Facebook Faces Worst Downtime in 4 Years

Update:

Facebook has clarified, in a lengthy blog post, details about this outage which it calls the worst outage of the site in four years. Earlier today, Facebook was unavailable for a lengthy period of time  - throwing continuous error messages. With Twitter too facing an attack not long ago, many thought of this being yet another planned attack against the social network. However, Facebook has clarified that it was an internal system error that caused this outage.

The blog post (read it only if you're a geek!) explains that the outage was caused due to an automated system used by Facebook. The job of this system was to find and replace invalid configuration values. The system deletes erroneous values in the cache and replaces them with configuration values that it thinks are updated values from a good persistent database. However, during the outage, the cache was replaced by erroneous values from the usually correct persistent value database. This persistent database was slightly changed by Facebook and was then interpreted as invalid. Soon after, every single client saw the invalid value and attempted to fix it. Because the fix involves making a query to a cluster of databases, that cluster was quickly overwhelmed by hundreds of thousands of queries a second. If that wasn't all, all this called a domino effect that was only stopped after Facebook turned off the site and fixed the issue.



Facebook seems to be reeling under a down time of sorts. The site is sporadically accessible and is throwing up multiple error messages.

This is the second unscheduled downtime the worlds largest social network is facing in two days. Incidentally, this also comes just a few days after the other high profile network Twitter faced an attack that exploited a security hole in the framework of the website.

As of now, these are the error messages you'd come across if you try accessing Facebook.

 

 

According to Mashable, Facebook has confirmed that its facing "Latency" issues. However, the problem could be much bigger than what it seems now. We expect a blog post soon from Facebook who are better poised to explain what caused this outage.