The Amazon Elastic Compute Cloud (EC2) outage that brought down a number of major Websites in mid-April, including social network sites Foursquare, HootSuite and Reddit, underscores the value of backup for cloud users—on traditional servers, another cloud or even another zone of their provider's cloud. Amazon took the blame for the disruption, which involved the cloud's Elastic Block Store (EBS) storage services, and said in a statement it will compensate customers.

San Francisco-based Mashery, which provides application programming interfaces to more than 100 brands, including Best Buy, Hoovers and the New York Times, escaped the outage. Mashery uses multiple Amazon zones for its own services and employs traditional data centers from Atlanta-based InterNap Network Services for additional backup. Mashery didn't think the EBS services that failed were designed for durability, and since they weren't covered by Amazon's service level agreement, it avoided EBS. 

"We had some customers whose underlying APIs used those services, and they had some challenges," says Mashery CEO Oren Michels. "It was just as if they had a database server in their center that went down."