February 29, 2012 – A software bug tied to the extra calendar day took offerings from Microsoft's Windows Azure cloud platform offline for nearly 18 hours until the final fixes were put in place early Thursday.
Windows Azure service management – a platform as a service for clouds and storage – was “unavailable” or in the midst of an outage at its service sub-regions as of Wednesday evening. A Microsoft spokesperson said they became aware of the issues impacting Azure in a number of regions at 8:45 p.m. ET Tuesday. Azure engineering teams “developed, validated and deployed a fix” that resolved unavailability issues for the “majority of our customers” about 9 hours after the problem was first found. Still, 12 offerings in the north and south central U.S., and northern Europe were down from the bug until early Thursday morning.
In a blog describing and apologizing to customers on the event, Microsoft lead engineer Bill Laing noted that the outage was fixed for most users as of 4:57 a.m. and attributed it to the extra day in February in 2012.
"The issue was quickly triaged and it was determined to be caused by a software bug. While final root cause analysis is in progress, this issue appears to be due to a time calculation that was incorrect for the leap year," Laing wrote.
Microsoft did not specify on numbers of customers impacted now or in total, nor did it detail any of the known losses.
“Currently impacted customers may experience issues with Access Control 2.0, Marketplace, Service Bus and Service Bus, and the Access Control & Caching Portal and as a result may experience a loss of application functionality,” according to Microsoft spokesperson’s statement during the outage.
During this same time, the customer support service dashboard updated hourly also registered an “incident” leading to an outage with Azure’s Marketplace DataMarket in the south central U.S due to the other ongoing availability issues. That has also since been fixed, according to the dashboard. There have also been multiple media reports that this dashboard, too, had been down at times during the availability issues.
The company counts tens of thousands of customers to its cloud and as-a-service Azure offerings. Azure also experienced a widespread outage in 2009.