Somethinghasgoneterriblywrong.com

January 24, 2011 9:35 PM

How can I find (or track) the downtime of the world's Top 100 websites?

SaaS geek, and I'm comparing 2010 performance; tracking 2011 performance.

posted by bamassippi to Computers & Internet (2 answers total)

netcraft will be your starting point. For example, uptime for www.facebook.com.

If you need to track this in real time, I dunno what they offer, but there's probably a way to politely scrape or download aggregate data if you look.
posted by dhartung at 10:02 PM on January 24, 2011

Keep in mind that "downtime" can be tricky to define for a large scale global web service. For example, is it downtime if the site is down only for customers of a certain ISP? What if it's a rural ISP that only serves 500 people? Or what if it's Comcast? Is it downtime if the site is only down for users whose email addresses start with the letter "j"? Is it downtime if things work for existing users, but new signups are broken? What about when 25% of requests are failing but the rest are working? Maybe it works for everyone except Android users. Or people who have the CSS cached already.

Any of those scenarios represent failures and, to some subset of users, reduced availability. If you limit yourself to only measuring when the site is totally down for everyone, you won't capture the true availability. However, the more granular information is both much harder to compare across services and also much harder to get (generally, only the company themselves will have the full picture, and even then often they don't -- monitoring and accounting for this kind of thing is hard).
posted by sharding at 10:47 PM on January 24, 2011 [1 favorite]