Open Stack

At the risk of making things more complicated, we should anticipate an eventual Cloud API standard which could be any solution from EC2/OpenStack/OCCI/... and a set of legacy interfaces for backwards compatibility.  This, as far as I see, pushes us strongly towards the multiple APIs as a presentation layer and a backend which is relatively flexible (as we also can adapt the presentation layers to convert if required without impacting the clients).

Some interfaces, such as the OpenStack one could be relatively light and the additional business logic of mapping/transforming added to the other interfaces as required.

Tim Bell
CERN