The Azure SQL Database is a distributed system in which each server hosts many databases. This sharing of resources leads to capacity constraints on operational throughput. The SQL Database handles these capacity constraints by throttling operations and closing connections that are using too many resources. SQL Database also closes connections when it alleviates operational hot spots by switching from a primary SQL Database to one of its two backup copies. Furthermore, connectivity to a SQL Database is likely to be less reliable than connectivity to a Microsoft SQL Server database on a corporate LAN. It is imperative, therefore, that applications using the SQL Database must be designed to withstand connection failures that are far more likely to occur than with Microsoft SQL Server.

One of the mantras of cloud development is design for failure. It is important that applications that use the SQL Database be designed to handle failures appropriately...