The headline of this Gigaom post was what first caught my eye--"Five Nines on the Net is a Pipe Dream". Not really going out on a limb with that one. But the post goes on to link to a NYT article that features the website downforeveryoneorjustme.com. Downforeveryoneorjustme seeks to answer the eponymous question for any website whose URL you type into its simple, Google-style interface. Can't get to Amazon or wherever? Type the URL in and learn whether that website is actually down, or if the issue is on your end of things.
The headline of this Gigaom post was what first caught my eye--"Five Nines on the Net is a Pipe Dream". Not really going out on a limb with that one. But the post goes on to link to a NYT article that features the website downforeveryoneorjustme.com. Downforeveryoneorjustme seeks to answer the eponymous question for any website whose URL you type into its simple, Google-style interface. Can't get to Amazon or wherever? Type the URL in and learn whether that website is actually down, or if the issue is on your end of things.The obvious question when you use the site is, how does it know? I couldn't find an explanation anywhere, but I did find the personal website of downforeveryoneorjustme's creator, Alex Payne. Alex works for Twitter but he emphasized in emails to me that he developed and runs downforeveryoneorjustme as a personal side project unconnected to Twitter, and he was speaking as an individual, not a Twitter employee. Here's what he wrote me about how the site learns the answer to its question:
The site is as dead-simple as it gets: it makes an HTTP HEAD request to the root ("/") of the user-provided domain. If I get a response code in the 200/300 series, I assume the site is up. If I get a 500 or a timeout, I assume the site is down.
Alex went on to describe his site as "just a quick sanity check, mostly meant to compensate for ISPs whose DNS caches get stale and that sort of thing."
As Alex suggests, his website has the fairly modest goal of letting the broad spectrum of Internet users have a "sanity check" about sites they're interested in. But Internet reliability and the five-nines metric will become more relevant within the enterprise if businesses continue to use more virtualized workforces and start sending more mission critical real-time traffic over the Internet.
I wonder if it isn't time to let go of the five-nines metric, at least for any public-network technology developed after the PSTN--i.e., cellular networks and the Internet. Five-nines is a laudable goal, but I doubt there will ever be the capital and the will available to take these now-ubiquitous networks to that level of reliability. The Internet principle of diversity is likely to be the working model for the foreseeable future: Connect to multiple networks and assume they won't all be down (or unacceptably slow) at the same time.
