change that to:

0 0 * * * /root/switch; /do/my/maintenance; /root/switch >/dev/null 2<&1

The above simply calls the "switch" script twice - once before, and once after, the maintenance script.  It keeps all of the details of what "switch" actually does hidden away from the cron job, as a good programming practice.

The above approach lets you customize your "sorry site" - some of the pages can say "We're down for maintenance" (say, the main page) and other pages can still work (say... for example... the pages that let people check out :-)

If you just want to take ALL pages offline, there's a simpler way - setup a variant .htaccess file and swap that in place, instead of moving the directories around.