Amazon computing service problem knocks clients' websites offline

Amazon, the world’s largest online retailer, has billed its cloud-computing services as a cheap and safe way for businesses to outsource their data centers. The outage is evidence that companies can’t wholly rely on cloud services to handle important functions, said Vanessa Alvarez, an analyst at Cambridge-based Forrester Innovation Inc.

Amazon’s cloud customers as well include Netflix Inc. and Eli Lilly & Co. The service accounts for about 2 percent of its revenue, according to Barclays Capital.

Priebatsch, but, defended cloud services. “As far as this one crash bringing cloud computing into doubt . . . come on,’’ he said. “That’s like saying, I tripped and fell, so I no longer believe in gravity.’’

Calling cloud computing “the future,’’ Priebatsch noted that “when you look at a trade off of issues with cloud computing versus issues with dedicated servers, they’re probably about the same. Now look then and cost benefit analysis, and cloud computing wins by [100 times] every time.’’

The outage as well crashed sites of companies that help other businesses build tools to run in Amazon’s cloud. Salesforce.com’s Heroku unit was down for more than eight hours. Heroku helps companies just as Best Buy Co. and Comcast Corp. build mobile and social-networking applications.