Amazon S3 rents storage over the internet and charges fees based on the volume of transfers and size of the files stored.
Developers can use the service to quickly add storage capacity to their systems without having to purchase any hardware or software.
S3 is part of Amazon's broader web services bundle, which also includes its Elastic Compute Cloud rental servers and the Mechanical Turk.
"We know that many of our customers, including a multitude of teams within Amazon, are using S3 in mission-critical ways and need a formal commitment from us in order to make commitments to their own users and customers," said Jeff Barr, services evangelist at Amazon, on a company blog.
The Amazon S3 Service Level Agreement guarantees an uptime of 99.9 percent. Customers will be issued a 10 percent credit if system availability falls below 99.9 percent, and a 25 percent credit if it falls below 99 percent.
A downtime of 0.1 percent per month represents a system crash for seven hours 26 minutes based on a 31-day month. Mission critical systems typically require 99.999 percent uptime, or no more than 45 minutes downtime per month.
Business writer Nicholas Carr suggested that the Amazon S3 SLA illustrates the advantage of hosted services over in-house IT.
"Utilities will compete directly with one another on critical performance standards, like reliability and security, as well as pricing," Carr wrote on his Rough Type blog.
"That competition promises rapidly to drive up standards and push down prices to the benefit of the utilities' customers."
In house IT, by comparison, lacks a direct competitor to drive improvements.
Amazon offers S3 uptime guarantee
By Tom Sanders on Oct 10, 2007 10:28PM