On Oct. 22, 2012, Amazon’s Elastic Compute Cloud (EC2) experienced an interruption of service lasting from approximately 10 am to 4 pm Pacific. The outage affected websites such as Reddit, Airbnb, and Netflix, among others.
Details on the outage are sparse, but this is not the first time EC2 has gone offline. Parts of EC2’s infrastructure went down twice in August of this year, and some EC2 customers experienced service interruptions lasting up to four days last April.
While no cloud service can truthfully guarantee 100% uptime, always research a cloud provider’s track record of availability before committing your essential data and computing tasks to the cloud.
Service level agreements of 99.99% for high-availability cloud hosting services are not uncommon. In the average year, that means the provider guarantees you’ll see no more than about 50 minutes of downtime. Be sure to ask for documentation of how well that percentage has been holding up.