Yes, a single coordinator using other machines to do a lot of the work does make some otherwise very difficult problems seem more tractable. An interesting uni

Yes, a single coordinator using other machines to do a lot of the work does make some otherwise very difficult problems seem more tractable. An interesting unit for this kind of design outside the cloud would be a single rack of servers (or however much you can hook up to one switch)--assure pretty low latency to your remote RAM/disk.