Why would anything need to go to db? :/ Going to db should always be a last, final resort.

People often seem to think a db is the only way to write any webapp, and that everything must depend on the db. That's bad architecture.

In the case of Mibbit, db access is only done for writes, lazily, in the background.

The bottlenecks for me, are CPU, network, and ram. And yes, you can throw servers at it, if you're frivolous and don't intend to make any money. I decided to go the other way and be profitable ;)