Microsoft's Azure status page indicates that users of the service have been hit by a worldwide DNS outage that is impacting a "subset of customers". The outage was reported at 11:48 UTC today, with Microsoft stating that its engineers have determined the cause of disruption and are working on a possible fix soon.
A number of Azure-based services have been affected including SQL Database, App Service / Web Apps, API Management, Service Bus, HDInsight, Media Services and Visual Studio Team Services. Microsoft states that users will possibly be facing degraded service availability due to the incident, as its engineers try to figure out the solution to the problem. The initial update from the company is as follows:
Starting at 11:48 UTC 15 Sep, 2016 a subset of customers using DNS in multiple regions may experience difficulties connecting to their resources hosted in this region. Knock-on impact is being experienced by several additional Azure services, which are detailed in the post below. Engineers have identified a possible underlying cause, and are working to determine mitigation options. The next update will be provided in 60 minutes, or as events warrant.
As the company works to resolve the issue, a number of Azure customers have already been voicing their opinions on the matter on social media and forums. Regardless, Microsoft has stated that it is actively working to mitigate the problem and will update its Azure status page hourly, or as the situation warrants. We'll be updating this post as the situation unfolds.
Update: As Mary Jo Foley points out on Twitter, the outage seems to be mostly over and the SQL Database in the Central US region seems to be the only service still affected by the disruption as of now. Microsoft says that:
We have validated that the issues experienced by customers using SQL Database in Central US are mitigated. Our Engineering teams are working to gather additional details on the preliminary root cause before this incident is resolved. An update will be provided within 30 minutes.