I want to allow my shared hosting sites to use MongoDB, however as they are all on the same VPS server I am able to get mongo to create databases, and asign them to users bu
I dont believe this can be done with MongoDB. If at all possible, you might want to create volumes on your server that have quota's set on them, and spin up multiple instances of mongod
You should keep in mind, however, that MongoDB attempts to keep as much data as possible in memory. This could pose performance issues for customers when their data gets swapped to disk in exchange for someone else's data.