Anyone know good rule of thumb for what's in .CSDEF versus .CSCFG?

Question

I was surprised by a few questions on the 532 and 533 exam that more or less wanted to me to recall exactly what settings were in which configuration files for Cloud Services. I think at the basic level this is a pretty tough thing to discern without documentation in front of me.

For example: Scaling the instance count for a given Role is defined in the .csdef file, but the instance size for a Role is in .cscfg. It's not obvious to me why one versus the other is appropriate.

Anyone have any useful tips for remembering/recalling what goes where?

Answer 1

The main difference is that you can upload a new service configuration file (.cscfg) without redeploying the cloud service so configuration values can be changed without any downtime. There aren't many configuration settings that can go to the service configuration file (.cscfg) so just remember them and assume that all other settings go to the service definition file (.csdef).

Here's a great article on the subject: What is the Cloud Service Model and how do I package it?

Answer 2

Any on-the-fly changeable settings are in the configuration file. The definition file has several items that may only be changed with a re-deployment, along with a user-defined list of settings you'll want to change on-the-fly (the list itself is static, but the values are changeable).

You might be able to argue that some settings should go in the configuration file vs the definition file (e.g. a role's vm size), but these are not changeable.

Schemas are fully published for both the configuration file and the definition file.