How do cscfg files and App.config files relate to one another for Azure Worker Roles?

Question

In the "on premise" world, when creating an application like a Windows Service I'd classically use an App.config file to store a variety of configuration information about the application, from database connection strings to WCF endpoint information.

In the Azure Worker Role world, I am now presented with .cscfg files which are said to contain information "for the role".

I don't understand whether these files are there to supplement the configuration of the application, or replace App.config files entirely. How do these two files work to configure Azure Worker roles?

Answer 1

Very Basic Explanation:

Conceptually they're the same. In a traditional application, you use app.config file to define various settings related to the application (in appSettings section). Similarly, you use cscfg file to define various settings related to your cloud application (in ConfigurationSettings section). Like app.config file, you get to define other things (e.g. number of instances of your cloud application) in the cscfg file.

If you want, you can still define some of the settings in app.config file but one thing to keep in mind is that app.config file gets "packaged" and deployed and in order to change the settings, you would have to repackage your application and deploy it. However you could change the settings in a cscfg file on the fly using either the portal or Service Management API without having to repackage and redeploy the application. For example consider the scenario where you're defining the database connection string in settings file. If you specify that in app.config, in order to change it you would need to make change in app.config file --> Build the application --> publish the application. Where as in case of a cscfg file, you would just change this value in the portal.