Why Does The Cloud Stop Computing? Lessons From Hundreds Of Service Outages

We conducted a cloud outage study (COS) of 32 popular Internet services. We analyzed 1247 headline news and public post-mortem reports that detail 597 unplanned outages that occurred within a 7-year span from 2009 to 2015. We analyzed outage duration, root causes, impacts, and fix procedures. This study reveals the broader availability landscape of modern cloud services and provides answers to why outages still take place even with pervasive redundancies.