I’ve been looking for a global scale storage solution for a long time where you could start small and grow huge with minimal growing pains over time. CosmosDB from Microsoft Azure sounds like the solution I’ve been looking for.

Some of the weaknesses of previous approaches I’ve taken previously got the job done but you either ran into

Azure Table Storage

Azure SQL DB

DocumentDB

Got better with the elastic pools but still was not the turn key solution I was looking for.

Multi-homing APIs

Setting preferredLocations. Do you need to specify preferred locations for ALL locations enabled? For example, if you are replicating to US-EAST, US-WEST and CENTRAL EUROPE? When you deploy to WEST-US you change the order but if you omit central Europe from the preferred location does that mean if there is a disruption the application will not use central Europe? Inversely, if you are hosting your app in central Europe and you DON’T want your data replicated into US-EAST or US-WEST how can that be achieved?