Facebook suffered its worst outage in four years and thousands of users were unable to reach the site this morning.
Facebook is the largest social networking site below the sky and this outage was the third in the last 48 hours and it was reported to be due to an error in one if their automated systems.
Facebook has posted an apology to its 500 million users, saying that an automated system incorrectly handled an error message on the site.
“The intent of the automated system is to check for configuration values that are invalid in the cache and replace them with updated values from the persistent store. This works well for a transient problem with the cache but it doesn’t work when the persistent store is invalid. The way to stop the feedback cycle was quite painful – we had to stop all traffic to this database cluster, which meant turning off the site. Once the databases had recovered and the root cause had been fixed, we slowly allowed more people back onto the site.”, facebook said.
Facebook would have learnt a big lesson from this outage.