High Availability Of Daughter Engines
Daughter Engines can be implemented as a Motor (a la Argent Non-Stop Motors). It can be done by specifying so during installation, or promoted when it is already installed.
When Daughter Engines are implemented as Motors, the Daughter’s SQL backend becomes the single failure point. It can be easily addressed by using SQL Server clusters, or more likely, SQL Server mirroring, which is available in SQL Server 2005 and later.