Thank you for the VMware answer.
I have also some dynamic data to load and I couldn't use cache for it of course, but I find a way to manage it (also not realy the best).
I use the same way as VRA do to collect vCenter information.
I scheduled a data collection for these dynamic data and store it into a property inside the VRA VirtualMachine Entity.
Of course, the data are not "real time" data, but in my use case, it was enough...
With VRO, it's really easy to schedule a Workflow and save a property in VRA VirtualMachine Entity, that's why I use this.
Emmanuel.