[OldSchoolPro]

Interesting points.

I'm wondering about MongoDB. Have you tried it recently? It really improves with every release. We have a 20TB Mongo database and it's fast and problem free.

Also regarding the queues. In my personal experience a single RabbitMQ server with good hardware can easily handle 50GB a day.

[stuartaxelowen]

Can confirm, don't use mongo.

We're stuck with it now, and I really wish we had used Postgres for biz data and Cassandra for the high volume non-relational data. They're just materialized views on-top of your event stream anyway.