[I work at Meteor and contributed to the MongoDB realtime driver]
Scaling low-latency data synchronization is a challenge for scalability for sure! We are gradually building better and better drivers with persistence to MongoDB.
The scalability can vary greatly depending on your application's data schema, usage patterns and amount of writes.
If you watch the mentioned talk carefully, the speaker describes a collaboration tool with log replay with a lot of actions and running from a single box.
The "running from a single box" at the end seems like it could be the most important part of the equation. Would you agree? Or rather, would that be the recommended place to start optimizing if your app runs into scaling problems?
I don't know how you could load balance meteor easily, but you could put your mongodb instance anywhere and pass in its location to meteor. This doubles your risk for downtime because of hardware failure though, your uptime is no longer as good as a system that depends on the uptime of a single machine.
Scaling low-latency data synchronization is a challenge for scalability for sure! We are gradually building better and better drivers with persistence to MongoDB.
The scalability can vary greatly depending on your application's data schema, usage patterns and amount of writes.
If you watch the mentioned talk carefully, the speaker describes a collaboration tool with log replay with a lot of actions and running from a single box.