Microsoft Blames Azure Outage on OS Upgrade

In a post on its Windows Azure blog, Microsoft said after the upgrade "the deployment service within Windows Azure began to slow down due to networking issues" on Friday. "This caused a large number of servers to time out and fail," which brought some applications down, according to the post.

Microsoft said the Fabric Controller, a feature built into Azure that manages network resources and performs functions such as load balancing, automatically began taking steps to recover applications that were affected and move them to different servers. Only applications that were running in a single instance on the network went down during the outage, the company said.