RE: [tosca] RE: updated operational model

[Chris Lauwers <lauwers@ubicity.com>]

 

We need to revisit this. Operations are not events.

 

Operations are how we respond to events (at least one way we can, there's policy triggers, too).

 

That is incorrect. The v1.3 spec states the following (in 1.3):

 

Both node and relationship types may define lifecycle operations to implement the behavior an orchestration engine can invoke when instantiating a service template. For example, a node type for some software product might provide a âcreateâ operation to handle the creation of an instance of a component at runtime, or a âstartâ or âstopâ operation to handle a start or stop event triggered by an orchestration engine. Those lifecycle operations are backed by implementation artifacts such as scripts or Chef recipes that implement the actual behavior.

An orchestration engine processing a TOSCA service template uses the mentioned lifecycle operations to instantiate single components at runtime, and it uses the relationship between components to derive the order of component instantiation.

 

This clearly states that operations are invoked by an orchestrator to perform lifecycle operations (e.g. to create an initial deployment). There is nothing that suggests that operations are used to respond to events. The only construct in the language that is used to handle events is the Policy.

 

Chris