服務當掉後的偵測

CNN 這篇「Netflix goes down. Twitter blows up」提到了昨天 Netflix 當了好幾個小時的情況。裡面提到了 Down Detector 這個服務:

Downdetector -- which monitors outage complaints online -- reported more than 13,000 posts from users all over the world Saturday afternoon.

到 Down Detector 網站上看,這個服務有一部份是從 social network 上挖資料:

Downdetector collects status reports from a series of sources. Through a realtime analysis of this data, our system is able to automatically determine outages and service interruptions at a very early stage. One of the sources that we analyse are reports on Twitter.

甚至還可以挖出是全域性的還是區域性的 outage...