April 26, 2011, 6:11 AM — Amazon.com has promised to provide a "detailed post-mortem" on the root causes of the prolonged outage of its cloud services in recent days. Users of the Amazon services, meanwhile, may also have to explain how they got caught up in the outage.
The ensuing conversations may be uncomfortable for both Amazon and its cloud customers -- perhaps even more so for users of the services.
Cloud services overall have been remarkably reliable, which may be fostering a dangerous complacency among customers who are putting too must trust in them. This is another old and familiar story of technology hubris, one that was famously illustrated by another tech marvel, the unsinkable Titanic.
In this case, it is IT managers who will have to explain to their users -- and to their company's executives -- why they didn't have a lifeboat.
Amazon's partial outage, which began Thursday and seemed largely resolved today , was an exceptional event.
Based on data compiled by AppNeta, the uptime reliability of 40 of the largest providers of cloud-based services, including Amazon, Google, Azure and Salesforce.com, shows how well cloud providers are delivering uninterrupted services. The performance management and network monitoring firm, known as Apparent Networks until this week, captures minute-by-minute uptime and other data from cloud providers used by its customers.
The overall industry yearly average of uptime for all the cloud services providers monitored by AppNeta is 99.9948%, which equal to 273 minutes or 4.6 hours of unavailability per year.
The worst providers clock in at 99.992% or 420 minutes or 7 hours of unavailability a year.
The best providers are at 99.9994% or 3 minutes or .05 hours of unavailability a year.
The takeaway for cloud users looking at the AppNeta data is often that the risk of an outage is very low.
But that's not how the world works.
For example, Ken Brill, founder of the Uptime Institute, which researches data center issues, points to Japan's Fukushima Nuclear Power Plant. For 40 years, there were no problems at the plant. Then an earthquake and tsunami that hit in March disabled the facility with catastrophic consequences.
Brill expects a post-mortem on the nuclear plant will show at least 10 things that could have been done to help avoid that failure, reduce the magnitude of damage and made it easier or faster to recover from the disaster.