Continued from here....
Turns out I could actually get the $50k and built my own cluster across multiple machines with a total of 128 cores.
The development has continued since and I have to say the results are fairly pleasing.
The scaling was fairly successful and it will probably distribute out quite well.
My approach was very similar to sharded databases, and although I rolled my own I suspect I could have used something off the shelf I would know it in enough detail.
https://en.wikipedia.org/wiki/Shard_(database_architecture)
e.g. MongoDB. I would do something like have shards that hold limited information of a geographical area (e.g. positions of player). Only certain regions would be replicated (e.g. neighbouring regions). A simulation client that runs external to the database but on the same local machine would do the simulation and update the shards.
In any case I have rolled my own, and I think in terms of distribution its pretty good, of course the amount of interactions between entities will always be limited so I question whether its possible to use this for a massive FPS or anything like that but otherwise should support lots of entities.