Starting April 1, Microsoft plans to update its service level agreement (SLA) for Azure AD user authentication to 99.99%. Hitting this four-nine uptime will be an improvement over the current 99.9% SLA.

A multi-tenant identity management service, Azure AD processes tens of billions of authentications per day. To deliver on its ‘99.99% uptime’ promise, Microsoft aims to drop service credit for administrative features and include only vital user authentication and federation features under Azure AD’s new SLA. 

Any period of time when users can’t log in to the service, access applications on the Access Panel and reset passwords, accounts to service downtime. Furthermore, organisations can avail service credits if Azure AD’s uptime drops below the SLA. For instance, Microsoft offers a full-service credit when uptime falls below 95% per month.

Microsoft attributed the enhanced SLA to its ongoing program of resilience investment to improve reliability in all areas of its identity services. 

To increase the reliability of its Azure AD, Microsoft centralised architecture to scope and isolated the impact of failures to a minimum number of users; included a backup authentication service that transparently and automatically handles authentications for participating workloads; integrated Azure infrastructure authentication with regional authentication endpoints; and provided instant enforcement of policy changes with continuous access evaluation (CAE) protocol for critical Microsoft 365 services. 

“In conversations with our customers, we learned that the most critical promise of our service is ensuring that every user can sign in to the apps and services they need without interruption,’’ said Nadim Abdo, vice president of engineering at Microsoft.

“To deliver on this promise, we are updating the definition of Azure AD SLA availability to include only user authentication and federation (and removing administrative features). This focus on critical user authentication scenarios aligns our engineering investments with the vital functions that must stay healthy for customers’ businesses to run.”