Interesting story on how to setup MongoDB in production. It talks about 2, 3, 4, even 5 replica sets, it's pros/con's and shows you how these setups deal with reconfiguring primary / secondary configurations on the fly. Apart from that, a fair amount of the presentation explains what parameters are important for sizing your HW configuration in terms of RAM.
Chris Harris and Alvin Richards present "MongoDB in Production".
Chris Harris is European Solution Architect at 10gen and Alvin Richards is Senior Director, Enterprise Engineering at 10gen
How should we setup MongoDB in production and what resources do we need?
This session covers how to setup up replication for data protection and high availability to protect you against server failure, network failure, power outage and complete data center collapse. Understand the metrics used to decide your working set and disk setup. We also cover an introduction to MMS as a monitoring system as well as an overview of backup strategies.