Web and Business tiers of Microsoft Azure SQL databases have been marked as retired in September 2015. They were replaced with Basic, Standard, and Premium database tiers.
For more information please see the following article: https://msdn.microsoft.com/library/azure/dn741330.aspx
To support updated Microsoft Azure SQL database tiers, Sitecore Azure module must be reconfigured.
This applies to Azure Module 3.0 - 7.2 vesions.
To reconfigure existing Sitecore Azure deployments follow official instructions from Microsoft:
https://azure.microsoft.com/en-gb/documentation/articles/sql-database-upgrade-new-service-tiers/
The database will not be taken offline and will continue to work as usual during the reconfiguration process.
To create new Sitecore Azure deployments follow the instructions below:
Sitecore Azure 3.0
Sitecore Azure 3.1
Sitecore Azure 7.2