FDW wrapper for clustered app management

I am considering (postgres 9.3+) the idea of opening a R/W access into a clustered application by creating one fdw server from a central database to each server a cluster.

That would imply opening a port on each server inside the application, listening for incoming connections from the database and this way all the servers would become visible with R/W access.

Is that a sound idea or does it look horrible ? Would it be reasonable to connect in this way to a cluster of 1, 10, 100, 1000 or more servers ?

is there an existing xxxx_fdw wrapper that would look like a good candidate for such a direct access inside an application ? Then I would have to implement the protocol corresponding to this xxxx_fdw inside my application.

Thank you for your feedback.

Jerome