Amazon S3 service promises 99.9 percent uptime

Amazon's S3 storage service is growing up and adopting a Service Level Agreement (SLA).

In a blog post, Amazon Web Services (AWS) detailed its SLA, which defines a minimum level of performance and imposes penalties if S3 (all resources) doesn't deliver. Amazon noted that formalizing the SLA was the result of customer feedback--and a lot of customers asking for one.

The details:

Effective Oct. 1, S3 commits to 99.9 percent uptime monthly. If S3 fails (via a service unavailable or internal error message) and delivers uptime of less than 99 percent the customer can apply for a service credit of 25 percent. If uptime is between 99 percent and 99.9 percent you can apply for a credit of 10 percent of S3 charges.

A few points to ponder:

• Kudos for Amazon for creating and SLA. Over time most Web services will offer one.
• Notice that we're talking 99.9 percent uptime, not the 99.999 percent that enterprises have come to expect. The message: S3 is a fine service, but a big company can expect to outsource its storage needs to the cloud.