Application orchestration provides a few key features for the Puppet language. Application orchestration extends the concept of exported resources to a more targeted application, allowing the sharing of configuration items between nodes. Additionally, this feature provides a way to order Puppet runs to ensure that dependency nodes have finished building or converging prior to the nodes that require them. Application orchestration allows us to entangle multiple nodes together in an ordered run. Most importantly, configuration updates are not randomly applied on check-in, but are applied in a particular, ordered pattern.

Application orchestration has three new language constructs we'll need to use to create ordered runs that share information automatically with each other:

• Application definitions: An end-to-end description of a collection of components describing an entire application stack
• Application components: An individual component of an entire application stack
• Service resources: Resources designed to share information across application components