Modeling topology and orchestration relationships

[Anthony Shortland <anthony@dtosolutions.com>]

We're taking a close look at "TOSCA Specification Version 0.8.2".

We're impressed that the specification draws a clean distinction between topology (the TopologyTemplate section) and orchestration (the Plan section). We also like the fact that relationships between nodes (RelationshipTemplates) can be included explicitly since this is a mechanism that completes the ability to specify a full "node graph".

While we can see how this "node graph" might be used to describe an application's topology, our experience shows that there is a mapping between orchestration and topology that also needs to be made explicit. It is insufficient to say "my application looks like this" and "these are the steps to deploy my application" independently of one another: one also needs to be able to say how orchestration is effected in terms of its topology (e.g. "do this step on the web servers" or "restart the primary database server once the update is installed").

With that thought mind, is there an intent to define explicit relationships between the TopologyTemplate and the Plan section of the specification to enable this level of specification?

Thanks,

Anthony

Anthony Shortland

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