We used mongo where each DB instance had about a 1gb/s of conti uous read/write traffic, and each instance used around 1TB of memory. So it will probably work f

We used mongo where each DB instance had about a 1gb/s of conti uous read/write traffic, and each instance used around 1TB of memory. So it will probably work for you. There were some issues, some our fault, some Mongo's, but I think anything will have teething problems at that scale. Just make sure you don't treat it like a bucket. Use well defined schemas and indexes, like with any DB.